Mobility Difficulty among Older Persons in India: Evidence from the National Sample Survey

Manisha Sengupta, Johns Hopkins University
Emily M. Agree, Johns Hopkins University

Despite an increasing wealth of research on mobility difficulty among older persons, relatively little is known about mobility difficulty among the elderly in South Asia, particularly India. Much of this lacuna in research can be attributed to the generally younger populations in these countries and the lack of surveys that are directed towards the elderly and their health concerns. However, a rapid rise during the last few decades and a further projected increase in the population of older adults in these countries has led to increased concern about their health and functional limitations. Recent evidence from India suggests a growing prevalence of morbidity and poor health status along with significant increases in longevity in the elderly population (Alam, 2000). Yet, barring a few exceptions, most studies about the health and functional ability of older persons in India are based on impressionistic findings and rarely provide empirical evidence addressing the factors that are associated with morbidity and functional limitations. Using a large nationally representative sample, this paper documents the prevalence of mobility difficulty among older persons in India and examines the factors associated with such difficulty. In this research, we seek to forward our understanding of mobility limitations among older persons in India based on theoretical considerations and our review of previous research focusing on developed country settings. We explore how different socio-economic, health and demographic variables are associated with mobility limitations in persons 60 years and older in India. With a rise in the population of older persons and an improvement in life expectancies, India is likely to experience an increase in functionally limited elders. It is therefore necessary to examine the covariates of functional limitations, particularly mobility difficulty, among older persons in India, and this current paper attempts to initiate such a dialogue. Although difficulty in physical functioning is more frequent with increasing age, studies have shown that older adults exhibit notably different functional ability and that not all persons in a particular age group experience similar health problems or are at the same level of functional capacity. There is evidence that sex and marital status are important correlates of health and functional status at older ages. Most of these studies confirm that women are more likely than men to suffer debilitating illnesses that cause functional impairment and disability (Penning & Strain, 1994; Verbrugge & Jette, 1994; Vebrugge & Wingard, 1987, Verbrugge, 1985, 1989; Merrill et al., 1997; Macintyre et al., 1999). Studies also show that marriage has a sizable protective effect on the mortality and morbidity of older adults, and this effect is more pronounced for men (Lillard & Waite, 1995; Hacker, 1997; Arens, 1982). One of the consistent findings from most previous studies is the positive association between socioeconomic status and health, particularly physical functioning (Camacho et al., 1993; Kaplan et al., 1993; Guralnik et al., 1993). In these studies, indicators of socioeconomic status encompass a variety of measures including education, occupation, income and ownership of household assets. An important finding from current epidemiologic research is the association between age, underlying disease and decline in functional capacity. There is now evidence to show that a majority of all physical disability in older adults results from chronic diseases with or without physiologic changes associated with aging (Fried et al., 1994; WHO, 1980; Verbrugge, 1990). The data used for this study come from the 42nd Round of the National Sample Survey of India (NSS) conducted by the National Sample Survey Organization (NSSO), which is a part of the Department of Statistics, Ministry of Planning and Programme Implementation, Government of India. This nationally representative survey (42nd round of the NSS) was the first survey conducted by the NSSO to assess the nature and dimensions of the socio-economic and health problems of the persons 60 years or older. The data include a wide variety of information including demographic and health status data as well as information on mobility restrictions. In addition to questions about socio-economic and demographic factors, this survey included questions on disability and chronic diseases. The questions that determine the extent of mobility restrictions are different from those used in surveys in the US and are not aligned with the ADL-IADL type questions used in western surveys. Respondents were first asked if they were physically immobile. Responses were coded either “yes” or “no”. Each respondent who reported being mobile was subsequent asked whether they had any mobility restrictions. Respondents who stated having some mobility restrictions were asked to select a reason for their mobility difficulty. Response categories included “health”, “financial”, “loss of contact” and “others”. Only those respondents who stated that their mobility restriction was related to health reasons were considered as having “some mobility difficulty” for the purposes of this analysis. Respondents who stated that the reason for their mobility difficulty was not health related was considered as having no mobility difficulty. The dependent variable for this analysis is a 3-category variable indicating that the respondent was (a) physically immobile, (b) had some mobility difficulty, or (c) had no mobility difficulty. We use multinomial logistic regression to model the 3-category mobility variable. Although the 3-category dependent variable would seem a candidate for ordered logistic regression and could be treated as an ordered response variable, the parallel lines assumption was not met by the model. To test for the parallel lines assumption, we used the score test for equal slopes in SAS software and given the weakness of in this assumption, we reverted to the use of a multinomial logistic regression model. While 7.2 and 5.4 percent of older women are immobile and have some mobility difficulty respectively, fewer men are immobile (4.8 percent) and have mobility difficulty (4.9 percent). These gender differences in mobility difficulty are statistically significant. Based on theoretical considerations and our review of previous research largely in developed countries, we selected a set of independent variables indicating health, demographic and socioeconomic characteristics of the respondents. Age, sex and marital status are entered into the model to indicate the demographic characteristics of the respondents. The mean age of the sample is about 67 years. Out of the 58,206 respondents, about 60 percent were men and 40 percent women. Results from our study confirm that women experience a disadvantage with respect to severe mobility restriction that can lead to immobility. Our results also confirm previous research regarding the negative association between marriage and mobility limitation. However, there were no significant gender differences in the association between marital status and mobility status among older persons in India. Considering, the level of son preference and cultural dependence on sons especially at older ages, it is not surprising that having more sons is associated with no or fewer mobility restrictions. Our analysis suggests that the mobility impact of prevalent chronic diseases in the elderly is substantial. A constellation of chronic diseases including diabetes, arthritis, heart disease, hypertension, and chronic cough can be risk factors for subsequent mobility difficulty. Another related and interesting finding is the association between non-diagnosis of certain chronic diseases and mobility restrictions. It is worth noting that this association may actually reflect the disjoint between health care utilization and risk of disability among the elderly. This finding underscores the existence of a group of older persons who do not avail of health care for whatever reason although they are at a very high risk of functional decline leading to mobility limitations. This study has important policy implications. First, these results suggest the need for a primary prevention strategy that will advocate lifestyle changes during middle ages in order to subsequently decrease the incidence or at least severity of chronic diseases that are associated with aging on the one hand and mobility restrictions on the other. 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