Circumstances at HIV diagnosis and progression of disease in older HIV-infected Americans.

OBJECTIVES: This study identified age-related differences in diagnosis and progression of HIV by analyzing a nationally representative sample of HIV-infected adults under care in the United States. METHODS: We compared older (> or = 50 years) and younger participants stratified by race/ethnicity. Regression models controlled for demographic, therapeutic, and clinical factors. RESULTS: Older non-Whites more often had HIV diagnosed when they were ill. Older and younger patients were clinically similar. At baseline, however, older non-Whites had fewer symptoms and were less likely to have AIDS, whereas at follow-up they had a trend toward lower survival. CONCLUSIONS: Later HIV diagnosis in non-Whites merits public health attention; clinical progression in this group requires further study.

Interrelated family-building behaviors: cohabitation, marriage, and nonmarital conception.

Data from the National Longitudinal Study of the High School Class of 1972 are used to estimate a series of models of entry into marriage, entry into cohabitation, and nonmarital pregnancy. Our models account explicitly for the endogeneity of one outcome as a predictor of another by taking into account both heterogeneity across individuals due to unmeasured factors that may affect all these outcomes and the correlation in the unmeasured factors across processes. We find that these heterogeneity components are strongly and positively related across the outcomes. Women who are more likely to cohabit, marry, or become pregnant while unmarried are also more likely to do each of the others. Although black and white women differ in the likelihood of these behaviors, the interrelations of the behaviors are quite similar across groups.

Insurance coverage for prescription drugs: effects on use and expenditures in the Medicare population.

BACKGROUND: Although most of the elderly are covered by Medicare, they potentially face large out-of-pocket costs for their health care because of excluded services. Aside from nursing home care, the exclusion of prescription drugs is one of the most significant. Several earlier policy initiatives have proposed adding prescription drug coverage to the Medicare program. To determine the effects of such an expansion, one must account for the potential increase in the demand for prescription drugs from providing insurance coverage. METHODS: The study uses a new data source, the RAND Elderly Health Supplement to the 1990 Panel Study of Income Dynamics (PSID). The endogenity of insurance coverage is tested using instruments that exploit the longitudinal nature of the data. Equations are estimated on 910 persons (> or = 66 years) using a two-part model. RESULTS: Insurance coverage for prescription drugs significantly increases the probability of use, but not of total expenditures, among those who use prescription drugs. However, insurance coverage significantly lowers out-of-pocket expenditures, thereby decreasing the financial burden on elderly households associated with prescription drug use. Medicaid coverage has effects that are smaller than those for private insurance, but the magnitude is less precisely estimated. These findings imply that if prescription drug coverage were added to Medicare, expected expenditures on drugs would rise by on average $83 for each elderly Medicare beneficiary (in 1990 dollars), although this increase is significant only at the 90% level. If the benefit had been included under Medicare, expected spending on prescription drugs by the elderly would have risen by approximately 20%, or $2.6 billion in 1990.

The financial burden of prescription drug use among elderly persons.

Expenditures for prescription drugs are not covered by Medicare and are thus a potential source of large out-of-pocket expenditures for elderly persons. This study, using a new data source, the 1990 Elderly Health Supplement to the Panel Study of Income Dynamics (PSID), demonstrates that, among elderly persons, insurance coverage for drugs reduces the fraction of household income spent on prescription drugs by 50 percent. Groups most likely to benefit from insurance coverage are elderly women and those with common chronic conditions, low incomes, and rural residences.

Long-term determinants of patterns of health insurance coverage in the Medicare population.

Using data from the 1990 Health Supplement to the Panel Study of Income Dynamics, we examine the determinants of patterns of insurance coverage among the elderly. Among those with supplemental insurance through an employment-based source, the primary determinant of having insurance is work history, specifically job tenure and occupation of household heads and their spouses. Among those who do not have employer-provided insurance, wealth is the most important economic factor in the purchase of private insurance. Blacks, persons with less education and women household heads are less likely to purchase supplemental insurance. We find little evidence that persons in prior poor health are more likely to purchase supplemental insurance, and the most important determinant of dental or drug coverage is having employer-based insurance. The current trend toward decreased generosity of post-retirement benefits implies that fewer older Americans will have insurance for these services.

Functional associations of "trouble seeing".

The purpose of this study was to determine how vision problems affect health status. The information was collected in 1990 from 2,249 household heads and spouses over 50 years of age during an annual survey of a nationally representative sample that was adjusted for attrition and nonresponse. Vision problems were defined as "trouble seeing (even with glasses or contact lenses)." Health status was measured principally with the Medical Outcomes Study Short-Form 36. Regression analyses found a significant relationship between "trouble seeing" and each of five health-status domains. We conclude that it may not be appropriate to require specific functional limitations as a precondition for cataract surgery and that instruments for measuring functional disabilities related to vision should include more general questions.

Motives for intergenerational transfers: evidence from Malaysia.

In this paper we discuss a number of hypotheses about motives for intergenerational transfers within the family. We use data on time and money transfers between generations in Malaysia, where there is neither Social Security nor Medicare, to explore these hypotheses empirically. We find evidence supporting the hypotheses that children are an important source of old age security and that old age security is, in part, children's repayment for parental investments in their education. This repayment is partly a function of the children's income and, in the case of females, a function of their spouse's income. We also find evidence supporting the hypotheses that parents and children engage in the exchange of time help for money.

Reproductive history, socioeconomic status, and self-reported health status of women aged 50 years or older.

OBJECTIVES: This paper describes the relationship between self-reported general health status and several facets of reproductive history. METHODS: We analyzed survey data on a national probability sample of 1341 women aged 50 and older from the Panel Study of Income Dynamics. We used multivariate regression techniques to control for differences in health indices that assessed health status and functioning. RESULTS: Women with a history of six or more completed pregnancies were found to be disadvantaged in educational attainment, financial resources, and health status compared with women with no or fewer pregnancies. When current sociodemographic factors were controlled, six or more pregnancies were associated with worse general health and worse physical role functioning. When sociodemographic factors and number of births were controlled, among women with at least one delivery, women who had experienced an infant's death reported worse health as measured by all three indices. Women with a first delivery before the age of 18 were more likely to report a functional limitation. CONCLUSIONS: Women with high parity status, a history of an infant's death, and an early first pregnancy may be at greater risk of poor health in later life.

Linking Medicare and national survey data.

Administrative records from the Medicare Program of the Health Care Financing Administration provide a valuable source of information for research on medical and public policy issues. This administrative database contains information on utilization of covered medical services, diagnoses, episodes of illness, and Medicare-covered costs of health care. Combining such data with information from national surveys on health status, demographics, and socioeconomic attributes substantially expands the scope of potential research questions that can be addressed. This article discusses the benefits and difficulties of linking Medicare administrative data with survey data and provides brief summaries of five national surveys of elderly U.S. citizens. These surveys can be valuable resources for examining the health status and life experiences of the Medicare population.

Marital status and mortality: the role of health.

Prior literature has shown that married men live longer than unmarried men. Possible explanations are that marriage protects its incumbents or that healthier men select themselves into marriage. Protective effects, however, introduce the possibility of adverse selection: Those in poor health have incentive to marry. In this paper we explore the role of health in explaining mortality and marriage patterns, and distinguish protective effects from two types of selection effects. We find adverse selection on the basis of health (unhealthy men tend to (re)marry sooner) and positive selection on the basis of unmeasured factors that both promote good health and encourage marriage.

Child mortality in Malaysia: explaining ethnic differences and the recent decline.

Infant and child mortality rates have dropped sharply for all ethnic groups in Malaysia between 1950 and 1988, but persistent ethnic differences remain. In this article we assess the contribution of several potential reasons both for the decline and the remaining differences between the Malay and Chinese sub-populations. Increased use of health inputs is found to explain a substantial part of the decline, but increased education of mothers, and income growth are also important. Longer spacing between births, and, higher average age at birth as a result of lower fertility and higher age at marriage provide only a marginal direct contribution to the fall in mortality. We find that lower mortality among the Chinese is accounted for by their higher incomes and greater propensty to purchase medical care. We also control for self-selection among users of medical care, and find that those who use health care in Malaysia tend to be subject to higher-than-average risks.

Dental expenditures and insurance coverage among older adults.

Using data on 975 elderly persons from the 1990 Health Supplements to the Panel Study of Income Dynamics, we describe the predictors of expenditures for dental services. Forty-four percent of elderly persons reported using some dental services within a year. Thirteen percent had private dental insurance, and 8% had a separate dental policy. The average total expenditure for those who used any dental services was $378, 88% of which was paid out-of-pocket. Persons with a separate dental insurance policy, younger and better educated persons, and those with greater financial resources were more likely to use dental services.

Premarital cohabitation and subsequent marital dissolution: a matter of self-selection?

Married couples who began their relationship by cohabiting appear to face an increased risk of marital dissolution, which may be due to self-selection of more dissolution-prone individuals into cohabitation before marriage. This paper uses newly developed econometric methods to explicitly address the endogeneity of cohabitation before marriage in the hazard of marital disruption by allowing the unobserved heterogeneity components to be correlated across the decisions to cohabit and to end a marriage. These methods are applied to data from the National Longitudinal Study of the High School Class of 1972. We find significant heterogeneity in both cohabitation and marriage disruption, and discover evidence of self-selection into cohabitation.

Health inputs and child mortality: Malaysia.

This paper is concerned with the relationship between child mortality and the use of health care. We develop a simultaneous model of fetal and postnatal mortality risks and input demand equations for prenatal medical care and institutional delivery. This model is applied to retrospective data from Peninsular Malaysia covering 1950-1988. The results show that prenatal medical care and institutional delivery have strong beneficial effects on child survival probabilities, and that these effects are substantially underestimated when adverse self-selection among users of health care is ignored. The effectiveness of prenatal health care in Malaysia improved until 1980, and then deteriorated. We find that the risk of infant and child mortality is not independent of fetal survival, but show that ignoring selective fetal survival introduces only mild biases in infant and child mortality estimation. Higher infant and child mortality rates among young mothers are partly explained by their lower likelihood of purchasing health care.

Sociodemographic and health factors in driving patterns after 50 years of age.

Data from the 1990 Panel Study of Income Dynamics were used to predict, by means of logistic regression, the likelihood that people who had previously driven would continue to drive and to drive after dark after 50 years of age. The results support the conclusion that driving patterns appear to be explained partly by a combination of sociodemographic factors and health status. Furthermore, it is shown that those reported to drive for nondrivers appear to be the same individuals known to provide most informal support for functionally impaired elderly people.

A joint model of marital childbearing and marital disruption.

Married couples with children appear to be less likely to end their marriages than childless couples, especially when the children are young. Although this suggests that children affect the chances that their parents will divorce, the process may not be so simple: the chances that the marriage will last also may affect couples' willingness to make the commitment to the marriage implied by having children. This paper uses data from the Panel Study of Income Dynamics (PSID) to test the hypothesis that the risk of disruption faced by a married woman affects the chances that she will conceive and bear a child. The model used takes into account the simultaneous relationships between marital dissolution and marital fertility by including the hazard of disruption as a predictor of timing and likelihood of marital conception, and by including the results of previous fertility decisions as predictors of disruption of the marriage. We find that the hazard of disruption has strong negative effects on the hazard of marital childbearing, lengthening the intervals between births and decreasing the chances that a child will be born. This effect appears to be strongest for women who have had at least one child, either before or during the current marriage, although it is also large for childless women. Explicitly including the hazard of disruption in models of marital childbearing has sizable and important effects on many predictors of fertility.

Simultaneous equations for hazards: marriage duration and fertility timing.

"This paper develops an approach to simultaneity among hazard equations which is similar in spirit to simultaneous Tobit models. It introduces a class of continuous time models which incorporates two forms of simultaneity across related processes--when the hazard rate of one process depends (1) on the hazard rate of another process or (2) on the actual current state of or prior outcomes of a related multi-episode process. This paper also develops an approach to modeling the notion of 'multiple clocks' in which one process may depend on the duration of a related process, in addition to its own. Maximum likelihood estimation is proposed based on specific parametric assumptions. The model is developed in the context of and empirically applied to the joint determination of marital duration and timing of marital conceptions."

Preventive care: do we practice what we preach?

We used insurance claims from enrollees in the Rand Health Insurance Experiment to determine the amount of selected components of preventive care received by a representative sample of the non-aged population in the United States and to determine whether insurance coverage was an important determinant of that amount. Only 45 percent of infants received timely immunization for DPT and polio; 93 per cent received some well child care by 18 months of age. In the three-year experimental period, only 4 per cent of adults had a tetanus shot, 66 per cent of women aged 17-44 and 57 per cent aged 45-65 received a Pap smear, and 2 per cent of women aged 45-65 had a mammogram. Cost sharing was associated with even less preventive care: 60 per cent of children on the free plan and 49 per cent on cost sharing plans received preventive care of any type. For adults, women on the free plan received more preventive care of several kinds, and those aged 45-65 received more Pap smears than those on cost-sharing plans. Even with free care, most enrollees did not receive adequate preventive care. Thus, free care alone, while significant, is not a sufficient incentive to providing recommended levels of preventive care. The average per person insurance charge for increasing the amount of preventive care to a level consistent with that recommended would be $22 for a complete set of immunizations by age 18 months, $9 for a Pap smear every three years, and $97 for a Pap test and mammogram every three years.

Socioeconomic factors affecting the utilization of surgical operations.

Between 1963 and 1970 public programs were introduced to reduce inequalities in access to medical care. We examined differentials in surgical utilization among socioeconomic groups in 1970 as well as changes between 1963 and 1970. Multivariate analysis of National Health Interview Survey data indicated that large increases in surgical utilization occurred among disadvantaged groups: the aged, lower educated and nonwhites in urban areas. Some differential by race and residence remains, but is strongly related to income. Income had a large positive effect on surgical utilization, but this effect was less strong in 1970 than in 1963. Education had a negative effect on surgical utilization. Eleven surgical procedures were selected and scaled on indexes of "complexity," "urgency" and "necessity." These indexes do not vary among demographic groups that have significant differences in surgical utilization. However, lower-income groups utilized to a lesser extent procedures rated lowest on the necessity scale.