Socioeconomic disparities in health change in a longitudinal study of US adults: the role of health-risk behaviors.

This study investigated the hypothesis that socioeconomic differences in health status change can largely be explained by the higher prevalence of individual health-risk behaviors among those of lower socioeconomic position. Data were from the Americans' Changing Lives study, a longitudinal survey of 3,617 adults representative of the US non-institutionalized population in 1986. The authors examined associations between income and education in 1986, and physical functioning and self-rated health in 1994, adjusted for baseline health status, using a multinomial logistic regression framework that considered mortality and survey nonresponse as competing risks. Covariates included age, sex, race, cigarette smoking, alcohol consumption, physical activity, and Body Mass Index. Both income and education were strong predictors of poor health outcomes. The four health-risk behaviors under study statistically explained only a modest portion of the socioeconomic differences in health at follow-up. For example, after adjustment for baseline health status, those in the lowest income group at baseline had odds of moderate/severe functional impairment in 1994 of 2.11 (95% C.I.: 1.40, 3.20) in an unadjusted model and 1.89 (95% C.I.: 1.23, 2.89) in a model adjusted for health-risk behaviors. The results suggest that the higher prevalence of major health-risk behaviors among those in lower socioeconomic strata is not the dominant mediating mechanism that can explain socioeconomic disparities in health status among US adults.

Excess mortality among urban residents: how much, for whom, and why?

OBJECTIVES: The goals of this study were to estimate prospective mortality risks of city residence, specify how these risks vary by population subgroup, and explore possible explanations. METHODS: Data were derived from a probability sample of 3617 adults in the coterminous United States and analyzed via cross-tabular and Cox proportional hazards methods. RESULTS: After adjustment for baseline sociodemographic and health variables, city residents had a mortality hazard rate ratio of 1.62 (95% confidence interval [CI] = 1.21, 2.18) relative to rural/small-town residents; suburbanites had an intermediate but not significantly elevated hazard rate ratio. This urban mortality risk was significant among men (hazard rate ratio: 2.25), especially non-Black men, but not among women. Among Black men, and to some degree Black women, suburban residence carried the greatest risk. All risks were most evident for those younger than 65 years. CONCLUSIONS: The mortality risk of city residence, at least among men, rivals that of major psychosocial risk factors such as race, low income, smoking, and social isolation and merits comparable attention in research and policy.

Socioeconomic factors, health behaviors, and mortality: results from a nationally representative prospective study of US adults.

CONTEXT: A prominent hypothesis regarding social inequalities in mortality is that the elevated risk among the socioeconomically disadvantaged is largely due to the higher prevalence of health risk behaviors among those with lower levels of education and income. OBJECTIVE: To investigate the degree to which 4 behavioral risk factors (cigarette smoking, alcohol drinking, sedentary lifestyle, and relative body weight) explain the observed association between socioeconomic characteristics and all-cause mortality. DESIGN: Longitudinal survey study investigating the impact of education, income, and health behaviors on the risk of dying within the next 7.5 years. PARTICIPANTS: A nationally representative sample of 3617 adult women and men participating in the Americans' Changing Lives survey. MAIN OUTCOME MEASURE: All-cause mortality verified through the National Death Index and death certificate reviews. RESULTS: Educational differences in mortality were explained in full by the strong association between education and income. Controlling for age, sex, race, urbanicity, and education, the hazard rate ratio of mortality was 3.22 (95% confidence interval [CI], 2.01-5.16) for those in the lowest-income group and 2.34 (95% CI, 1.49-3.67) for those in the middle-income group. When health risk behaviors were considered, the risk of dying was still significantly elevated for the lowest-income group (hazard rate ratio, 2.77; 95% CI, 1.74-4.42) and the middle-income group (hazard rate ratio, 2.14; 95% CI, 1.38-3.25). CONCLUSION: Although reducing the prevalence of health risk behaviors in low-income populations is an important public health goal, socioeconomic differences in mortality are due to a wider array of factors and, therefore, would persist even with improved health behaviors among the disadvantaged.

Depression in black and white women. The role of marriage and socioeconomic status.

The degree to which the relationship between race and depression in US black and white women is modified by socioeconomic and marital status was investigated. Data on 534 black and 836 white women, 25 to 64 years old, obtained from the 1986 Americans' Changing Lives national survey were utilized. Depression was measured by the Centers for Epidemiologic Studies Depression scale. Poverty status and education were used as indicators of socioeconomic status (SES). For both black and white women, the prevalence of depression was higher among those with lower as compared to higher SES, and among the unmarried as compared to the married. The unstratified, age-adjusted odds of depression for black women was twice that for white women (odds ratio (OR) = 2.2; 95% confidence interval (CI), 1.7 to 2.8); however, when stratified by poverty status, race effects were observed for nonpoor (OR = 2.2; 95% CI, 1.6 to 3.0) but not for poor women (OR = 1.3; 95% CI, 0.7 to 2.1). Race effects were also more pronounced among married (OR = 2.0; 95% CI, 1.4 to 2.9) than unmarried women (OR = 1.6; 95% CI, 1.1 to 2.4). Controlling for known confounders did not alter these results. Additional analyses revealed that the black excess risk for depression was concentrated among higher SES, married women, with marital difficulties appearing to pay a major role in their elevated depression scores.

The social stratification of aging and health.

The way health varies with age is importantly stratified by socioeconomic status (SES)--specifically, education and income. Prior theory and cross-sectional data suggest that among higher SES persons the onset of health problems is usually postponed until rather late in life, while health declines are prevalent in lower SES groups by middle age. Thus, SES differences in health are small in early adulthood, but increase with age until relatively late in life, when they diminish due to selection or greater equalization of health risks and protections. The present paper strengthens our causal and interpretive understanding of these phenomena by showing: (1) that results previously reported for indices of SES hold separately for education and income; (2) that the interaction between age and SES (i.e., education or income) in predicting health can be substantially explained by the greater exposure of lower SES persons to a wide range of psychosocial risk factors to health, especially in middle and early old age, and, to a lesser degree, the greater impact of these risk factors on health with age; and (3) that results (1) and (2) generally hold in short-term longitudinal as well as in cross-sectional data. Implications for science and policy in the areas of aging, health, and social stratification are discussed.

The cost effectiveness of strategies to reduce barriers to cataract surgery. The Operations Research Group.

The cost and effectiveness of eight approaches to reducing barriers to cataract surgery were evaluated in a rural area of South India during 1987-1989. The approaches were based on four intervention alternatives--aphakic motivator (AM), basic eye health worker (BW), screening van (SV), and mass media (MM). Each intervention was offered at two levels of economic incentive: partial, which provides free surgery and hospital stay, and full, which also provides transport from the recipient's village to the hospital and free food during the hospital stay. Evaluations took place in a probability selection of 90 villages, including ten control villages not subjected to either of the interventions. Only costs unique to patients from the intervention villages were considered: Health education and screening costs were included, surgery costs were not. Percentage reductions in the cataract blind backlog and increases in surgical coverage were used as effectiveness measures. Analyses suggest that the SV and AM interventions, both with full economic incentive, offer the greatest advantage. The AM intervention is the more effective of the two, but also the more costly.

Social determinants of cataract surgery utilization in south India. The Operations Research Group.

A field trial was conducted to compare the effects of eight health education and economic incentive interventions on the awareness and acceptance of cataract surgery. Cataract screening and follow-up surgery were offered to more than 19,000 residents age 40 years and older in a probability sample of 90 villages in south India. Eight months after intervention, an evaluation was conducted to identify those in need of surgery who had been operated on. Two principal measures of program effectiveness are examined: awareness of cataract surgery and acceptance of the surgery. The type of intervention had a negligible effect on awareness of cataract surgery. A multiple logistic regression analysis revealed that individuals who were aware of surgery tended to be male, literate, and more affluent than those who were unaware of that option. Interventions that covered the complete costs of surgery had higher surgery acceptance rates. One health education strategy, house-to-house visits by a subject with aphakia, increased acceptance of the procedure more than others. In a multiple logistic regression analysis of acceptance rates, persons accepting surgery tended to be male; other factors were not important in explaining variation in acceptance rates.

Sampling the difficult-to-sample.

Difficult-to-sample populations are defined as rare populations or populations that are difficult to locate, enumerate or interview. This definition includes subgroups of the United States population that are at increased risk of adverse health effects associated with malnutrition. Examples include persons who are rare (pregnant women), difficult to locate (migrant farm workers), difficult to enumerate (homeless individuals) or difficult to interview (substance abusers). Probability methods to sample rare and elusive populations are reviewed briefly. Methods include disproportionately allocated sampling, multiplicity sampling and the use of multiple frames. The advantages and disadvantages of nonprobability sampling methods are compared using criteria typically applied to assess alternative probability sampling methods. The cost of data collection alone may prohibit consideration of probability sampling methods, but caution is urged before abandoning this statistically sound approach to sample selection. Considerations for sampling the difficult-to-sample are illustrated for one such population, the homeless.

Levels of disability among U.S. adults with arthritis.

This article studies the excess levels of disability experienced by persons with arthritis, compared to persons without the disease. The data set is the Supplement on Aging (1984 National Health Interview Survey); it has information for a national probability sample of community-dwelling persons ages 55 + (N = 16,148). (1) Arthritis people have more difficulty in physical functions, personal care, and household care than do nonarthritis persons. The excess disability is greatest for physical functions (walking, reaching, stooping, etc.). Disabled arthritis people have especially high degrees of difficulty in physical activities that require endurance and strength. (2) Various models are tested for walking, grasping, shopping, and light housework to show how comorbidity propels disability for arthritis people and to show arthritis' own contribution to disability in the presence of other chronic conditions. Difficulties escalate for arthritis people when they have other concurrent conditions. These models affirm that arthritis has a pronounced effect on physical dysfunctions, but these are not readily translated into personal and household care problems. Apparently, arthritis people often make successful accommodations so their roles and daily activities are not seriously affected by the disease.

Health care utilization and costs of adult cardiovascular conditions United States, 1980.

Cardiovascular conditions have a major economic as well as health impact on adults in the United States. In the National Medical Care Utilization and Expenditure Survey, conducted during 1980, health service data were obtained from a national sample of 17,123 civilian noninstitutionalized individuals. These data have been analyzed to define the impact and demographic patterns of health care utilization and costs attributable to adult cardiovascular conditions. Approximately 28 million persons in the United States, or 17.3 percent of the total civilian noninstitutionalized population 17 years of age and over, had a cardiovascular condition during 1980. Cardiovascular conditions were reported with increasing frequency in successively older age groups and were reported most frequently by black persons. The prevalence and economic impact differed by specific type of cardiovascular condition and whether the condition was complicated by another disease. To examine these differences, persons reporting cardiovascular conditions were categorized into four mutually exclusive groups: persons with hypertension alone, persons with arteriosclerotic cardiovascular and cerebrovascular disease associated with hypertension, persons with arteriosclerotic cardiovascular disease alone, and persons with cardiovascular disease associated with other conditions that might alter medical care utilization and disability. The disability, service utilization, and health care charges were compared among these groups, and data for each group were compared with those for the overall U.S. population. Survey participants were asked to rate their health relative to that of other people their age. The self-rating of persons reporting hypertension alone was lower than the national average. Only 17 percent of the general population rated their health as "fair" or "poor," but 27 percent of persons with hypertension alone used these descriptions. Overall, persons with hypertension alone were much less likely to be employed than the general population (52.2 percent versus 71.6 percent). However, when controlling for age, it was found that persons with hypertension alone were about as likely to be employed as the general population. On the average, persons with hypertension reported only slightly more work-loss days than did the general population (6.5 versus 4.9 days). A modest restriction of activity was reported by those with hypertension alone (20.1 days per year on the average compared with 15.6 for the general population). The mean number of ambulatory visits per year for those with hypertension alone was 7.9, only slightly greater than the 5.7 average for the overall population.(ABSTRACT TRUNCATED AT 400 WORDS)

Comorbidity and its impact on disability.

Older people often suffer from comorbidity, or several chronic conditions simultaneously. Disability rises rapidly as the number of chronic conditions grows, although very ill people who acquire another condition experience attenuated increases. High prevalence conditions such as arthritis tend to have a low or occasionally moderate impact for community residents, while low prevalence ones such as osteoporosis have a high impact; paired conditions sometimes give extra propulsion to disability, as when cerebrovascular disease and hip fracture co-occur. Further research is needed to pin-point combinations of conditions posing great risks and to identify demographic segments in which comorbidity has elevated effects.

Rapid epidemiologic assessment of cataract blindness. The Aravind Rapid Epidemiologic Assessment Staff.

A major constraint to obtaining reliable information about blindness and its causes in developing countries is the limited availability of ophthalmologists for diagnosis in population-based surveys. This study in rural south India assessed the feasibility of using non-ophthalmologists to make diagnoses in a population-based survey. Ten men in their early twenties with 12 years of schooling were recruited and trained as ophthalmic assistants through a six week course in basic ophthalmology. All people aged 40 and older in households in 24 villages were enumerated and invited to have an eye examination. At a central site, 1309 subjects were independently examined by an ophthalmologist and two different ophthalmic assistants. Ophthalmic assistant cataract diagnosis is both sensitive and specific relative to the ophthalmologist's diagnosis. Sensitivity and specificity estimates were used to adjust prevalence estimates obtained from ophthalmic assistant examinations conducted at the central site as well as at the doorstep of sample households. The findings indicate that epidemiologic assessment of cataract blindness can be completed using non-ophthalmologists to diagnose cataract.

Strategies for the analysis of imputed data from a sample survey. The National Medical Care Utilization and Expenditure Survey.

Missing data in sample surveys is virtually unavoidable, whether it is an entire unit that is missing or only an item for a responding unit. Compensation for unit nonresponse is usually made through the assignments of weights to responding units; for item nonresponse, the compensation often is by an imputation procedure. This paper reviews the extent of missing data in a large federal survey, the National Medical Care Utilization and Expenditure Survey, and the imputation procedures used to compensate for item missing data. The effects of imputation on several types of estimates from the survey are examined. In addition, several methods for analyzing survey data with imputed values are reviewed, and recommendations about preferred strategies are made for selected circumstances.

Disability, utilization, and costs associated with musculoskeletal conditions.

In this report, data from the 1980 National Medical Care Utilization and Expenditure Survey are used to present health characteristics, types and quantities of services used, and the charges for these services for persons with musculoskeletal diseases. Slightly more than 44 million people, or 19.8 percent of the U.S. civilian noninstitutionalized population, were reported in the survey to have at least one musculoskeletal disorder. These data are generally consistent with those from other health surveys, which show that the prevalence of musculoskeletal disorders increases for successive age categories, that such disorders are more common among women than among men, and that they are less prevalent among black persons than among persons of other races. In terms of both functional limitation and perceived health status, persons with musculoskeletal conditions are, with some notable exceptions, in relatively poor health. Persons having back problems in addition to problems with peripheral joints (such as the knee, hip, or shoulder) were more likely to rate their health as "fair" or "poor" compared with persons having only back problems or compared with persons in the civilian noninstitutionalized population as a whole. Musculoskeletal disorders accounted for a considerable proportion of all disability days reported by the total civilian noninstitutionalized population: 13 percent of restricted-activity days, 8.8 percent of bed-disability days, and 11.2 percent of all work-loss days were directly attributable to musculoskeletal conditions. The disabling effects of musculoskeletal problems pose a significant economic burden; they accounted for a total of $3.9 billion in lost productivity costs during 1980 for employed persons in the work force and for homemakers. For persons with musculoskeletal problems, the mean number of ambulatory visits per year was nearly twice the rate of 5.2 for the general civilian noninstitutionalized population. Of ambulatory visits made to all health care providers by persons with these conditions, 35.6 percent were related in some way to the treatment of their musculoskeletal problems. Musculoskeletal conditions are somewhat different from many other illnesses because their treatment is within the professional domain of several types of health care providers. Approximately 13 percent of persons with any type of musculoskeletal disorder received care from chiropractors during the year and this figure rose to nearly 30 percent for back problems only. However, nearly 33 percent of persons with musculoskeletal problems made no visits for treatment of their condition.(ABSTRACT TRUNCATED AT 400 WORDS)

Incidence, utilization, and costs associated with acute respiratory conditions, United States, 1980.

Acute respiratory conditions are common causes of health disturbance in the general population. They are generally self-limiting, although occasionally recurrent, and seldom result in large health care costs for each episode of illness. The National Medical Care Utilization and Expenditure Survey (NMCUES), conducted during 1980, provided an opportunity to assess the effect of acute respiratory conditions on utilization of medical services and on functional capability as well as the cost of related medical care. Acute respiratory conditions were reported by survey respondents and separated into five subgroups: colds, influenza, nasopharyngitis, otitis media, and lower respiratory infections. Allergic conditions and chronic respiratory disorders (tuberculosis, chronic obstructive pulmonary disease, and pneumoconioses) were excluded. The subgroupings of acute respiratory conditions appear to separate the disorders in a manner consistent with the epidemiologic characteristics of each condition. About one-half (50.4 percent) of the U.S. civilian noninstitutionalized population had one or more acute respiratory conditions during 1980. The highest rates for upper respiratory conditions (colds, influenza, nasopharyngitis, and otitis media) were reported for those under 18 years of age, and rates were lower in successively older groups. Lower respiratory infection rates were higher in the youngest and oldest groups. Despite a high incidence in the general population, most symptomatic episodes of colds, influenza, and nasopharyngitis did not result in ambulatory care visits or hospital admissions. Otitis media and lower respiratory infections were more often associated with medical visits. Acute respiratory conditions were associated with lower disability levels than the average for the U.S. civilian noninstitutionalized population during 1980 (5.9 restricted-activity days for acute respiratory conditions, compared with an overall average of 13.8 restricted-activity days). Persons with upper respiratory conditions (colds, influenza, otitis media, and nasopharyngitis) averaged 2.3 to 5.4 restricted-activity days, but persons with lower respiratory infections experienced an average of 8.2 restricted-activity days. Indirect costs attributed to acute respiratory conditions in 1980 were $7.7 billion for employed persons and $698 million for homemakers, for a total of $8.4 billion, about the same as total direct costs ($8.3 billion). These indirect costs were several times larger than the annual indirect costs estimated for either cardiovascular diseases or musculoskeletal diseases, two common chronic or recurrent condition groups. The high indirect costs reflect the high frequency of episodes in the general population during 1980 and the greater likelihood of associated bed-disability and work-loss days than for other conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Costs of illness: United States, 1980.

The total costs of illness and injury in the U.S. civilian noninstitutionalized population in 1980 amounted to $381.7 billion. The direct costs of illness and injury--resource expenditures for the diagnosis, treatment, and management of medical and dental conditions--were $153.9 billion, or 40.3 percent of total costs. Indirect costs--economic losses from morbidity and mortality--were $227.9 billion, or 59.7 percent of total costs. Of indirect costs, $104.9 billion resulted from productivity losses because of morbidity, and $123.0 billion represent the present value of lost productivity from premature mortality based on a net effective discount rate of 4 percent. These estimates, based on data from the 1980. National Medical Care Utilization and Expenditure Survey (NMCUES), differ from other estimates of the costs of illness and injury in 1980 (Gibson and Waldo, 1982; Rice, Hodgson, and Kopstein, 1985). The differences, which can be resolved, are attributable to two major factors: (1) NMCUES includes only the civilian noninstitutionalized population, but the other estimates include the institutionalized population and the military; and (2) NMCUES indirect cost estimates for the population unable to work include persons who were retired for health reasons in 1979 and 1980, disabled homemakers, and other persons who were disabled for the entire year 1980 but were not retired for health reasons in 1979, but the Rice et al. estimates do not include the last two categories in the population unable to work. The principal NMCUES findings on the total costs of illness in the civilian noninstitutionalized population reinforce the importance of considering distributional effects. Persons 65 years of age and over represent one-tenth of this population yet account for more than one-fourth of direct costs and more than their share of total costs, even though the institutionalized elderly are excluded. More than two-thirds of total costs for this age category are accounted for by direct costs. Direct costs also account for more than two-thirds of total costs for people under 17 years of age. However, this youngest age category, which constitutes over one-fourth of the civilian noninstitutionalized population, generates only 12.3 percent of direct costs. In contrast, indirect costs account for well more than 60 percent of total costs for the working-age population (17-64 years of age). Within the working-age population, per capita direct costs are highest among persons who are not full participants in the work force, many of whom are not working full time or at all because of injury or ill health.(ABSTRACT TRUNCATED AT 400 WORDS)

Epidemiology of blindness in Nepal.

This report presents the major findings of the Nepal Blindness Survey, the first nationwide epidemiological survey of blindness, which was conducted in 1979-80. The survey was designed to gather data that could be used to estimate the prevalence and causes of blindness in the country. Ancillary studies were conducted to obtain information on socioeconomic correlates and other risk factors of blinding conditions and patterns of health care utilization.The nationwide blindness prevalence rate is 0.84%. Cataract is the leading cause of blindness, accounting for over 80% of all avoidable blindness. Trachoma is the most prevalent blinding condition, affecting 6.5% of the population. Very few cases of childhood blindness were detected.The implications of the survey findings for programme planning, health manpower development, and health education are discussed.