G. Edward Miller

Health expenditure estimation and functional form: applications of the generalized gamma and extended estimating equations models.

Health-care expenditure regressions are used in a wide variety of economic analyses including risk adjustment and program and treatment evaluations. Recent articles demonstrated that generalized gamma models (GGMs) and extended estimating equations (EEE) models provide flexible approaches to deal with a variety of data problems encountered in expenditure estimation. To date there have been few empirical applications of these models to expenditures. We use data from the US Medical Expenditure Panel Survey to compare the bias, predictive accuracy, and marginal effects of GGM and EEE models with other commonly used regression models in a cross-validation study design. Health-care expenditure distributions vary in the degree of heteroskedasticity, skewness, and kurtosis by type of service and population. To examine the ability of estimators to address a range of data problems, we estimate models of total health expenditures and prescription drug expenditures for two populations, the elderly and privately insured adults. Our findings illustrate the need for researchers to examine their assumptions about link functions: the appropriate link function varies across our four distributions. The EEE model, which has a flexible link function, is a robust estimator that performs as well, or better, than the other models in each distribution.

Prevalence of Potentially Inappropriate Medication Use in Older Adults Using the 2012 Beers Criteria

To use the most recently available population‐based data to estimate potentially inappropriate medication (PIM) prevalence under the 2012 update of the Beers list of PIMs and to provide a benchmark from which to measure future changes.

Trends in prescription drug expenditures by Medicaid enrollees.

Objective:As prescription drug expenditures consume an increasingly larger portion of Medicaid budgets, states are anxious to control drug costs without endangering enrollees’ health. In this report, we analyzed recent trends in Medicaid prescription drug expenditures by therapeutic classes and subclasses. Identifying the fastest growing categories of drugs, where drugs are grouped into clinically relevant classes and subclasses, can help policymakers decide where to focus their cost containment efforts. Methods:We used data from the Medical Expenditure Panel Survey linked to a prescription drug therapeutic classification system, to examine trends between 1996/1997 and 2001/2002 in utilization and expenditures for the noninstitutionalized Medicaid population. We separated aggregate trends into changes in population with use and changes in expenditures per user, and percent generic. We also highlighted differences within the Medicaid population, including children, adults, disabled, and elderly. Results:We found rapid growth in expenditures for antidepressants, antipsychotics, antihyperlipidemics, antidiabetic agents, antihistamines, COX-2 inhibitors, and proton pump inhibitors and found evidence supporting the rapid take-up of new drugs. In some cases these increases are the result of increased expenditures per user and in other cases the overall growth also comes from an increase in the population with use. Conclusions:Medicaid programs may want to reassess their cost-containment policies in light of the rapid take-up of new drugs. Our analysis also identifies areas in which more information is needed on the comparative effectiveness of new versus existing treatments.

Explaining racial and ethnic differences in children's use of stimulant medications.

Objectives:To document and explain racial/ethnic differences in the use of stimulant drugs among US children. Data and Methods:We use a nationally representative sample of children ages 5–17 years old from the Medical Expenditure Panel Survey (MEPS) for the years 2000–2002. We estimate race-specific means and regressions to highlight differences across groups in individual/family characteristics that may affect stimulant use and differences in responses to these characteristics. Then, we use Oaxaca-Blinder decomposition methods to quantify the portion of differential use explained by differences in individual/family characteristics. Finally, we use pooled regressions with race/ethnicity interactions to formally test the hypothesis that responses to perceived mental health and behavioral problems vary across groups. Results:White children are about twice as likely to use stimulants as either Hispanic or Black children. Differences in individual/family characteristics account for about 25% of the difference between whites and Hispanics, but for none of the difference between whites and blacks. Pooled regressions show that racial/ethnic gaps in stimulant use persist among children with otherwise similar reported mental health conditions. Conclusions:Our finding that the majority of racial/ethnic differences in childrens stimulant use is explained by differences in responses to individual/family characteristics highlights the importance of further research to examine the reasons for these differences. It is striking that children with otherwise similar reports of mental health problems have such different outcomes in terms of stimulant use. Potential explanations range from discrimination to cultural differences by race/ethnicity or community.

Children and antibiotics : Analysis of reduced use, 1996-2001

Objectives:We investigated trends in antibiotic use by U.S. children, from 1996 to 2001, a period that followed the launch of national campaigns to promote the appropriate use of antibiotics. Data and Methods:We used nationally representative data from the Medical Expenditure Panel Survey for the years 1996–2001 to examine trends in antibiotic use and the contributions of changes in ambulatory visits and prescribing to these trends. We investigated trends in the use of antibiotics overall and for respiratory tract infections and examined these trends within subgroups of children defined by race/ethnicity and income. Results:From 1996 to 2001, the proportion of children with antibiotic use overall and for respiratory tract infections decreased by 8.5 percentage points and 5.1 percentage points, respectively. Overall, the probability of a child having an ambulatory visit did not change. The decrease in overall antibiotic use resulted entirely from an increase in the probability that a child had an ambulatory visit(s) with no antibiotic use. By contrast, a decline in the probability that a child had a visit for a respiratory tract infection accounted for two-thirds of the reduction in antibiotic use for these conditions. The decline in overall use for white-other non-Hispanic children (−10.2 percentage points) was more than double the decline for black non-Hispanic or Hispanic children. Conclusion:Childrens use of antibiotics, overall and for respiratory tract infections, showed significant declines from 1996 to 2001. The apparent response to campaigns to reduce inappropriate antibiotic use was widespread as reductions in use were found in all subgroups of children examined.

Explaining racial and ethnic differences in antidepressant use among adolescents.

We investigate the extent to which antidepressant use among adolescents varies across racial and ethnic subgroups. Using a representative sample of U.S. adolescents, we find that non-Hispanic White adolescents are over twice as likely as Hispanic adolescents, and over five times as likely as non-Hispanic Black adolescents to use antidepressants. Results from a decomposition analysis indicate that racial/ethnic differences in characteristics, including household income, parental education, health insurance, and having a usual source of care explain between one half and two thirds of the gap in antidepressant use between Hispanics and non-Hispanic Whites. In contrast, none of the gap between Whites and Blacks in antidepressant use is explained by differences in observed characteristics. Further analysis suggests that there are large racial/ethnic differences in the extent to which behavioral and mental health problems prompt antidepressant use and that this may, in part, account for the large differences across race/ethnicity observed in our study.

Narrow- and Broad-Spectrum Antibiotic Use among U.S. Children.

OBJECTIVES To provide updated estimates of narrow- and broad-spectrum antibiotic use among U.S. children. DATA SOURCES Linked nationally representative data from the 2004-2010 Medical Expenditure Panel Survey Household Component and the 2000 Decennial Census. STUDY DESIGN Relationships between individual-, family-, and community-level characteristics and the use of antibiotics overall and in the treatment of respiratory tract infections (RTIs) are examined using multinomial choice models. PRINCIPAL FINDINGS More than one quarter (27.3 percent) of children used at least one antibiotic each year with 12.8 percent using broad-spectrum and 18.5 percent using narrow-spectrum antibiotics. Among children with use, more than two-thirds (68.6 percent) used antibiotics to treat RTIs. Multivariate models revealed many differences across groups in antibiotic use, overall and in the treatment of RTIs. Differential use was associated with a broad range of factors related to need (e.g., age, health status), resources (e.g., insurance status, parental income, and education), race-ethnicity, and Census region. CONCLUSIONS Despite encouraging reports regarding the declining use of antibiotics, large differences in use associated with resources, race-ethnicity, and Census regions suggest a need for further improvement in the judicious and appropriate prescribing of antibiotics for U.S. children.

Adults with Diagnosed and Untreated Diabetes: Who Are They? How Can We Reach Them?

Untreated or undertreated diabetes can cause debilitating complications such as blindness and amputations. Information about the factors associated with diagnosed but untreated diabetes may help target efforts to promote appropriate treatment. Using the Medical Expenditure Panel Survey, we examine: (1) use of insulin or oral medications, (2) use of diet only, and (3) no treatment. We analyze covariates of this trichotomous outcome using multinomial logit regression. Among adults diagnosed with diabetes, 87.0% used oral medications or insulin, 10.6% used diet only, and 2.4% were untreated. Lacking a usual source of care, poor mental health, being single, and being an Asian/Pacific Islander are associated with lack of treatment. Better health, lacking a usual source of care, and attitudes against medical care are associated with using diet only. Adults with diagnosed but untreated or undertreated diabetes may be difficult for service providers to reach, and multiple strategies are needed to initiate treatment.

Changes in Pharmaceutical Treatment of Diabetes and Family Financial Burdens

Recent changes in diabetes treatment guidelines and the introduction of new, more expensive pharmaceuticals appear to increase the financial challenges for nonelderly adults with diabetes. The authors used Medical Expenditure Panel Survey data to examine changes in the prevalence of diabetes and comorbidities, diabetes treatment, financial burdens, and the relationship between high financial burdens and patient characteristics. From 1997-1998 to 2006-2007, the total number of nonelderly adults treated for diabetes nearly doubled, from 5.4 to 10.7 million, and the proportion of diabetes patients using multiple drugs to treat their condition increased significantly. About a fifth of diabetes patients spent 10% or more of their family income on health care, and about one in nine spent 20% or more of their family income on health care. In 2006-2007, diabetes patients who were older, female, in poor health, or lacked insurance were more likely than others to have high burdens.

Does increased adherence to medications change health care financial burdens for adults with diabetes

The aim of the present study was to investigate increased out‐of‐pocket drug costs and financial burdens of achieving adherence to oral antidiabetic medications and medications for prevalent comorbidities.