摘要：Objectives. This study sought to determine the effect of cost sharing on medical care use for acute symptoms and on health status among chronically ill adults. Methods. Data from the Medical Outcomes Study were used to compare (1) rates of physician care use for minor and serious symptoms and (2) 6- and 12-month follow-up physical and mental health status among individuals at different levels of cost sharing. Results. In comparison with a no-copay group, the low- and high-copay groups were less likely to have sought care for minor symptoms, but only the high-copay group had a lower rate of seeking care for serious symptoms. Follow-up physical and mental health status scores were similar among the 3 copay groups. Conclusions. In a chronically ill population, cost sharing reduced the use of care for both minor and serious symptoms. Although no differences in self-reported health status were observed, health plans featuring cost sharing need careful monitoring for potential adverse health effects because of their propensity to reduce use of care that is considered necessary and appropriate. Requiring patients to pay a portion of their medical bill out of pocket, also known as cost sharing, sharply reduces their use of health care resources. 1– 9 Use of this strategy by health insurance plans to lower expenditures is controversial: proponents argue that health care consumers will appropriately ration their use of medical services; critics fear that this financial disincentive will lead patients to use less care that may be necessary and will result in worse health outcomes. The RAND Health Insurance Experiment, which randomized subjects to health plans with varying coinsurance levels, did not provide a definitive judgment in regard to these issues. Relative to free care, coinsurance reduced use of both unnecessary and necessary care 1, 4 but had only a small adverse effect on health outcomes. 1, 10, 11 Because the study excluded disabled and elderly individuals, subjects may have been too healthy for a greater negative health effect to be observed. Thus, we analyzed data from the Medical Outcomes Study, which prospectively followed chronically ill adults, to determine whether cost sharing deters use of care and leads to subsequent worse health outcomes among a population whose health may be more vulnerable to use disincentives.
