Spillover effects of community uninsurance on awareness, treatment, and control of hypertension among insured adults

Abstract

Background: Although studies have shown that a high rate of uninsurance in a community reduces access to and satisfaction with health care among the insured population, little is known about whether the community uninsurance rate also affects quality of care and clinical outcomes among the insured.

Objective: To assess the spillover effects of the rate of uninsurance in a community on the awareness, treatment, and control of hypertension, a chronic condition responsible for substantial morbidity and mortality in the United States, among insured adults.

Research design: NHANES III (1988-1994) and the 1999-2010 NHANES were linked to data from the Current Population Survey, Area Resource File, and InterStudy Competitive Edge. Multivariate probit regression models used 2 alternative estimation approaches: (1) maximum likelihood estimation, and (2) 2-stage residual inclusion estimation, an instrumental variables method.

Main outcome measures: Six dichotomous outcomes included: awareness among all subjects with hypertension; treatment among all subjects with hypertension and among subjects who were aware of their condition; and control among all subjects with hypertension, among subjects who were aware of their condition, and among subjects receiving treatment.

Results: A 10 percentage point increase in the community uninsurance rate reduced the probability of receiving antihypertensive medications by 4.2 percentage points among insured hypertensive adults and by 5.5 percentage points among insured hypertensive adults who were aware of their hypertension. A 10 percentage point increase in the community uninsurance rate also resulted in a 6.8 percentage point decline in the probability of blood pressure control among insured hypertensive adults who were aware of their condition.

Conclusions: Nationally, the Affordable Care Act is expected to reduce the number of uninsured by >30 million by 2016, although changes will be experienced by communities to a greater or lesser extent depending on the existing numbers and characteristics of the uninsured in the area and the ways in which health care reform is implemented. Our results suggest that reductions in the community uninsurance rate have the potential to improve quality of care and clinical outcomes among the insured.