Abstract

The study of the association of social variables with the prevalence of impairments can provide subsidies for more adequate care and health policies for the most needy people by incorporating social aspects. This article aims to estimate the prevalence of diverse types of impairments, the degree of difficulty, limitations, and the need for help they cause and attest whether this prevalence differ by educational attainment in individuals aged 20 years or older. This is a populational cross-sectional study (2015 Health Survey of São Paulo-ISA Capital). Data from 3184 individuals were analyzed via educational attainment as exposure variable and outcome variables related to visual, hearing, intellectual, and mobility impairments. 19.9% of participants had visual, 7.8%, hearing, 2.7%, intellectual, and 7.4%, mobility impairments. Mobility and intellectual impairments limited participants’ daily activities the most, 70.3% and 63.3%, respectively; who, thus, needed the most help: 48.9% and 48.5%, respectively. Lower schooling was associated with a higher prevalence of impairments, greater need for help due to visual and intellectual impairments, and greater limitations due to hearing and visual impairments.

Key words:
Health surveys; Low vision; Hearing loss; Mobility limitation; Intellectual disability

Resumo

O estudo da associação de variáveis ​​sociais com a prevalência de deficiências pode fornecer subsídios para uma atenção e políticas de saúde mais adequadas às pessoas mais carentes ao incorporar aspectos sociais. O objetivo deste artigo é estimar a prevalência de diversos tipos de deficiências, o grau de dificuldade, as limitações e a necessidade de ajuda e verificar se essa prevalência difere por escolaridade em indivíduos com 20 anos ou mais. Trata-se de um estudo transversal populacional (Inquérito de Saúde de São Paulo 2015 - ISA-Capital). Os dados de 3.184 indivíduos foram analisados ​​com a escolaridade como variável de exposição relacionada às deficiências visuais, auditivas, intelectuais e de mobilidade. Dezenove vírgula nove por cento dos participantes apresentavam deficiência visual, 7,8% auditiva, 2,7% intelectual e 7,4% de mobilidade. Mobilidade e deficiência intelectual foram as que mais limitaram as atividades diárias, 70,3% e 63,3%, respectivamente, sendo, portanto, as que mais necessitaram de ajuda: 48,9% e 48,5%, respectivamente. Menor nível de escolaridade mostrou associação com maior prevalência de deficiências, maior necessidade de ajuda por deficiência visual e intelectual e maiores limitações por deficiência auditiva e visual.

Palavras-chave:
Inquéritos epidemiológicos; Baixa visão; Perda auditiva; Limitação de mobilidade; Deficiência intelectual

Introduction

The second article of the Brazilian Law for the Inclusion of Persons with Disabilities (Law no. 13.146/2015)¹1 Brasil. Presidência da República. Lei 13.146, de 6 de julho de 2015. Institui a Lei Brasileira de Inclusão da Pessoa com Deficiência (Estatuto da Pessoa com Deficiência). Diário Oficial da União 2015; 7 jul. establishes that ‘persons with disabilities are those who have long-term physical, mental, intellectual or sensory impairments, which in interaction with one or more barriers, may obstruct the full and effective participation of these persons in society on equal terms with others’; emphasizing the environmental influence on the lives of the persons with disabilities and the possible limitations to their full participation in society, aiming to ensure and promote their fundamental rights, freedoms, the social inclusion, and citizenship. These goals assume the structuring of public policies aimed at equalizing opportunities, contributing to reduce or eliminate the inequalities faced by the persons with disabilities²2 Brasil. Convenção sobre os direitos das pessoas com deficiência e de seu protocolo facultativo. Brasília [Internet]. 2009. [acessado 2023 ago 3]. Disponível em: http://www2.senado.leg.br/bdsf/bitstream/handle/id/99423/Convencao_direito_pessoas_deficiencia_2008.pdf?sequence=2
http://www2.senado.leg.br/bdsf/bitstream... ^,33 World Health Organization (WHO). World report on disability 2011. Geneva: WHO; 2011..

The literature has shown associations⁴4 Lauer EA, Houtenville AJ. Estimates of prevalence, demographic characteristics and social factors among people with disabilities in the USA: a cross-survey comparison. BMJ Open 2018; 8(2):e017828. and causal links⁵5 Dugravot A, Fayosse A, Dumurgier J, Bouillon K, Rayana TB, Schnitzler A, Kivimaki M, Sabia S, Singh-Manoux A. Social inequalities in multimorbidity, frailty, disability, and transitions to mortality: a 24-year follow-up of the Whitehall II cohort study. Lancet Public Health 2020; 5(1):e42-e50. between socioeconomic strata and disability prevalence, increasing in less developed countries, according to The World Report on Disability (WRD) of the World Health Organization (WHO)³3 World Health Organization (WHO). World report on disability 2011. Geneva: WHO; 2011.. A 2017 literature review of studies conducted in middle- and low-income countries reinforces this association⁶6 Banks LM, Kuper H, Polack S. Poverty and disability in low-And middleincome countries: a systematic review. PLoS One 2017; 12(12):e0189996., showing strong evidence between disabilities and poverty in 81% of the studies analyzed (122/150), with a statistically significant and direct association between these variables; comparatively, poorer countries show a higher disability prevalence than richer countries; a perverse cycle hindering the economic development of these countries and requiring the implementation of public policies to reverse this situation.

Note that, in addition to periodically estimating the prevalence of disabilities and impairments due to their impact on health systems and on people’s lives, we must also monitor the social inequalities prevalent in the occurrence and characteristics of these disabilities and impairments, for social and economic circumstances may enable countries to overcome the barriers to equalizing the conditions for a full life. Moreover, the demographic transition due to the greater proportion of older adults increases the impaired population, requiring public policies that contribute to reducing the possible repercussions these impairments cause on the quality of life of this age group. In view of the magnitude of the socioeconomic inequalities in the city of São Paulo causing about 85% of its population to live in socially excluded areas⁷7 Sposati A, Monteiro M. Desigualdades nos territórios da cidade: métricas sociais intraurbanas em São Paulo. São Paulo: EDUC; 2017., the prevalence of impairments according to socioeconomic strata is a central issue. The present research fills a gap in the literature by collecting prevalence data at the population level from the perspective of social inequalities, since other studies with this objective in the same city are not verified in the current literature.

Thus, we aimed to estimate the prevalence of diverse types of impairments, the degree of difficulty, limitations, and the need for help they cause, and attest whether this prevalence differs according to educational attainment in individuals aged 20 years or older living in the city of São Paulo in 2015.

Methods

Design and population

This is a cross-sectional, population-based study elaborated with data from the 2015 Health Survey of São Paulo (ISA-Capital). In total, 4,043 individuals aged 12 years or older living outside care institutions in the urban area of São Paulo were interviewed. Data from adults aged 20 years of age or above were analyzed. Access to the data is not open and is controlled by the consortium of researchers and the municipal health department of São Paulo.

Based on the 2015 ISA-Capital, our sample is probabilistic, stratified, and was taken in two stages. In its first stage, 150 census tracts were randomly chosen by a probability proportional to the number of households. In its second stage, households were drawn from the selected census tracts. Independently drawn, our sample domains were composed of adults of all genders aged from 12 to 19 years, 20 to 59 years, and ≥ 60 years. A minimum sample size of 4250 individuals was estimated to obtain 50% proportions (the maximum variability of the sample), with a 10% sampling error, and a 95% confidence level, considering a 1.5 design effect. The sampling plan used has already been published⁸8 Alves MCGP, Escuder MML, Goldbaum M, Barros MBA, Fisberg RM. Sampling plan in health surveys, city of São Paulo, Brazil, 2015. Rev Saude Publica. 2018; 52:81..

Variables

Our outcome variables were:

These questions could be answered thus: (1) Yes, I cannot at all; (2) Yes, I have a big difficulty; (3) Yes, I have some difficulty; and (4) No, no difficulty. Options 1, 2, and 3 were joined to form the category “Yes, shows impairment”.

Our exposure variables for visual, hearing, and mobility impairments were participants’ and heads of families’ (for intellectual impairment) educational attainment in completed years, split into 0 to 7 years, and 8 years or more.

The following variables were used to describe the studied population and some of them to access association with schooling to justify the use of this indicator as proxy of socioeconomic level: age group (20 to 39 years, 40 to 59, and 60 and above); gender; self-reported ethnicity (white, black or mixed - information of indigenous and other race were not showed and were excluded of this analysis, specifically, due to the low number of observations in this population); health insurance (yes/no); family income per capita in quartiles (1, 2, 3, and 4); and number of impairments (0, 1, 2, 3 or more).. Variables with missing data due to non-response were schooling (n = 18), income and number of impairments.

Data analysis

Associations were evaluated by the Rao-Scott chi-square test.

Prevalence, the 95% confidence intervals (95%CI), the percentage of limitations to daily activities, and the need for help with routine activities were estimated according to educational attainment. The prevalence ratios (PR) and 95%CI of each outcome variable were also estimated according to education attainment. Poisson regression models with robust variances were performed with adjustment for gender and age, variables known to have an influence on the prevalence of impairments⁴4 Lauer EA, Houtenville AJ. Estimates of prevalence, demographic characteristics and social factors among people with disabilities in the USA: a cross-survey comparison. BMJ Open 2018; 8(2):e017828. considering a statistical level of 5%. For the inferential analyzes regarding the differences between education, the models used the category of eight years or more of education as a reference. In addition, it is noteworthy that for the analysis of data on people with intellectual impairment, the level of education of the head of the family was used because low education is recorded among people with the impairment studied.

The design weight from the sampling process and the weight of non-response and post-stratification were considered in all analyses. They were conducted in STATA 15.0 svy module. This ISA-Capital project was approved by the Research Ethics Committee of the Faculdade de Saúde Pública FSP - USP, under no. 719.661/2014.

Results

Table 1 shows the socioeconomic and demographic characteristics, and the number of impairments of our sample according to educational attainment. In total, 46.2% of participants were adults under 40 years, 43.5%, black and mixed, 56.5%, lacked private health insurance, 7.5%, lived in precarious houses, and 28.4%, showed one or more impairments. We observed that educational strata showed significant differences in all variables studied, except gender. The less educated show a significantly higher proportion of older, self-reported black and mixed adults with more impairments and lower incomes who lack health insurance and live in precarious homes (Table 1).

Visual impairments were the most prevalent in our group (19.9%), followed by hearing (7.8%) and mobility ones (7.4%), whereas intellectual impairment, the least prevalent (2.7%). Mobility and intellectual impairments hinder work, school or leisure the most, reaching, 70% and 63%, respectively. About half of these participants reported needing help with routine activities (Table 2).

Visual, hearing, and mobility impairments unevenly affect the population, with a significantly higher prevalence (30 to 44%) among the less educated. Due to their small number, we failed to find statistically significant differences among the intellectually impaired according to heads of families’ educational attainment. The intellectually and visually impaired showed a need for help with routine activities 5.6 and 3.1 times more prevalent than the more educated, respectively (Table 3).

Comparing both educational groups shows a statistically significant difference in visual impairments, higher in the less (total difficulty: 3.0%; big difficulty: 15.6%) than in the more educated (total difficulty: 0.7%; big difficulty: 9.4%). Though we failed to observe a statistically significant difference between educational strata for mobility impairments, we noted a higher prevalence among the less educated, both for those with big (24.7% x 17.5%), and total difficulty (4.3% x 2.4%) (Table 4).

Discussion

Our results show that visual impairment is the most prevalent of the four impairments studied, and that intellectual and mobility impairments cause the most intense limitations and need for help. They also indicate that the less educated show a higher prevalence of all impairments, needing more help with daily activities if visually or intellectually impaired, in which the former suffers with bigger difficulty.

Impairment prevalence

Our comparison of the prevalence of visual impairment in this study with the literature required consideration of data collection strategies. We asked participants to wear optical aids when assessing their disabilities, and 19.9% of our sample self-reported such impairment. However, if we had considered only those with ‘total or big difficulty to see’, we would have found a 2.9% prevalence. Thus, the prevalence of more severe visual impairments (low vision and blindness) would be a more appropriate comparison with other studies which used clinical tests following WHO evaluation parameters rather than self-reported data. A 2013 systematic review used data from several countries over the last 20 years, finding a visual impairment prevalence of about 3.3%⁹9 Stevens GA, White RA, Flaxman SR, Price H, Jonas JB, Keeffe J, Leasher J, Naidoo K, Pesudovs K, Resnikoff S, Taylor H, Bourne RRA; Vision Loss Expert Group. Global prevalence of vision impairment and blindness: Magnitude and temporal trends, 1990-2010. Ophthalmology 2013; 120(12):2377-2384., whereas a 2015 study conducted in China found a 6.1% prevalence¹⁰10 Tang Y, Wang X, Wang J, Huang W, Gao Y, Luo Y, Lu Y. Prevalence and causes of visual impairment in a Chinese adult population: the Taizhou Eye Study. Ophthalmology 2015; 122(7):1480-1488.. On the other hand, a Brazilian study evaluating blindness and low vision used data from the 2013 National Health Survey (PNS) and self-reported data, finding a 3.6% prevalence¹¹11 Malta DC, Stopa SR, Canuto R, Gomes NL, Mendes VL, Goulart BN, Moura L. Self-reported prevalence of disability in Brazil, according to the National Health Survey, 2013. Cien Saude Colet 2016; 21(10):3253-3264.. The lower prevalence of more severe visual impairment in São Paulo, when compared to Brazil, may be due to several factors, such as greater access to health services, corrective devices (glasses, lenses, etc.), and better socioeconomic indices.

We found a 7.8% prevalence of hearing impairment. Emphasizing its importance as a global health problem¹²12 Lancet T. Hearing loss: an important global health concern. Lancet 2016; 387(10036):2351., the WHO estimated its global prevalence to be 5.3% in 2012, and the literature, assorted values. A 2020 study estimated a 15.6% global prevalence of this impairment via a digital application. Pakistan (37.8%), Bangladesh (32.2%), and India (28.5%) ranked highest, and Taiwan (9.6%), Finland (9.8%), and South Korea (10.2%), the lowest. Brazil showed a 14.2% prevalence¹³13 Masalski M, Morawski K. Worldwide prevalence of hearing loss among smartphone users: cross-sectional study using a mobile-based app. J Med Internet Res 2020; 22(7):e17238.. Another study analyzed four locations in the state of São Paulo and found a 5.2% prevalence¹⁴14 Cruz MS, Oliveira LR, Carandina L, Lima MC, César CL, Barros MB, Alves MC, Goldbaum M. Prevalência de deficiência auditiva referida e causas atribuídas: um estudo de base populacional. Cad Saude Publica 2009; 25(5):1123-1131.. The variations verified for this prevalence may originate from the lack of standardization of the collection process, greater exposure to environmental noise, older age, and iatrogenic factors. But the important thing to highlight is that the city now has reliable data for the generation of health indicators and subsequent implementation of public policies in this field.

In our study, 7% of the interviewees reported mobility impairments. Data collected by telephone during the 2016 US Behavioral Risk Factor Surveillance System (BRFSS) used the same questions as us and showed a 13.7% overall prevalence among adults in USA¹⁵15 Okoro CA, Hollis ND, Cyrus AC, Griffin-Blake S. Prevalence of disabilities and health care access by disability status and type among adults - United States, 2016. MMWR Morb Mortal Wkly Rep 2018; 67(32):882-887.. Another study used the Survey of Income and Program Participation - SIPP and found that 10.4% of the adults interviewed struggled with walking three blocks in this same country¹⁶16 Theis KA, Steinweg A, Helmick CG, Courtney-Long E, Bolen JA, Lee R. Which one? What kind? How many? Types, causes, and prevalence of disability among U.S. adults. Disabil Health J 2019; 12(3):411-421.. A 2014 study conducted in India asked if interviewees struggled, even with assistive devices, to walk around their homes in the previous six months, finding a 4.7% impairment prevalence¹⁷17 Ramachandra SS, Allagh KP, Kumar H, Grills N, Marella M, Pant H, Mahesh D, Soji F, Mani S, Murthy GV. Prevalence of disability among adults using Rapid Assessment of Disability tool in a rural district of South India. Disabil Health J 2016; 9(4):624-631.. Despite these outcomes, identical collection strategies may vary due to population, cultural, and environmental sample characteristics. Therefore, it is clear that for the effective implementation of policies to improve this prevalence, factors such as environment and culture must also be considered.

We found a 2.7% prevalence of intellectual impairment. A study using 2013 PNS data found a 0.8% prevalence of intellectual impairment in Brazil¹¹11 Malta DC, Stopa SR, Canuto R, Gomes NL, Mendes VL, Goulart BN, Moura L. Self-reported prevalence of disability in Brazil, according to the National Health Survey, 2013. Cien Saude Colet 2016; 21(10):3253-3264.. The findings of a study from USA ranged from 0.52 to 0.79% among adults in 1995¹⁸18 Anderson LL, Larson SA, Lentz SM, Hall-Lande J. A systematic review of U.S. studies on the prevalence of intellectual or developmental disabilities since 2000. Intellect Dev Disabil 2019; 57(5):421-438.. The scarcity of studies dealing with the subject makes it difficult to compare data across studies.

The use of comparable questions by these studies would have facilitated the comparison of populations and demographic subgroups.

Comparing the prevalence of the impairments analyzed with the literature was a complex task due to factors such as: a) different definitions of ‘impairment’, b) distinct data collection strategies (self-reported versus clinical tests or digital applications); and c) differently-aged samples influence outcomes since some impairments intensify with age; making it difficult to compare the real differences in the prevalence obtained in the studies analyzed. Therefore, we must consider these aspects when interpreting the findings and we hope specialists make recommendations for future studies toward overcoming them.

Inequalities in the prevalence of impairments and the limitations they cause

We found that impairments were more prevalent among the less educated, as did international studies. Studies conducted in the United Kingdom¹⁹19 Cumberland PM, Rahi JS. Visual function, social position, and health and life chances the UK Biobank study. JAMA Ophthalmol 2016; 134(9):959-966., China²⁰20 Zhao J, Ellwein LB, Cui H, Ge J, Guan H, Lv J, Ma X, Yin J, Yin ZQ, Yuan Y, Liu H. Prevalence of vision impairment in older adults in rural China. Ophthalmology 2010; 117(3):409-416., and Korea²¹21 Rim THT, Nam JS, Choi M, Lee SC, Lee CS. Prevalence and risk factors of visual impairment and blindness in Korea: The Fourth Korea National Health and Nutrition Examination Survey in 2008-2010. Acta Ophthalmol 2014; 92(4):317-325. report the relation between visual impairment and educational attainment; higher educational attainment related to a lower prevalence of visual impairment, in proportions of 99%, 30%, and 60%, respectively. Similarly, a study conducted in Mexico²²22 Jimenez-Corona A, Jimenez-Corona ME, Ponce-De-Leon S, Chavez-Rodriguez M, Graue-Hernandez EO. Social determinants and their impact on visual impairment in Southern Mexico. Ophthalmic Epidemiol 2015; 22(5):342-348. found a 130% greater prevalence among the illiterate than the literate. The higher prevalence of visual impairment among the less educated may be due to differences in the search for ophthalmologic care²³23 Burnett A, Yu M, Paudel P, Naduvilath T, Fricke TR, Hani Y, Garap J. Perceptions of eye health and eye health services among adults attending outreach eye care clinics in Papua New Guinea. Ophthalmic Epidemiol 2015; 22(6):361-369., perhaps deriving from lower income or a poorer understanding of the need for care. The less educated may also show a worse behavior toward eye health throughout their lives²⁴24 Zhao M, Gillani AH, Islam FMA, Ji W, Hayat K, Li Z, Akbar J, Ahmed AB, Azam A, Masood I, Fang Y. Factors associated with knowledge, attitude and practices of common eye diseases in general population: a multicenter cross-sectional study from Pakistan. Int J Environ Res Public Health 2019; 16(9):1568..

Studies show the same trend for hearing impairment. The National Health and Nutrition Examination Survey (NHANES), conducted in the USA, found a 320% greater chance of that impairment among the less educated²⁵25 Hoffman HJ, Dobie RA, Losonczy KG, Themann CL, Flamme GA. Declining prevalence of hearing loss in US adults aged 20 to 69 years. JAMA Otolaryngol Head Neck Surg 2017; 143(3):274., as did the English Longitudinal Study of Ageing (ELSA), in which less educated men and women showed an 87% and 138% higher prevalence for that impairment²⁶26 Tsimpida D, Kontopantelis E, Ashcroft D, Panagioti M. Socioeconomic and lifestyle factors associated with hearing loss in older adults: a cross-sectional study of the English Longitudinal Study of Ageing (ELSA). BMJ Open 2019; 9(9):e031030.. A 2003 survey conducted in Brazil showed that the less educated are 292% more likely to suffer from hearing impairments than the more educated²⁷27 Béria JU, Raymann BCW, Gigante LP, Figueiredo AC, Jotz G, Roithman R, Selaimen da Costa S, Garcez V, Scherer C, Smith A. Hearing impairment and socioeconomic factors: A population-based survey of an urban locality in southern Brazil. Rev Panam Salud Publica 2007; 21(6):381-387.. Greater exposure to excessive noise while working²⁸28 Engdahl B, Tambs K. Occupation and the risk of hearing impairment - results from the Nord-Trøndelag study on hearing loss. Scand J Work Environ Health 2010; 36(3):250-257.; lower hearing screening in families²⁹29 Chen PH, Lim TZ. Newborn hearing screening and early auditory-based treatment in Taiwan: action trends of families with children who are hearing impaired. Int J Audiol 2020; 60(7):514-520.; lower adequate use of assistive devices; and less knowledge about specific programs for hearing health³⁰30 Fuentes-López E, Fuente A, Cardemil F, Valdivia G, Albala C. Prevalence and associated factors of hearing aid use among older adults in Chile. Int J Audiol 2017; 56(11):810-818. among the less educated could explain this inverse association.

Educational attainment also showed an inverse relation to mobility impairment, perhaps due to unfavorable environmental characteristics³¹31 Wijk DC, Groeniger JO, Lenthe FJ, Kamphuis CBM. The role of the built environment in explaining educational inequalities in walking and cycling among adults in the Netherlands. Int J Health Geogr 2017; 16(1):10.; greater access to assistive walking devices among the more educated³²32 van der Esch M, Heijmans M, Dekker J. Factors contributing to possession and use of walking AIDS among persons with rheumatoid arthritis and osteoarthritis. Arthritis Care Res (Hoboken) 2003; 49(6):838-842.; worse health, and lower frequency of walking as a physical activity among the less educated³³33 Eyler AA, Brownson RC, Bacak SJ, Housemann RA. The epidemiology of walking for physical activity in the United States. Med Sci Sports Exerc 2003; 35(9):1529-1536..

We found that heads of families’ lower educational attainment related to a greater need for help with routine activities, corroborating the literature³⁴34 Vilaseca R, Gràcia M, Beltran FS, Dalmau M, Alomar E, Adam-Alcocer AL, Simó-Pinatella D. Needs and supports of people with intellectual disability and their families in Catalonia. J Appl Res Intellect Disabil 2017; 30(1):33-46., perhaps due to poorer living conditions and care knowledge, greater struggle accessing services³⁵35 Hewitt A, Agosta J, Heller T, Williams AC, Reinke J. Families of individuals with intellectual and developmental disabilities: Policy, funding, services, and experiences. Intellect Dev Disabil 2013; 51(5):349-359.; lower mobility, and bigger difficulty with feeding, bathing, and dressing; among others³⁶36 Lin LP, Hsia YC, Hsu SW, Loh CH, Wu CL, Lin JD. Caregivers' reported functional limitations in activities of daily living among middle-aged adults with intellectual disabilities. Res Dev Disabil 2013; 34(12):4559-4564..

The literature attests to the overall higher prevalence of impairments in lower socioeconomic strata. A study conducted in 26 European countries showed a 15-year (2002 to 2017) increase in the unequal prevalence across socioeconomic strata³⁷37 Rubio Valverde JR, Mackenbach JP, Nusselder WJ. Trends in inequalities in disability in Europe between 2002 and 2017. J Epidemiol Community Health 2021; 75(8):712-720.. An European study with data from 15 countries showed an association between greater age, impairments, and lower educational attainment³⁸38 Nusselder WJ, Rubio Valverde J, Bopp M, Brønnum-Hansen H, Deboosere P, Kalediene R, Kovács K, Leinsalu M, Martikainen P, Menvielle G, Regidor E, Wojtyniak B, Mackenbach JP. Determinants of inequalities in years with disability: an international-comparative study. Eur J Public Health 2020; 31(3):527-533.. A study conducted in 15 European countries using the Global Activity Limitation Indicator (GALI) found the more educated to have a higher life expectancy without impairments³⁹39 Valverde JR, Mackenbach J, Bopp M, Brønnum-Hansen H, Deboosere P, Kalediene R, Kovács K, Leinsalu M, Martikainen P, Regidor E, Strand BH, Nusselder W. Determinants of educational inequalities in disability-free life expectancy between ages 35 and 80 in Europe. SSM Popul Health 2021; 13:100740.. Analyzing their cohort by questions on vision, hearing, cognition, and mobility impairments, a Dutch study conducted with 24,883 adults of all genders found that the less educated could show an impairment prevalence about 20% higher than the more educated⁴⁰40 Klijs B, Nusselder WJ, Looman CW, Mackenbach JP. Educational disparities in the burden of disability: contributions of disease prevalence and disabling impact. Am J Public Health 2014; 104(8):e141-e148..

An Australian study conducted with data from 2013 and 2014 with almost 16,000 males showed that impairments related to unemployment, budget restrictions, lower income, and poor and rented housing in socioeconomically excluded areas⁴¹41 Kavanagh AM, Aitken Z, Emerson E, Sahabandu S, Milner A, Bentley R, LaMontagne AD, Pirkis J, Studdert D. Inequalities in socio-economic characteristics and health and wellbeing of men with and without disabilities: a cross-sectional analysis of the baseline wave of the Australian Longitudinal Study on Male Health. BMC Public Health 2016; 16(Supp. 3):1042.. A study conducted in Brazil with data from the 2013 PNS showed that the prevalence of limitations due to chronic diseases and visual, hearing, intellectual or motor impairments was higher in less educated lower socioeconomic strata⁴²42 Boccolini PMM, Duarte CMR, Marcelino MA, Boccolini CS. Desigualdades sociais nas limitações causadas por doenças crônicas e deficiências no Brasil: Pesquisa Nacional de Saúde - 2013. Cien Saude Colet 2017; 22(11):3537-3546..

Studies often analyze the social inequalities in the prevalence of impairments by educational attainment; a social determinant of health. Its influence lies in the fact that it gives access to material and immaterial resources such as knowledge, skills, income, safety or healthy lifestyles, all protective factors to health. Moreover, the information is relevant throughout people’s lives, easy to collect, and usually shows low non-response rates⁴³43 Galobardes B. Indicators of socioeconomic position (part 1). J Epidemiol Community Health 2006; 60(1):7-12.. In view of the discussion developed in this study, it is clear, therefore, that for the design of policies to reduce impairments; its limitations and dependence on aid, policies that consider investment in improving the population’s educational level are important strategies that could be adopted.

One of the limitations of this study is the reliance on participants’ self-reports to assess the occurrence of impairments. Population studies have adopted different definitions of impairment and instruments over time. Thus, they have used the Washington Group on Disability Statistics (WG) and its five questions on vision, hearing, displacement, cognition, communication, and self-care⁴⁴44 Madans JH, Loeb M. Methods to improve international comparability of census and survey measures of disability. Disabil Rehabil 2013; 35(13):1070-1073.; the Global Activity Limitation Indicator (GALI) and its single question on the impairment of normal activities in the last six months⁴⁵45 Rubio-Valverde JR, Nusselder WJ, Mackenbach JP. Educational inequalities in Global Activity Limitation Indicator disability in 28 European Countries: Does the choice of survey matter? Int J Public Health 2019; 64(3):461-474.; and the WHO via the Model Disability Survey (MDS), designed to collect population data on disability. In addition to collecting data on visual, physical, hearing, mental, and intellectual disabilities, it also gathers data on diseases to assess the prevalence of mild, moderate or severe disabilities according to capacity and performance variables⁴⁶46 United Nations (UN). Model disability survey: providing evidence for accountability and decision-making [Internet]. 2015. [cited 2023 ago 3]. available from: http://www.who.int/disabilities/data/mds.pdf
http://www.who.int/disabilities/data/mds... . These dissonances in the literature may be due to relation of the construct ‘impairment’ with personal, environmental, and contextual factors⁴⁷47 Henning-Smith C, Shippee T, Capistrant B. Later-life disability in environmental context: why living arrangements matter. Gerontologist 2018; 58(5):853-862.. Discussing the results showed the need for standard indicators of the several types of impairments to facilitate comparisons between findings and ensure the greater accuracy of their results, as the literature has already suggested⁴⁸48 Sabariego C, Oberhauser C, Posarac A, Bickenbach J, Kostanjsek N, Chatterji S, Officer A, Coenen M, Chhan L, Cieza A. Measuring disability: comparing the impact of two data collection approaches on disability rates. Int J Environ Res Public Health 2015; 12(9):10329-10351.. The WHO Global Action Plan 2014-2021 aims to strengthen comparable data collection on disability among its member countries⁴⁹49 World Health Organization (WHO). WHO Global Disability Action Plan 2014-2021: Better Health for All People with Disability. Vol 2. Geneva: WHO; 2014..

The higher prevalence of impairments among the less educated in São Paulo alerts us to their poorer living and housing conditions, and lower access to health and rehabilitation services, hindering the care of impaired people. Thus, health policies aimed at the impaired should reinforce their focus on social health determinants, especially socioeconomic factors, such as educational attainment.

We should mention that this study is the result of a household-based survey conducted in the largest Brazilian city to be used in the municipal management of health services. In addition, it is worth highlighting as a strong point the fact that the survey’s sampling process guarantees internal and external validity, allowing to infer information with population representativeness for the city of São Paulo, the largest in Latin America.

Conclusion

The results of the present study showed that visual impairment was the most prevalent and intellectual impairment was the least prevalent among the participants. In addition, people with mobility difficulties were the ones who had the greatest difficulty, the most activity limitations, and the most need for help.

Our results show that the prevalence of impairments is significantly higher among the less educated, reinforcing the need for interventions, and intersectoral and health policies prioritizing the reduction of inequalities. They also highlight the need for evaluating current policies to expand the access to qualified care, and articulating and integrating health services (primary, specialized, and hospital care) and other national resources for the care of the population, especially of its most socially vulnerable segments. Standardizing data collection on disability and impairments is also a pressing objective in better comparing and monitoring the prevalence of disabilities to satisfactorily implement health and equity policies.

References

Publication Dates

History