Using data from 15,792 people participating in the Atherosclerosis Risk in Communities Study, this study examined whether lack of health insurance affected cardiovascular outcomes. Although evidence exists that lack of insurance affects access to health care, prospective studies illuminating relationships between lack of insurance and health outcomes are still rare.
The authors hypothesized three consequences of lacking health insurance that could affect cardiovascular health: infrequent physical exams, insufficient information about personal risk factors for heart disease, and poor control of these risk factors. Participants were surveyed at four separate visits to assess these effects. Outcome measures of interest were myocardial infarction (MI), stroke, and death by any cause. Data analysis indicated that lack of insurance was associated with increased risk of stroke and of death by all causes. Lack of insurance also was associated with increased risk of MI, but the increase was not statistically significant. The hypothesis that lack of insurance affected frequency of exams and awareness of risk factors was borne out by the data. The third hypothesized consequence, that risk factors would be less well-controlled in uninsured patients, was true for some risk factors and not for others. For example, insurance status in those aware of their risk factors did not affect control of hyperlipidemia but did affect control of hypertension. Hypertension is the most powerful risk factor for stroke.
Limitations of this study include that insurance information was gathered for purposes other than the objectives of this study; therefore, insurance history prior to this study was not obtained. Also "being insured" includes various types of insurance which may not be equal to one another. Further studies investigating type and duration of insurance will be valuable in quantifying the risks of adverse health outcomes associated with access to medical care.