View in EDS HTML Full Text PDF Full Text

Socioeconomic Status and Children with Intellectual Disability in China

Saved in:
Bibliographic Details
Title: Socioeconomic Status and Children with Intellectual Disability in China
Language: English
Authors: Zheng, X., Chen, R., Li, N., Du, W., Pei, L., Zhang, J., Ji, Y., Song, X., Tan, L., Yang, R.
Source: Journal of Intellectual Disability Research. Feb 2012 56(2):212-220.
Availability: Wiley-Blackwell. 350 Main Street, Malden, MA 02148. Tel: 800-835-6770; Tel: 781-388-8598; Fax: 781-388-8232; e-mail: cs-journals@wiley.com; Web site: http://www.wiley.com/WileyCDA/
Peer Reviewed: Y
Page Count: 9
Publication Date: 2012
Document Type: Journal Articles
Reports - Research
Descriptors: Social Class, Intervals, Mental Retardation, Foreign Countries, Socioeconomic Status, Correlation, Young Children, Mild Mental Retardation, Severe Mental Retardation, At Risk Persons, Gender Differences, Mothers, Age Differences, Educational Attainment, Family Income, Place of Residence, Rural Areas, Prenatal Influences
Geographic Terms: China
DOI: 10.1111/j.1365-2788.2011.01470.x
ISSN: 0964-2633
Abstract: Background: Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID. Methods: Data for children aged 0-6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (OR[subscript a]) (95% confidence intervals) estimated the independent effects of these factors. Results: For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, OR[subscript a] 1.47 (1.15-1.88); severe ID, OR[subscript a] 1.32 (1.00-1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, OR[subscript a] 3.00 (2.19-4.12); low income, OR[subscript a] 2.28 (1.63-3.19); lower middle income, OR[subscript a] 1.72 (1.27-2.33); middle income, OR[subscript a] 1.73 (1.28-2.36). Conclusions: There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.
Abstractor: As Provided
Number of References: 24
Entry Date: 2012
Accession Number: EJ954114
Database: ERIC
Full text is not displayed to guests.
FullText Links:
  – Type: pdflink
    Url: https://content.ebscohost.com/cds/retrieve?content=AQICAHj0k_4E0hTGH8RJwT4gCJyBsGNe_WN95AvKlDbXJGqwxwFUSfgr00WN4RdVWSH0ikUuAAAA4TCB3gYJKoZIhvcNAQcGoIHQMIHNAgEAMIHHBgkqhkiG9w0BBwEwHgYJYIZIAWUDBAEuMBEEDFkrBY3Yzq7yREN09QIBEICBmYjNJGyJpuWLuGyMd-yEZsuXM4VxswGmI3yS0oB0aBVYKa7iLUsQ3ODquLq1DqpyKdF2hLJVmZgo3M0pp18On1QhSQ1b_bJqkhWQXQfbCyui8k48H7Kca8j4_-KDyGOmQgHPm2B_EQ8uGqCqbwc8hLmcRW-T-ggulHZkZ3SsGd3NewScCIZB-LhyYBpNCmHT3icn8sRGHqJWSA==
Text:
  Availability: 1
  Value: <anid>AN0070470157;eul01feb.12;2019Jun04.10:45;v2.2.500</anid> <title id="AN0070470157-1">Socioeconomic status and children with intellectual disability in China. </title> <p>Background  Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID. Methods  Data for children aged 0–6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (ORa) (95% confidence intervals) estimated the independent effects of these factors. Results  For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, ORa 1.47 (1.15–1.88); severe ID, ORa 1.32 (1.00–1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, ORa 3.00 (2.19–4.12); low income, ORa 2.28 (1.63–3.19); lower middle income, ORa 1.72 (1.27–2.33); middle income, ORa 1.73 (1.28–2.36). Conclusions  There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.</p> <p>Keywords: China; intellectual disability; mental retardation; socioeconomic status; children</p> <p>Persons with intellectual disability (ID) or mental retardation have historically been classified into two groups based on the presence or absence of organic/pathological causes. The pathological group consists mainly of persons with severe ID [intelligence quotient (IQ) < 50], and the nonpathological/familial group consists mostly of persons with mild ID (IQ = 50–70). Several studies have shown that low socioeconomic status (SES) are overrepresented among those with mild ID ([<reflink idref="bib24" id="ref1">24</reflink>]; [<reflink idref="bib27" id="ref2">27</reflink>]; [<reflink idref="bib17" id="ref3">17</reflink>]), whereas persons with severe ID are evenly distributed in the community ([<reflink idref="bib16" id="ref4">16</reflink>]).</p> <p>Despite the close relationship between SES and mild ID, there is growing disagreement about the estimated impact of SES on persons with ID. In their analysis of the relationship between SES and ID of unknown cause in children, Croen <emph>et al</emph>. ([<reflink idref="bib9" id="ref5">9</reflink>]) found that children of less educated mothers had an increased risk of both mild and severe ID controlling for maternal race and other factors. Similarly, Chapman <emph>et al</emph>. ([<reflink idref="bib4" id="ref6">4</reflink>]) revealed that sociodemographic factors play a key role across all levels of ID. Yet few studies, with the exception of a Bangladesh study ([<reflink idref="bib11" id="ref7">11</reflink>]), have examined the relationship between SES and ID in developing countries, and in particular among the 1.3 billion Chinese ([<reflink idref="bib16" id="ref8">16</reflink>]). There is an urgent need for such research, which would have a profound effect on the appropriate planning of support, education and medical prevention services for Chinese children affected by ID. If studies could show a link between SES and mild or severe ID, strategies could be developed to improve education with the aim of preventing ID. Providing the special care and rehabilitation to these children with ID is a financial and psychological burden for families and an economic challenge for state and local Governments. Thus, it is necessary to determine as early as possible whether a child is at an increased risk for ID so as to give the family an opportunity for early intervention.</p> <p>In the past three decades, a substantial literature has been published (mostly in Chinese) on Chinese children with ID. Prevalence rates for ID among children have been reported at 1.73% ([<reflink idref="bib18" id="ref9">18</reflink>]; [<reflink idref="bib36" id="ref10">36</reflink>]) in the 1990s and 0.93% ([<reflink idref="bib30" id="ref11">30</reflink>]) in 2001. The ratio of mild to severe ID remains steady at 1.2–1.3 ([<reflink idref="bib30" id="ref12">30</reflink>]), which is much lower than that in the developed countries ([<reflink idref="bib16" id="ref13">16</reflink>]). Children from rural areas are more likely to have ID than those from urban areas ([<reflink idref="bib18" id="ref14">18</reflink>]; [<reflink idref="bib36" id="ref15">36</reflink>]; [<reflink idref="bib31" id="ref16">31</reflink>]). In addition, children living in the western region of China have a higher prevalence rate of ID than those living in the middle or eastern regions (1.56%, 1.26% and 1.1%, respectively), which is in line with regional discrepancies in the mortality rates for children aged under 5 years ([<reflink idref="bib25" id="ref17">25</reflink>]). Although studies have shown that the risk of ID increases with lower maternal education, lower family income and mother's older age at delivery ([<reflink idref="bib19" id="ref18">19</reflink>]; [<reflink idref="bib23" id="ref19">23</reflink>]), no study has specifically considered the influence of sociodemographic factors on the prevalence of mild and severe ID.</p> <p>Using data from the Second National Sampling Survey on Disability in China, which was conducted in 2006, this study aimed to investigate the relationship between sociodemographic factors and ID in Chinese children aged 0–6 years.</p> <hd id="AN0070470157-2">Methods</hd> <p></p> <hd id="AN0070470157-3">Study population</hd> <p>The present study derives an ID sub‐population from the Second National Sampling Survey on Disability conducted from 1 April to 30 May 2006 in China. The aims of this survey were: (<reflink idref="bib1" id="ref20">1</reflink>) to investigate the prevalence of disability in China, the family characteristics of persons with disability and the needs of this population in terms of social services and supports; and (<reflink idref="bib2" id="ref21">2</reflink>) to review and revise the policy commitment to disabled persons since the First National Sampling Survey on Disabled Persons was conducted in 1987. With the approval of the State Council of the People's Republic of China, the Leading Group of the Second China National Sample Survey on Disability conducted the survey. All participants completed informed consents given by the Chinese Government ([<reflink idref="bib20" id="ref22">20</reflink>]). Utilising stratified, multiphase and cluster probability sampling design, the project team sampled participants from all provinces, autonomous regions and municipalities of mainland China. The four levels of sampling frame were county, town, village and community. The initial sampling frame was based on population, household, disability, registration and economic data of counties as collected by the provincial survey office using the most up‐to‐date population and address information from the Ministry of Civil Affairs and Public Security. The sample size at each level equalled the proportion of the population in that level to that of the province. A total of 734 counties were sampled, accounting for 20% of all counties in China. Using this same method, teams sampled four towns in each county, then two villages in each town and one community in each village. All persons in the sampled community were thoroughly investigated, and all children aged 0–6 years were examined and diagnosed by trained doctors. A total of 5964 communities were sampled in 2006, with an average of 420 persons in each community.</p> <p>The children studied here lived in households headed by a mother and/or father. Information could not be obtained on every child's family because of the design of the original questionnaire. This limitation is addressed in <emph>Discussion</emph>.</p> <hd id="AN0070470157-4">Screening and diagnosis of intellectual disability</hd> <p>All children born between 1 April 1999 and 1 April 2006 in the selected communities were first screened by developmental paediatricians and psychiatrists using the standardised Denver Development Screening (DDST; [<reflink idref="bib8" id="ref23">8</reflink>]). If the child was suspected of having ID, a definitive diagnosis was made using the Gesell Development Inventory (standardised in China and revised in 1985 and 1990, respectively; [<reflink idref="bib8" id="ref24">8</reflink>]) or the Japanese version of the Vinland Social Maturity Scale (standardised and restandardised in 1987 and 1994 ([<reflink idref="bib33" id="ref25">33</reflink>]; [<reflink idref="bib6" id="ref26">6</reflink>]).</p> <p>The DDST was standardised and published in 1967 and is one of the most widely used screening tools with children aged 1 month to 6 years ([<reflink idref="bib30" id="ref27">30</reflink>]). With help of Dr Frankenburg in 1978, the Department of Pediatrics of Shanghai Sixth People's Hospital used the DDST to evaluate the intelligence of 1041 children aged 2 weeks to 6 years ([<reflink idref="bib35" id="ref28">35</reflink>]). Results indicated that the DDST was an appropriate tool for screening Chinese children with developmental delay. The DDST was standardised by the Beijing Children's Health Care Institute in 1982 and applied nationally after that. Despite its widespread use, concerns have been raised about its validity ([<reflink idref="bib14" id="ref29">14</reflink>]; [<reflink idref="bib6" id="ref30">6</reflink>]). The DDST underwent a significant revision and restandardisation and has since been known as the Denver‐II ([<reflink idref="bib12" id="ref31">12</reflink>]). [<reflink idref="bib5" id="ref32">5</reflink>]) compared results from the Denver‐II and the DDST against those from the Gesell Diagnosis Inventory and found that the sensitivity of the Denver‐II was 89.5% and the specificity 93.2%, suggesting that the Denver‐II is a better screening tool for developmental delay among children in China. The Second National Sampling Survey on Disability used the DDST to screen for ID to be consistent with the first sampling survey and because the Denver‐II had not yet been standardised nationally in China. With an administration time of 15–20 min, the DDST evaluates four domains of functioning: personal–social (23 items), fine motor adaptive (30 items), language (20 items) and gross motor (31 items). Performance on age‐appropriate tasks within these domains determines whether a child is classified as being in the normal range, as having a delay or as having a suspected delay. Two or more delays in any domain constitute a delay, and one delay or two cautions constitutes a questionable or suspected delay.</p> <p>The Gesell Development Inventory was translated and standardised by the Beijing Children's Health Care Institute. It consists of five behavioural domains: adaptive, gross motor, fine motor, language and personal social behaviours ([<reflink idref="bib35" id="ref33">35</reflink>]). Children suspected of having ID were tested in the adaptive domain and were diagnosed as having ID if their disability quotient (DQ) was less than 72. Performance was judged to be within the normal range if the DQ was more than 78. Children aged 7 months to 6 years whose DQ on the adaptive domain was between 72 and 78 were then diagnosed and classified according to their score on the Japanese version of the Vinland Social Maturity Scale. Children younger than 7 months whose DQ on the adaptive domain was between 72 an 78 were then diagnosed as having mild ID if their scores in the language and personal social behaviours domains were both less than normal ([<reflink idref="bib8" id="ref34">8</reflink>]). The Japanese version of the Vinland Social Maturity Scale was translated and standardised by the Beijing Medical University in 1987 and restandardised in 1994, with 132 items in six domains including self‐help, locomotion, occupation, communication, socialisation and self‐direction areas. Experiences with application of this scale showed that it had satisfactory reliability and validity ([<reflink idref="bib33" id="ref35">33</reflink>]).</p> <p>Severity of ID was classified in the Second National Sampling Survey on Disability as mild (DQ 55–75), moderate (DQ 40–54), severe (DQ 26–39) or extremely severe (DQ ≤ 25) with regard to the Criteria for Disability ([<reflink idref="bib8" id="ref36">8</reflink>]) issued by the State Council of the People's Republic of China in 2006. For the purposes of this analysis, children were divided into two groups: those diagnosed with mild ID (DQ 55–75) or severe ID (DQ < 55).</p> <p>We treated children' age as continuous and categorised child's sex as male or female; residence as rural or urban; geographic region as east, middle or west; mother's age at delivery as <20, 20–29, 30–34 or 35+ years; maternal education as illiterate, primary school/junior high school or senior high school and higher; family income as lowest, low, lower middle, middle, upper middle or high; and parental disability as being ID disabled or not.</p> <hd id="AN0070470157-5">Data analysis</hd> <p>All data collected from field surveys were inputted, cleaned and checked, and analysed using Stata version 10.0. Information on sex, age, residence, geographic region, mother's age at delivery, maternal education, family income and parental disability was abstracted from the questionnaires. In univariate analysis, crude odds ratios (OR) (95% confidence intervals) were calculated to show the effect of sociodemographic factors on ID. Adjusted odds ratios (OR<subs>a</subs>) (95% confidence intervals) were computed using logistic regression to estimate the independent effects of these factors.</p> <hd id="AN0070470157-6">Quality control</hd> <p>Strict quality control measures were in place during the survey. The survey protocol and definitions were discussed several times by experts in the fields of disability, health, population and statistics; they also received a favourable evaluation by experts from the Division of Statistics of the United Nations. Before the field survey commenced, training courses were held at national and local levels for all investigators, and all local clinic specialists were trained in the screening and diagnosis of disability. Three pilot studies were conducted. Results of a postsurvey quality check showed omission rates of 1.31 per 1000 in the resident population and 1.12 per 1000 in the disabled population in 2006 ([<reflink idref="bib34" id="ref37">34</reflink>]).</p> <hd id="AN0070470157-7">Results</hd> <p>In the study population of 106 774 children aged 0–6 years, a total of 1308 were diagnosed with ID, representing 12.25 per 1000 children surveyed. Among those children with ID, 52% (<emph>n</emph> = 686) had a diagnosis of mild ID and 48% (<emph>n</emph> = 622) had a diagnosis of severe ID (Table 1). The prevalence rates of mild ID and severe ID were 0.65% and 0.59%, respectively. The ratio for mild/severe ID was 1.1 which was much lower than the ratio predicted from a normally approximated IQ distribution.</p> <p>1 Characteristics of the study population*</p> <p> <ephtml> <table><thead valign="bottom"><tr><th /><th><bold>Non‐ID (<italic>n</italic> = 105 466)</bold></th><th><bold>Mild ID (<italic>n</italic> = 686)</bold></th><th><bold>Severe ID (<italic>n</italic> = 622)</bold></th></tr><tr><th><bold><italic>n</italic> (%)</bold></th><th><bold><italic>n</italic> (%)</bold></th><th><bold>OR<sub>c</sub> (95% CI)</bold></th><th><bold><italic>n</italic> (%)</bold></th><th><bold>OR<sub>c</sub> (95% CI)</bold></th></tr></thead><tbody valign="top"><tr><td>Child sex</td><td /><td /><td /><td /><td /></tr><tr><td> Male</td><td>57 956 (54.95)</td><td>410 (59.77)</td><td>1.22 (1.04–1.42)</td><td>360 (57.88)</td><td>1.13 (0.96–1.32)</td></tr><tr><td> Female</td><td>47 510 (45.05)</td><td>276 (40.23)</td><td>1</td><td>262 (42.12)</td><td>1</td></tr><tr><td>Mother's age at delivery (years)</td><td /><td /><td /><td /><td /></tr><tr><td> <20</td><td>2 836 (2.69)</td><td>25 (3.64)</td><td>1.52 (1.00–2.32)</td><td>24 (3.86)</td><td>1.56 (1.01–2.40)</td></tr><tr><td> 20–29</td><td>71 089 (67.40)</td><td>411 (59.91)</td><td>1</td><td>386 (62.06)</td><td>1</td></tr><tr><td> 30–34</td><td>23 711 (22.48)</td><td>170 (24.78)</td><td>1.24 (1.00–1.54)</td><td>147 (23.63)</td><td>1.14 (0.91–1.44)</td></tr><tr><td> 35+</td><td>7 830 (7.42)</td><td>80 (11.66)</td><td>1.77 (1.35–2.31)</td><td>65 (10.45)</td><td>1.53 (1.14–2.05)</td></tr><tr><td>Parental disability</td><td /><td /><td /><td /><td /></tr><tr><td> ID</td><td>635 (0.60)</td><td>630 (91.84)</td><td>14.67 (10.74–20.05)</td><td>574 (92.28)</td><td>13.81 (9.87–19.30)</td></tr><tr><td> Non‐ID</td><td>104 831 (99.40)</td><td>56 (8.16)</td><td>1</td><td>48 (7.72)</td><td>1</td></tr><tr><td>Maternal education</td><td /><td /><td /><td /><td /></tr><tr><td> Illiterate</td><td>10 551 (10.00)</td><td>147 (21.43)</td><td>4.53 (3.63–5.66)</td><td>150 (24.12)</td><td>5.67 (4.51–7.13)</td></tr><tr><td> Primary school/junior high school</td><td>77 353 (73.34)</td><td>485 (70.70)</td><td>2.04 (1.71–2.43)</td><td>428 (68.81)</td><td>2.21 (1.83–2.67)</td></tr><tr><td> Senior high school and higher</td><td>17 562 (16.65)</td><td>54 (7.87)</td><td>1</td><td>44 (7.07)</td><td>1</td></tr><tr><td>Residence</td><td /><td /><td /><td /><td /></tr><tr><td> Rural</td><td>72 998 (69.21)</td><td>571 (83.24)</td><td>2.21 (1.86–2.63)</td><td>495 (79.58)</td><td>1.73 (1.44–2.09)</td></tr><tr><td> Urban</td><td>32 468 (30.79)</td><td>115 (16.76)</td><td>1</td><td>127 (20.42)</td><td>1</td></tr><tr><td>Region</td><td /><td /><td /><td /><td /></tr><tr><td> East</td><td>36 059 (34.19)</td><td>283 (41.25)</td><td>1.45 (1.19–1.75)</td><td>196 (31.51)</td><td>0.92 (0.74–1.14)</td></tr><tr><td> Middle</td><td>30 572 (28.99)</td><td>166 (24.20)</td><td>1</td><td>180 (28.94)</td><td>1</td></tr><tr><td> West</td><td>38 835 (36.82)</td><td>237 (34.55)</td><td>1.13 (0.92–1.37)</td><td>246 (39.55)</td><td>1.08 (0.88–1.32)</td></tr><tr><td>Family income†</td><td /><td /><td /><td /><td /></tr><tr><td> Lowest (10%)</td><td>9 947 (9.43)</td><td>111 (16.18)</td><td>2.82 (2.22–3.59)</td><td>127 (20.42)</td><td>4.29 (3.38–5.44)</td></tr><tr><td> Low (10%)</td><td>9 430 (8.94)</td><td>82 (11.95)</td><td>2.20 (1.69–2.86)</td><td>83 (13.34)</td><td>2.96 (2.26–3.87)</td></tr><tr><td> Lower middle (20%)</td><td>22 913 (21.73)</td><td>197 (28.72)</td><td>2.17 (1.77–2.67)</td><td>140 (22.51)</td><td>2.05 (1.63–2.59)</td></tr><tr><td> Middle (20%)</td><td>20 875 (19.79)</td><td>120 (17.49)</td><td>1.45 (1.15–1.84)</td><td>123 (19.77)</td><td>1.98 (1.56–2.52)</td></tr><tr><td> Upper middle (20%)</td><td>20 808 (19.73)</td><td>91 (13.27)</td><td>1.11 (0.86–1.43)</td><td>85 (13.67)</td><td>1.37 (1.05–1.79)</td></tr><tr><td> High (20%)</td><td>21 493 (20.38)</td><td>85 (12.39)</td><td>1</td><td>64 (10.29)</td><td>1</td></tr></tbody></table> </ephtml> </p> <p>1 *  Only children with no missing data on any variables were included.</p> <ulist> <item>2 †   Given the large discrepancy in income by region and urban/rural residence, the population was divided into six groups according to region (east, middle, west) and urban/rural residence. Households in each group were organised by per capita income: the 10% most disadvantaged households in each of the six groups were combined to form the lowest income group; the second 10% most disadvantaged households were combined to form the low income group; the 20% least disadvantaged were combined to form the high income group; and the remaining 60% were divided equally to make up the lower middle, middle and upper middle income groups. Therefore, the standardised income group was calculated for data analysis.</item> <item>3 ID, intellectual disability; OR<subs>c</subs>, crude odds ratio; CI, confidence interval.</item> </ulist> <hd id="AN0070470157-8">Child characteristics</hd> <p>As shown in Table 1, children with mild ID were more likely to be male [OR 1.22 (1.04–1.42)], but there was no significant difference in terms of sex for children with severe ID.</p> <hd id="AN0070470157-9">Mother's age at delivery</hd> <p>Compared to mothers aged 20–29 years at delivery, those younger than 20 were more likely to have a child with mild ID [OR 1.52 (1.00–2.32)]. Mothers aged 30–34 [OR 1.24 (1.00–1.54)] and 35 years and older [OR 1.77 (1.35–2.31)] also had an increased risk of having a child with mild ID. For severe ID, the pattern was similar, with an increased risk for mothers younger than 20 [OR 1.56 (1.01–2.40)] and those 35 and older [OR 1.53 (1.14–2.05)]. No significant effect was seen for mothers aged 30–34 years for severe ID.</p> <hd id="AN0070470157-10">Parent disability</hd> <p>A child whose mother or father had a diagnosis of ID had more than 14 times the risk [OR 14.67 (10.74–20.05)] of having mild ID (prevalence rates were 81.04‰ and 5.97‰, respectively, for children whose parent did and did not have ID). A similar pattern was seen for children with severe ID whose parent had diagnosed ID [OR 13.81 (9.87–19.30)].</p> <hd id="AN0070470157-11">Sociodemographic factors</hd> <p>Illiterate mothers were more likely to have a child with mild ID [OR 4.53 (3.63–5.66)]. Mothers with only a primary school education had a moderately increased risk of having a child with mild ID [OR 2.04 (1.71–2.43)]. This monotonic pattern was similar and significant for children with severe ID: illiterate mother [OR 5.67 (4.51–7.13)], primary school education [OR 2.21 (1.83–2.67)]. The income gradient effect appeared in both groups, such that families with the lowest income were more likely to have a child with mild [OR 2.82 (2.22–3.59)] or severe [OR 4.29 (3.38–5.44)] ID. Risk decreased as income increased: Families in the low, lower middle and upper middle income groups, respectively, were more likely to have a child with mild [OR 2.20 (1.69–2.86), OR 2.17 (1.77–2.67), OR 1.45 (1.15–1.84)] or severe [OR 2.96 (2.26–3.87), OR 2.05 (2.26–3.87), OR 1.98 (1.56–2.52)] ID. This effect was more apparent for severe ID. Families in rural areas were more likely to have a child with either mild or severe ID, but the influence was stronger for mild ID [OR 2.21 (1.86–2.63) vs. OR 1.73 (1.44–2.09) for severe ID]. Finally, families from the eastern region were more likely to have a child with mild ID; no significant effect was found for severe ID (Table 1).</p> <p>In the logistic regression model with severe ID, all predictor variables in the univariate analysis remained significant and the income gradient effect held except that women younger than 20 no longer had an increased risk of having a child with severe ID compared to women aged 20–29 years. In the logistic regression model with mild ID, only 35 and older continued to be a significant risk factor in terms of mother's age at delivery. Risk was increased among male children born to illiterate mothers. Families from the eastern region and parents with ID were more likely to have a child with mild ID. The income gradient effect remained in the model except among the low income group (Table 2).</p> <p>2 OR a and 95% CI for ID and sociodemographic factors*</p> <p> <ephtml> <table><thead valign="bottom"><tr><th /><th><bold>Mild ID</bold></th><th><bold>Severe ID</bold></th></tr><tr><th><bold>OR<sub>a</sub></bold></th><th><bold>95% CI</bold></th><th><italic><bold>P</bold></italic></th><th><bold>OR<sub>a</sub></bold></th><th><bold>95% CI</bold></th><th><italic><bold>P</bold></italic></th></tr></thead><tbody valign="top"><tr><td>Child sex</td><td /><td /><td /><td /><td /><td /></tr><tr><td> Male</td><td>1.23</td><td>1.06–1.44</td><td>0.008</td><td>1.14</td><td>0.97–1.34</td><td>0.105</td></tr><tr><td> Female</td><td>1</td><td>Reference</td><td /><td>1</td><td>Reference</td><td /></tr><tr><td>Mother's age at delivery (years)</td><td /><td /><td /><td /><td /><td /></tr><tr><td> <20</td><td>1.31</td><td>0.86–1.96</td><td>0.207</td><td>1.25</td><td>0.82–1.90</td><td>0.295</td></tr><tr><td> 20–29</td><td>1</td><td>Reference</td><td /><td>1</td><td>Reference</td><td /></tr><tr><td> 30–34</td><td>1.10</td><td>0.92–1.32</td><td>0.304</td><td>1.06</td><td>0.87–1.28</td><td>0.295</td></tr><tr><td> 35+</td><td>1.47</td><td>1.15–1.88</td><td>0.002</td><td>1.32</td><td>1.00–1.73</td><td>0.042</td></tr><tr><td>Maternal education</td><td /><td /><td /><td /><td /><td /></tr><tr><td> Illiterate</td><td>1.74</td><td>1.21–2.52</td><td>0.003</td><td>2.45</td><td>1.65–3.63</td><td><0.001</td></tr><tr><td> Primary school/junior high school</td><td>1.21</td><td>0.89–1.33</td><td>0.436</td><td>1.49</td><td>1.06–2.09</td><td>0.022</td></tr><tr><td> Senior high school and higher</td><td>1</td><td>Reference</td><td /><td>1</td><td>Reference</td><td /></tr><tr><td>Residence</td><td /><td /><td /><td /><td /><td /></tr><tr><td> Rural</td><td>1.93</td><td>1.55–2.41</td><td><0.001</td><td>1.35</td><td>1.09–1.67</td><td>0.006</td></tr><tr><td> Urban</td><td>1</td><td>Reference</td><td /><td>1</td><td>reference</td><td /></tr><tr><td>Region</td><td /><td /><td /><td /><td /><td /></tr><tr><td> East</td><td>1.63</td><td>1.34–1.98</td><td><0.001</td><td>1.02</td><td>0.83–1.25</td><td>0.857</td></tr><tr><td> Middle</td><td>1</td><td>Reference</td><td /><td>1</td><td>reference</td><td /></tr><tr><td> West</td><td>1.09</td><td>0.89–1.34</td><td>0.414</td><td>1</td><td>0.82–1.22</td><td>0.999</td></tr><tr><td>Parental disability</td><td /><td /><td /><td /><td /><td /></tr><tr><td> ID</td><td>8.81</td><td>6.45–12.06</td><td><0.001</td><td>7.10</td><td>5.09–9.91</td><td><0.001</td></tr><tr><td> Non‐ID</td><td>1</td><td>Reference</td><td /><td>1</td><td>Reference</td><td /></tr><tr><td>Family income</td><td /><td /><td /><td /><td /><td /></tr><tr><td> Lowest</td><td>2.01</td><td>1.55–2.82</td><td><0.001</td><td>3.00</td><td>2.19–4.12</td><td><0.001</td></tr><tr><td> Low</td><td>1.73</td><td>1.27–2.38</td><td>0.001</td><td>2.28</td><td>1.63–3.19</td><td><0.001</td></tr><tr><td> Lower middle</td><td>1.93</td><td>1.48–2.50</td><td><0.001</td><td>1.72</td><td>1.27–2.33</td><td><0.001</td></tr><tr><td> Middle</td><td>1.31</td><td>0.99–1.74</td><td>0.058</td><td>1.73</td><td>1.28–2.36</td><td><0.001</td></tr><tr><td> Upper middle</td><td>1.07</td><td>0.79–1.44</td><td>0.673</td><td>1.29</td><td>0.93–1.78</td><td>0.132</td></tr><tr><td> High</td><td>1</td><td>Reference</td><td /><td>1</td><td>Reference</td><td /></tr><tr><td>Age</td><td /><td /><td /><td /><td /><td /></tr><tr><td /><td>1.04</td><td>1.01–1.09</td><td>0.015</td><td>1.11</td><td>1.06–1.15</td><td>0.015</td></tr></tbody></table> </ephtml> </p> <ulist> <item>4 *  Only children with no missing data on any variables were included.</item> <item>5 OR<subs>a</subs>, adjusted odds ratio; CI, confidence interval; ID, intellectual disability.</item> </ulist> <hd id="AN0070470157-12">Discussion</hd> <p>The results of this study show that sociodemographic factors are strongly related to the prevalence of both mild and severe ID in children aged 0–6 years in China and that the relationships are similar for both types of ID. The risk of having either type of ID was monotonically increased among children born to women with low levels of education and to families with low per capita incomes. Families in rural areas and women aged 35 years and older were also more likely to have a child with mild or severe ID. The risk of having ID was significantly increased among children born to a parent with ID. For mild ID in particular, risk increased among male children and among children from the eastern region of China. The degree of association of all sociodemographic variables with severe ID was higher than with mild ID.</p> <p>The present findings show that the income gradient relationship existed beyond the poverty threshold model, meaning that not only children in the least disadvantaged income group but children in all income groups were more likely to be diagnosed with mild or severe ID. Although this relationship differs from the pattern found in developed countries ([<reflink idref="bib27" id="ref38">27</reflink>]; [<reflink idref="bib9" id="ref39">9</reflink>]; [<reflink idref="bib17" id="ref40">17</reflink>]), the role of SES in a person's health has been established across countries and throughout the life span ([<reflink idref="bib28" id="ref41">28</reflink>]). Families with higher income are more likely to be able to afford medical services such as prenatal examinations, genetic counselling and early interventions for ID children. In this study, the protective effect of high‐level maternal education was stronger than that of high‐level family income. Previous studies suggested similar protective effect for better maternal education, because less educated mothers may have fewer opportunities to learn ID prevention ([<reflink idref="bib7" id="ref42">7</reflink>]) and less use of prenatal services ([<reflink idref="bib29" id="ref43">29</reflink>]). The present findings may also imply that level of maternal education and family income could be independently associated with ID risk among children.</p> <p>The present results indicate that sociodemographic factors have a similar relationship with both mild and severe ID, which is not consistent with results from developed countries that have shown such a relationship for mild ID only. Yet other studies have indicated that sociodemographic factors play a key role across all levels of ID ([<reflink idref="bib9" id="ref44">9</reflink>]; [<reflink idref="bib4" id="ref45">4</reflink>]). The two‐group model is supported by the fact that an identifiable medical aetiology is present in up to 70% of children with severe ID but only 24% of children with mild ID ([<reflink idref="bib32" id="ref46">32</reflink>]; [<reflink idref="bib1" id="ref47">1</reflink>]; [<reflink idref="bib22" id="ref48">22</reflink>]; [<reflink idref="bib2" id="ref49">2</reflink>]). However, almost all of the biomedical causes of severe ID are strongly sociodemographic factors typically linked to mild ID ([<reflink idref="bib1" id="ref50">1</reflink>]). Focusing exclusively on specific biomedical causes of ID is of little use in developing ID prevention plans because the costs of technical screening and gene diagnosis are beyond what most Chinese families can afford, especially those in rural areas. The current data, which show that children living in rural areas are more likely to have ID, also support a public health approach to studying ID in China.</p> <p>The present study contributes to existing evidence that women aged 35 years and older are more likely to have a child with either mild or severe ID ([<reflink idref="bib10" id="ref51">10</reflink>]; [<reflink idref="bib3" id="ref52">3</reflink>]). This finding not only supports the relationship between severe ID and Down syndrome ([<reflink idref="bib13" id="ref53">13</reflink>]; [<reflink idref="bib15" id="ref54">15</reflink>]) but indicates that other underlying causes of ID may be associated with older maternal age.</p> <p>The ascertained mild : severe ratio was 1.1 which was one‐fifth of that ratio predicted from a normally approximated IQ distribution ([<reflink idref="bib21" id="ref55">21</reflink>]). The ratio for found in survey for disabled children aged 0–6 years in 2001 was 1.2 which was similar with what we found ([<reflink idref="bib30" id="ref56">30</reflink>]). Some researchers said DDST was not sensitive to find the persons with mild ID ([<reflink idref="bib26" id="ref57">26</reflink>]). There were literatures which said it was very hard to find mild ID in early childhood until children went into elementary school ([<reflink idref="bib21" id="ref58">21</reflink>]). This figure also indicated that first intervention strategies for ID such as intervention for birth defect, prepregnancy approaches is much more important for China because the economic and society burden for care of severe ID was much expensive and could not affordable for Chinese.</p> <p>This study has several limitations. First, one should be very cautious in using these results to estimate the influence of sociodemographic factors on the risk of ID because these results are based on cross‐sectional survey data. Although mother's age at delivery was computed, and maternal education was a relatively stable variable, there is no information about the causal relationship between economic status and ID. Ongoing surveillance data and logistical measures of effect are needed to complement existing research efforts ([<reflink idref="bib4" id="ref59">4</reflink>]). The China Disabled Persons' Federation has conducted follow‐up monitoring on disability annually since the 2006 Second National Sampling Survey on Disability. Those valuable data can provide researchers with accurate and specific information on children with disability (Xiaoying [<reflink idref="bib34" id="ref60">34</reflink>]). Second, consistency in classification of ID is certainly a challenge and one which can make it difficult to compare individual studies, for example, how severe ID may be differentially defined across studies and whether the moderate group is included with the severe or the mild group. Third, some etiological studies may have excluded causes such as Down syndrome and thus in these studies the relationship with maternal age could be quite different from what we found. Fourth, the children studied here lived in households headed by a mother and/or father. Information could not be obtained on every child's family because of the design of the questionnaire, which made it impossible to compare the characteristics of the children headed by a mother/father and those not headed by a mother/father. Children living in households headed by grandparents were not included in this study because of lacking data on parents who did not live with them. Therefore, the current finding may not be generalised to a general child population. So caution should be taken when interpreting the relationship between sociodemographic factors and ID.</p> <p>In sum, although both biological and sociodemographic factors are important in terms of ID risk, the present findings show that there is a significant relationship between sociodemographic factors and ID. Similar patterns exist for both mild and severe ID. These findings are important because they provide the first clear and comprehensive evidence that sociodemographic factors have a relationship with mild and severe ID in China, and they offer a broader biosocial perspective on preventing ID among children in China.</p> <hd id="AN0070470157-13">Acknowledgements</hd> <p>This study was funded by National Key Project (<reflink idref="bib973" id="ref61">973</reflink>) of Study on Interaction Mechanism of Environment and Genetic of Birth Defect in China (No. 2007CB5119001), State Key Funds of Social Science Project (Research on Disability Prevention Measurement in China, No. 09&ZD072), National Yang Zi Scholar Program, 211 and 985 projects of Peking University (No. 20020903).</p> <ref id="AN0070470157-14"> <title> Footnotes </title> <blist> <bibl id="bib1" idref="ref20" type="bt">1</bibl> <bibtext> Both authors contributed equally to this work.</bibtext> </blist> </ref> <ref id="AN0070470157-15"> <title> References </title> <blist> <bibtext> Accardo P. J. (1998) Overview: mental retardation. Mental Retardation and Developmental Disabilities Research Reviews 4, 1.</bibtext> </blist> <blist> <bibl id="bib2" idref="ref21" type="bt">2</bibl> <bibtext> Cans C., Wilhelm L., Baille M. F., du Mazaubrun C., Grandjean H. & Rumeau‐Rouquette C. (1999) Aetiological findings and associated factors in children with severe mental retardation. Developmental Medicine and Child Neurology 41, 233 – 9.</bibtext> </blist> <blist> <bibl id="bib3" idref="ref52" type="bt">3</bibl> <bibtext> Chapman D. A., Scott K. G. & Mason C. A. (2002) Early risk factors for mental retardation: role of maternal age and maternal education. American Journal on Mental Retardation 107, 46 – 59.</bibtext> </blist> <blist> <bibl id="bib4" idref="ref6" type="bt">4</bibl> <bibtext> Chapman D. A., Scott K. G. & Stanton‐Chapman T. L. (2008) Public health approach to the study of mental retardation. American Journal on Mental Retardation 113, 102 – 16.</bibtext> </blist> <blist> <bibl id="bib5" idref="ref32" type="bt">5</bibl> <bibtext> Chen J. Y., Wei M., He L., Jiang L. & Liu F. (2008) Research on the application condition in practice of Shanghai Denver II Development Screening. Chinese Journal of Child Health Care 16, 393 – 4.</bibtext> </blist> <blist> <bibl id="bib6" idref="ref26" type="bt">6</bibl> <bibtext> Chen Y. & Chen D. (2007) Comparison of diagnosic features and rating scales on mental retardation. Journal of applied Clinic Pediatrics 22, 958 – 61.</bibtext> </blist> <blist> <bibl id="bib7" idref="ref42" type="bt">7</bibl> <bibtext> Cheng Z. P. (2003) Research in deformity of neural tube. Practical Preventive Medicine 10, 21 – 5.</bibtext> </blist> <blist> <bibl id="bib8" idref="ref23" type="bt">8</bibl> <bibtext> China Disabled Persons' Federation (CDPF) (2006) Working Manual for the Second National Sampling Survey on Disabled. The Office of National Sampling Survey of the Disabled, Beijing.</bibtext> </blist> <blist> <bibl id="bib9" idref="ref5" type="bt">9</bibl> <bibtext> Croen L. A., Grether J. K. & Selvin S. (2001) The epidemiology of mental retardation of unknown cause. Pediatrics 107, e86.</bibtext> </blist> <blist> <bibtext> Drews C. D., Yeargin‐Allsopp M., Decoufle P. & Murphy C. C. (1995) Variation in the influence of selected sociodemographic risk factors for mental retardation. American Journal of Public Health 85, 329 – 34.</bibtext> </blist> <blist> <bibtext> Durkin M. S., Khan N. Z., Davidson L. L., Huq S., Munir S., Rasul E. et al. (2000) Prenatal and postnatal risk factors for mental retardation among children in Bangladesh. American Journal of Epidemiology 152, 1024 – 33.</bibtext> </blist> <blist> <bibtext> Frankenburg W. K., Dodds J. B., Archer P., Shapiro H. & Bresnick B. (1990) Denver‐II Screening Manual. Denver Developent Materials, Denver, CO.</bibtext> </blist> <blist> <bibtext> Gardner R. J. & Sutherland G. R. (1996) Chromosome Abnormalities and Genetic Counseling. Oxford University Press, New York.</bibtext> </blist> <blist> <bibtext> Glascoe F. P. (2001) Are overreferrals on developmental screening tests really a problem? Archives of Pediatrics & Adolescent Medicine 155, 54 – 9.</bibtext> </blist> <blist> <bibtext> International Clearinghouse for Birth Defects Monitoring Systems (ICBDMS) (2000) Annual Report 1999. International Centre for Birth Defects, Rome.</bibtext> </blist> <blist> <bibtext> Leonard H. & Wen X. (2002) The epidemiology of mental retardation: challenges and opportunities in the new millennium. Mental Retardation and Developmental Disabilities Research Reviews 8, 117 – 34.</bibtext> </blist> <blist> <bibtext> Leonard H., Petterson B., De Klerk N., Zubrick S. R., Glasson E., Sanders R. et al. (2005) Association of sociodemographic characteristics of children with intellectual disability in Western Australia. Social Science & Medicine 60, 1499 – 513.</bibtext> </blist> <blist> <bibtext> Li A., Li L. & Qian Y. (1994) Preliminary analysis of factors causing mental retardation in China. China Preventive Medicine 28, 284 – 6.</bibtext> </blist> <blist> <bibtext> Liang A. M., Wu Y. H., Zhang X. L., Wu Y. H., Yang W. P., Bian Y. et al. (2006) Prevalence rate of children with intellectual disability aged 0–6. Chinese Journal of Practical Pediatrics 11, 119 – 23.</bibtext> </blist> <blist> <bibtext> Liu J., Chi I., Chen G., Song X. & Zheng X. (2009) Prevalence and correlates of functional disability in Chinese older adults. Geriatrics & Gerontology International 9, 253 – 61.</bibtext> </blist> <blist> <bibtext> Mash J. E. & Wolfe A. D. (2002) Abnormal Child Psychology, 2nd edn. Thomson Learning Press, Wadsworth.</bibtext> </blist> <blist> <bibtext> Murphy C. C., Boyle C., Schendel D., Decoufle P. & Yeargin‐Allsopp M. (1998) Epidemiology of mental retardation in children. Mental Retardation and Developmental Disabilities Research Reviews 4, 6 – 13.</bibtext> </blist> <blist> <bibtext> Qiu W. Y. (2008) Causes and preventive strategies for Children with Intellectual disability. Modern Preventive Medicine 35, 2665 – 6.</bibtext> </blist> <blist> <bibtext> Roeleveld N., Zielhuis G. A. & Gabreels F. (1997) The prevalence of mental retardation: a critical review of recent literature. Developmental Medicine and Child Neurology 39, 125 – 32.</bibtext> </blist> <blist> <bibtext> Rudan I., Chan K. Y., Zhang J. S. F., Theodoratou E., Feng X. L., Salomon J. A. et al. (2010) Causes of deaths in children younger than 5 years in China in 2008. The Lancet 375, 1083 – 9.</bibtext> </blist> <blist> <bibtext> Shen X. M. & Jing X. M. (2006) Pediatrics of Development and Behavior. Jiangsu Science and Technology Press, Suzhou.</bibtext> </blist> <blist> <bibtext> Stromme P. & Magnus P. (2000) Correlations between socioeconomic status, IQ and aetiology in mental retardation: a population‐based study of Norwegian children. Social Psychiatry and Psychiatric Epidemiology 35, 12 – 18.</bibtext> </blist> <blist> <bibtext> Winkleby M. A., Jatulis D. E., Frank E. & Fortmann S. P. (1992) Socioeconomic status and health: how education, income, and occupation contribute to risk factors for cardiovascular disease. American Journal of Public Health 82, 816 – 20.</bibtext> </blist> <blist> <bibtext> Wu J., Qin L., Ren A. G., Zheng J. C., Chen X. & Li Z. (2003) Equity in prenatal health cares in 21 Chinese southern countries. Chinese Journal of Reproductive Health 14, 21 – 5.</bibtext> </blist> <blist> <bibtext> Xie Z. H., Bo S. Y., Zhang X. T., Liu M., Zhang Z. X., Yang X. L. et al. (2008) Sampling survey on intellectual disability in 0 similar to 6‐year‐old children in China. Journal of Intellectual Disability Research 52, 1029 – 38.</bibtext> </blist> <blist> <bibtext> Xiong N., Zhang Z., Ye Q., Zhang S., Si J., Chen Y. et al. (2009) Investigation on prevalance and cause of children with mental disability in China. Chinese Journal of Child Health Care 17, 48 – 50.</bibtext> </blist> <blist> <bibtext> Yeargin‐Allsopp M., Drews C. D., Decoufle P. & Murphy C. C. (1995) Mild mental retardation in black and white children in metropolitan Atlanta: a case‐control study. American Journal of Public Health 85, 324 – 38.</bibtext> </blist> <blist> <bibtext> Zhang Z., Zuo Q., Lei Z., Chen R., Huang L. & He G. (1995) The restandarization of the adaptive scale of infant and children. Chinese Journal of Clinical Psychology 3, 12 – 17.</bibtext> </blist> <blist> <bibtext> Zheng X., Chen G., Song X., Liu J., Yan L., Du W. et al. (2011) Twenty‐year trends in the prevalence of disability in China. WHO Bulletin (in press). Available at: <ulink href="http://www.who.int/bulletin/online%5ffirst/11‐089730.pdf">http://www.who.int/bulletin/online%5ffirst/11‐089730.pdf</ulink> (retrieved 20 July 2011).</bibtext> </blist> <blist> <bibtext> Zhu Y., Lu S., Tang C., Wang Z. & Song J. (1983) Application of DDST in China: retrospective and prospective era. Journal of Clinical Pediatrics 1, 129 – 32.</bibtext> </blist> <blist> <bibtext> Zuo Q., Lei Z., Zhang Z., Chen R., Huang L., He G. et al. (1994) An epidemiological study on etiology of mental retardation. National Medical Journal of China 74, 134 – 9.</bibtext> </blist> </ref> <aug> <p>By X. Zheng; R. Chen; N. Li; W. Du; L. Pei; J. Zhang; Y. Ji; X. Song; L. Tan and R. Yang</p> <p>Reported by Author; Author; Author; Author; Author; Author; Author; Author; Author; Author</p> </aug> <nolink nlid="nl1" bibid="bib24" firstref="ref1"></nolink> <nolink nlid="nl2" bibid="bib27" firstref="ref2"></nolink> <nolink nlid="nl3" bibid="bib17" firstref="ref3"></nolink> <nolink nlid="nl4" bibid="bib16" firstref="ref4"></nolink> <nolink nlid="nl5" bibid="bib11" firstref="ref7"></nolink> <nolink nlid="nl6" bibid="bib18" firstref="ref9"></nolink> <nolink nlid="nl7" bibid="bib36" firstref="ref10"></nolink> <nolink nlid="nl8" bibid="bib30" firstref="ref11"></nolink> <nolink nlid="nl9" bibid="bib31" firstref="ref16"></nolink> <nolink nlid="nl10" bibid="bib25" firstref="ref17"></nolink> <nolink nlid="nl11" bibid="bib19" firstref="ref18"></nolink> <nolink nlid="nl12" bibid="bib23" firstref="ref19"></nolink> <nolink nlid="nl13" bibid="bib20" firstref="ref22"></nolink> <nolink nlid="nl14" bibid="bib33" firstref="ref25"></nolink> <nolink nlid="nl15" bibid="bib35" firstref="ref28"></nolink> <nolink nlid="nl16" bibid="bib14" firstref="ref29"></nolink> <nolink nlid="nl17" bibid="bib12" firstref="ref31"></nolink> <nolink nlid="nl18" bibid="bib34" firstref="ref37"></nolink> <nolink nlid="nl19" bibid="bib28" firstref="ref41"></nolink> <nolink nlid="nl20" bibid="bib29" firstref="ref43"></nolink> <nolink nlid="nl21" bibid="bib32" firstref="ref46"></nolink> <nolink nlid="nl22" bibid="bib22" firstref="ref48"></nolink> <nolink nlid="nl23" bibid="bib10" firstref="ref51"></nolink> <nolink nlid="nl24" bibid="bib13" firstref="ref53"></nolink> <nolink nlid="nl25" bibid="bib15" firstref="ref54"></nolink> <nolink nlid="nl26" bibid="bib21" firstref="ref55"></nolink> <nolink nlid="nl27" bibid="bib26" firstref="ref57"></nolink> <nolink nlid="nl28" bibid="bib973" firstref="ref61"></nolink>
Header DbId: eric
DbLabel: ERIC
An: EJ954114
AccessLevel: 3
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Socioeconomic Status and Children with Intellectual Disability in China
– Name: Language
  Label: Language
  Group: Lang
  Data: English
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Zheng%2C+X%2E%22">Zheng, X.</searchLink><br /><searchLink fieldCode="AR" term="%22Chen%2C+R%2E%22">Chen, R.</searchLink><br /><searchLink fieldCode="AR" term="%22Li%2C+N%2E%22">Li, N.</searchLink><br /><searchLink fieldCode="AR" term="%22Du%2C+W%2E%22">Du, W.</searchLink><br /><searchLink fieldCode="AR" term="%22Pei%2C+L%2E%22">Pei, L.</searchLink><br /><searchLink fieldCode="AR" term="%22Zhang%2C+J%2E%22">Zhang, J.</searchLink><br /><searchLink fieldCode="AR" term="%22Ji%2C+Y%2E%22">Ji, Y.</searchLink><br /><searchLink fieldCode="AR" term="%22Song%2C+X%2E%22">Song, X.</searchLink><br /><searchLink fieldCode="AR" term="%22Tan%2C+L%2E%22">Tan, L.</searchLink><br /><searchLink fieldCode="AR" term="%22Yang%2C+R%2E%22">Yang, R.</searchLink>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="SO" term="%22Journal+of+Intellectual+Disability+Research%22"><i>Journal of Intellectual Disability Research</i></searchLink>. Feb 2012 56(2):212-220.
– Name: Avail
  Label: Availability
  Group: Avail
  Data: Wiley-Blackwell. 350 Main Street, Malden, MA 02148. Tel: 800-835-6770; Tel: 781-388-8598; Fax: 781-388-8232; e-mail: cs-journals@wiley.com; Web site: http://www.wiley.com/WileyCDA/
– Name: PeerReviewed
  Label: Peer Reviewed
  Group: SrcInfo
  Data: Y
– Name: Pages
  Label: Page Count
  Group: Src
  Data: 9
– Name: DatePubCY
  Label: Publication Date
  Group: Date
  Data: 2012
– Name: TypeDocument
  Label: Document Type
  Group: TypDoc
  Data: Journal Articles<br />Reports - Research
– Name: Subject
  Label: Descriptors
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Social+Class%22">Social Class</searchLink><br /><searchLink fieldCode="DE" term="%22Intervals%22">Intervals</searchLink><br /><searchLink fieldCode="DE" term="%22Mental+Retardation%22">Mental Retardation</searchLink><br /><searchLink fieldCode="DE" term="%22Foreign+Countries%22">Foreign Countries</searchLink><br /><searchLink fieldCode="DE" term="%22Socioeconomic+Status%22">Socioeconomic Status</searchLink><br /><searchLink fieldCode="DE" term="%22Correlation%22">Correlation</searchLink><br /><searchLink fieldCode="DE" term="%22Young+Children%22">Young Children</searchLink><br /><searchLink fieldCode="DE" term="%22Mild+Mental+Retardation%22">Mild Mental Retardation</searchLink><br /><searchLink fieldCode="DE" term="%22Severe+Mental+Retardation%22">Severe Mental Retardation</searchLink><br /><searchLink fieldCode="DE" term="%22At+Risk+Persons%22">At Risk Persons</searchLink><br /><searchLink fieldCode="DE" term="%22Gender+Differences%22">Gender Differences</searchLink><br /><searchLink fieldCode="DE" term="%22Mothers%22">Mothers</searchLink><br /><searchLink fieldCode="DE" term="%22Age+Differences%22">Age Differences</searchLink><br /><searchLink fieldCode="DE" term="%22Educational+Attainment%22">Educational Attainment</searchLink><br /><searchLink fieldCode="DE" term="%22Family+Income%22">Family Income</searchLink><br /><searchLink fieldCode="DE" term="%22Place+of+Residence%22">Place of Residence</searchLink><br /><searchLink fieldCode="DE" term="%22Rural+Areas%22">Rural Areas</searchLink><br /><searchLink fieldCode="DE" term="%22Prenatal+Influences%22">Prenatal Influences</searchLink>
– Name: Subject
  Label: Geographic Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22China%22">China</searchLink>
– Name: DOI
  Label: DOI
  Group: ID
  Data: 10.1111/j.1365-2788.2011.01470.x
– Name: ISSN
  Label: ISSN
  Group: ISSN
  Data: 0964-2633
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Background: Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID. Methods: Data for children aged 0-6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (OR[subscript a]) (95% confidence intervals) estimated the independent effects of these factors. Results: For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, OR[subscript a] 1.47 (1.15-1.88); severe ID, OR[subscript a] 1.32 (1.00-1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, OR[subscript a] 3.00 (2.19-4.12); low income, OR[subscript a] 2.28 (1.63-3.19); lower middle income, OR[subscript a] 1.72 (1.27-2.33); middle income, OR[subscript a] 1.73 (1.28-2.36). Conclusions: There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.
– Name: AbstractInfo
  Label: Abstractor
  Group: Ab
  Data: As Provided
– Name: Ref
  Label: Number of References
  Group: RefInfo
  Data: 24
– Name: DateEntry
  Label: Entry Date
  Group: Date
  Data: 2012
– Name: AN
  Label: Accession Number
  Group: ID
  Data: EJ954114
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=eric&AN=EJ954114
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1111/j.1365-2788.2011.01470.x
    Languages:
      – Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 9
        StartPage: 212
    Subjects:
      – SubjectFull: Social Class
        Type: general
      – SubjectFull: Intervals
        Type: general
      – SubjectFull: Mental Retardation
        Type: general
      – SubjectFull: Foreign Countries
        Type: general
      – SubjectFull: Socioeconomic Status
        Type: general
      – SubjectFull: Correlation
        Type: general
      – SubjectFull: Young Children
        Type: general
      – SubjectFull: Mild Mental Retardation
        Type: general
      – SubjectFull: Severe Mental Retardation
        Type: general
      – SubjectFull: At Risk Persons
        Type: general
      – SubjectFull: Gender Differences
        Type: general
      – SubjectFull: Mothers
        Type: general
      – SubjectFull: Age Differences
        Type: general
      – SubjectFull: Educational Attainment
        Type: general
      – SubjectFull: Family Income
        Type: general
      – SubjectFull: Place of Residence
        Type: general
      – SubjectFull: Rural Areas
        Type: general
      – SubjectFull: Prenatal Influences
        Type: general
      – SubjectFull: China
        Type: general
    Titles:
      – TitleFull: Socioeconomic Status and Children with Intellectual Disability in China
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Zheng, X.
      – PersonEntity:
          Name:
            NameFull: Chen, R.
      – PersonEntity:
          Name:
            NameFull: Li, N.
      – PersonEntity:
          Name:
            NameFull: Du, W.
      – PersonEntity:
          Name:
            NameFull: Pei, L.
      – PersonEntity:
          Name:
            NameFull: Zhang, J.
      – PersonEntity:
          Name:
            NameFull: Ji, Y.
      – PersonEntity:
          Name:
            NameFull: Song, X.
      – PersonEntity:
          Name:
            NameFull: Tan, L.
      – PersonEntity:
          Name:
            NameFull: Yang, R.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 02
              Type: published
              Y: 2012
          Identifiers:
            – Type: issn-print
              Value: 0964-2633
          Numbering:
            – Type: volume
              Value: 56
            – Type: issue
              Value: 2
          Titles:
            – TitleFull: Journal of Intellectual Disability Research
              Type: main
ResultId 1