Introduction

The United Nations Convention on the Rights of Persons with Disabilities defines disability as “long-term physical, mental, intellectual or sensory impairments which, in interaction with various barriers, may hinder a person’s full and effective participation in society on an equal basis with others”.¹ In children, disabilities are mental, social or physical function limitations experienced by a child in comparison to other children of his or her age. Children with disabilities are an extremely vulnerable group, they are more likely to be victims of violence and to encounter barriers to exert their human rights.^2,3

Despite the global interest in disability, there is little information about the situation of children with disability. The use of different definitions, questionnaires and methodologies pose serious challenges to obtain reliable regional and global estimates of disability. Despite these limitations, evidence suggests that there is a higher prevalence of children with disability in low and middle income countries compared to high income countries.⁴ In Mexico, disability statistics are scarce. In 2014, more than 7 million people lived with disability (6% of the population), while 16 million reported at least one limitation to perform daily activities (13.2% of the population).⁵ However, these statistics refer to the general population and not to children specifically; to our knowledge no estimates of children with disability or functional difficulties in Mexico are available.

Disability has been linked to several factors. During early childhood, girls experience a higher prevalence of disability; however, as children get older there is a shift in this trend and disability becomes more prevalent in boys.⁶ Also, children from minority ethnic groups are at a higher risk of disability compared to other children.¹ Family characteristics also play an important role in disability, compared to children without disability, children with disability are more likely to live with a single parent, have mothers with lower education levels, and have mothers with higher rates of depression or health-related problems.⁷ In Mexico, even though disability questions are included in national surveys, information on related factors for children with disability remains unknown.⁸

This study aimed to 1) estimate the prevalence of severe functional difficulties and disability (SFD) in a nationally representative sample of children ages 5 to 17 in Mexico, 2) identify factors associated with severe SFD, and 3) estimate the probabilities of severe physical, cognitive, and socioemotional SFD associated with discrete population profiles.

Materials and methods

This study is based on the 2015 National Survey of Children and Women (ENIM 2015, in Spanish), which was part of the 5th round of the UNICEF’s Multiple Indicator Cluster Survey Programme.⁹ Briefly, the ENIM 2015 was a multistage, stratified, and clustered national survey. The survey was designed to estimate a several health and well-being indicators for women and children, with representativeness for rural and urban areas, as well as for five regions: Northwest, Northeast, Central, Mexico City-State of Mexico, and South. Houses with children under 5-years old and in rural areas were oversampled to generate enough sample size for children under 5-years and the indigenous population. Four questionnaires were applied in electronic tablets: 1) household questionnaire; 2) women’s questionnaire (for women 15 to 49); 3) a questionnaire for children and adolescents ages 5 to 17, given to their mothers; 4) a questionnaire for children under 5 years old, answered by their mothers. Further information about the ENIM 2015 can be found elsewhere.¹⁰ All participants were required to provide signed informed consent before the beginning of the survey (for children and adolescents, it was provided by the legal guardian). All procedures were approved by the Research and Ethics Review Boards of the National Institute of Public Health of Mexico.

Results

A total of 11 607 children aged 5 to 17 years participated in the ENIM 2015, of which 50.7% were girls. The majority of children lived in a non-indigenous household (90.6%), in urban areas (73.6%), and 45.3% lived in a poor or very poor household. The majority of children were 10 to 14 years old (41.4%), lived with both parents (69%), and had no educational lag (94.7%). Adults in 43.4% of the households used psychological discipline and in 33.3% used physical discipline. Most of the mothers were 20 to 35 years old (41.8%), 28.3% had basic education level or less, and 20.9% presented depressive symptoms. There were no significant differences by child’s gender (table I).

Table I Demographic and household characteristics of children 5 to 17 years old. Mexico, ENIM 2015 

In table II we present the prevalence of SFD by domain. SFD in at least one domain were experienced by 11.2% of the children, boys having a higher prevalence compared to girls (12.7 and 9.7%, respectively). SFD seeing, hearing, walking, or dressing/feeding were observed in 2% of the children. SFD to be understood within or outside the household, learning, memorizing or focusing was reported by 3% of the children, with a higher prevalence in boys (4.1%) than girls (2.6%). In the socioemotional dimension, 8.3% of the children presented severe functional difficulties in at least one of the following domains: daily anxiety, daily depression, daily behavioral problems, accepting change or making friends.

Table II Children 5 to 17 years old with severe functional difficulties or disabilities in any of the domains. Mexico, ENIM 2015 

The bivariate associations between SFD in the cognitive, socioemotional and physical dimensions, and household, child and mother’s characteristics are presented in table III. Children living in the poorest households had higher odds of presenting physical or cognitive SFD compared to children in the richest households (physical OR 2.86, 95%CI 1.48,5.51; cognitive OR 2.81, 95%CI 1.63,4.86). Children living in urban areas had 33% higher odds of presenting a socioemotional SFD compared to children in rural areas (OR 1.33, 95%CI 1.05,1.69). Children living with only one parent were 46% more likely to present a socioemotional SFD and 43% more likely to present a cognitive SFD compared to children who live with both parents (OR 1.46, 95%CI 1.17,1.82; OR 1.43, 95%CI 1.01,2.04, respectively). Children of mothers with basic education had 2.56 and 2.38 higher odds of presenting a physical or cognitive SFD compared to children whose mother had college education (OR 2.56, 95%CI 1.26,5.2; OR 2.38, 95%CI 1.40,4.06, respectively). Children of mothers with maternal depression had twice the odds of presenting any SFD in any of the three dimensions, compared to children whose mothers had no depression symptoms (any SFD: OR 2.26, 95%CI 1.86,2.75; physical: OR 2.37, 95%CI 1.59,3.53; cognitive OR: 2.79, 95%CI 2.03,3.84; socioemotional OR: 2.11, 95%CI 1.67,2.67). Children exposed to any psychological discipline in the household had 1.29 higher odds of presenting any SFD (OR 1.29, 95%CI 1.04,1.58) and 1.33 higher odds for socioemotional SFD compared to children without psychological discipline in the household (OR 1.33, 95%CI 1.05,1.69). Boys had higher odds than girls of presenting any SFD (OR 1.34, 95%CI 1.10,1.63), as well as cognitive (OR 1.61, 95%CI 1.21,2.15) or socioemotional SFD (OR 1.32, 95%CI 1.05,1.66).

Table III Association between having at least one severe functional difficulty or disability and demographic, maternal, and characteristics of children 5 to 17 years old. Mexico, ENIM 2015 

Table IVand figure 1 present adjusted odds ratios of the sociodemographic predictors found to be significant in the previous analysis (poor households, sex, maternal basic education level, ethnicity or area). Based on the multivariate models we estimated the predicted probability of presenting SFD in each domain based on sociodemographic profiles. The adjusted population probability of presenting physical SFD among 5- to 17-years-old children was 2.03, 2.15% in non-indigenous households, 2.58% in children of mothers with primary or lower education level, and to 2.73% among children of mothers with primary or lower education levels that live in non-indigenous households. For cognitive SFD, the adjusted population probability was 3.25%, being 5.33% for boys living in poor or very poor households, 6.41% if children that had a mother with primary or lower education, and 6.77% if they lived in a non-indigenous household. As for socioemotional SFD, adjusted population probability of presenting SFD was 7.95%, increasing to 10.13% among boys living in urban areas.

Table IV Adjusted odds ratio and probabilities for the association of population profiles and severe functional difficulties and disability (SFD). Mexico, ENIM 2015 

* This figure describes the predicted probabilities of severe functional difficulties and disability (SFD) in each domain for discrete population profiles. In the three dimensions we observe that as we add risk factors to the profiles the predicted probability of SFD increases

Figure 1 Predicted probabilities for discrete population profiles. Mexico, ENIM 2015* 

Discussion

In this study we aimed to estimate the prevalence of SFD and disability in children ages 5 to 17 in Mexico, to identify associated factors, and to document how discrete population profiles predict physical, cognitive, and socioemotional SFD. We found that 11.2% of children 5 to 17-years old have a SFD in at least one of the 14 domains. The most prevalent SFD were on the socioemotional dimension (8.3%). The associated risk factors for physical, cognitive, and socioemotional SFD were: living in a poor household, being a boy, having a mother with basic education or less, and being from a non-indigenous background or living in an urban area.

There is a lack of consistent definitions and methodologies to measure disability at the population level; current estimates often underestimate the prevalence because of the low sensitivity of the instruments.¹³ In 2011 UNICEF and the Washington Group on Disability and Statistics (WG) developed and instrument designed to measure disability in children ages 2 to 17; this instrument was included in the MICS survey, to produce a more reliable estimate of the prevalence of children with disability and to identify children at greater risk of suffering limited social participation due to a functional disability.¹⁴

Previous MICS rounds, using a different questionnaire on disability (TQ questionnaire) instead of the WG-UNICEF module, found that in most countries 14 to 35% of children ages 2- to 9-years-old screened positive to the disability module. Furthermore, they found that children from minority ethnic groups were at an increased risk of disability, disability prevalence was higher in rural areas, and there were no important differences by sex.1 Mexico was one of the first countries to include the UNICEF-WG module in a national survey; hence, our results are not comparable to other MICS waves or national surveys. Still, some of our findings are consistent with previous literature. For instance, we observed an association between lower maternal education and higher odds of having disability; this finding is consistent with results from MICS 3 from other developing countries.¹⁵ Similarly, Mexican children from the poorest quintile of wealth have higher odds of having a SFD, which has also been described in other countries.¹⁶

We found strong associations of SFD with maternal depression symptoms, violent or psychological discipline at home, and educational lag. A meta-analysis found that mothers of children with developmental disabilities are at higher risk of depression compared to mothers of children developing normally;¹⁷ on the other hand, several studies report that children of mothers with depression have adverse consequences, such as behavior problems, deficits in cognitive performance and academic achievement. In addition, maternal depression is associated with disturbances in mother-child interaction.¹⁸ In our study, we found an association between maternal depression and the odds of having a SFD; however, due to the cross-sectional nature of the data we cannot rule out reverse causality.

We were able to determine specific population profiles associated with a higher risk for disability; however, the nature and impact of such profiles differs according to the disability dimension. While for the physical dimension, the only associated factors were maternal education and non-indigenous background, we found that the prevalence of cognitive disability is associated with sex, maternal education, wealth and ethnic background. Children living in urban areas experienced a higher probability of socioemotional disability; this finding is interesting because previous studies on disability found an association with rural instead of urban areas.¹⁹ However, these studies focused on disabilities in general, which could be present in different contexts and it is not necessarily associated with rural/urban status.

Recently, functional difficulties and disabilities have been recognized as an important public health problem and a barrier to access fundamental rights. The 2030 Agenda for Sustainable Development and the United Nations Sustainable Developing Goals have been conceived with the clear mandate of leaving no one behind and explicitly mention the need to address the needs of people with disability. Identifying groups of the population at higher risk for SFD provides useful information for designing and monitoring the implementation of targeted interventions. The findings from our study show that a significant proportion of children experience SFD and require special attention to guarantee their full social participation; this challenge must become a primary concern of the newly created Integral System for Children and Adolescent Protection (SIPINNA), to ensure children with disabilities can exercise their human rights, increase their participation within our society, and to improve their quality of life.