Our findings suggest that having both a usual place and a usual provider are key to determining whether adults receive recommended screening and prevention services. The more comprehensively defined source of care appears to be associated with substantially improved likelihood of receiving recommended preventive services, which may ultimately contribute to improved health. Just having a usual place for preventive care is less effective.
Our findings are consistent with previous studies that examined the impact of place and/or provider on receipt of preventive services and recommended screenings. In a study of preventive services for women and children, Ettner found that having a usual source of care (place) was strongly associated with receipt of Pap smears, breast exams, and mammograms.12
Doescher et al. also found that continuity of both place and provider was significantly associated with increased receipt of flu shots and mammograms, above and beyond continuity of place alone.13
Again, our contribution is that our data source included a large adult sample with both survey questions that allowed us to test the effects of having only a usual place for preventive care or having both a usual place and a usual provider.
We also found that while existing surveys of health and health care utilization provide some limited information on the medical home construct, there should be a concerted effort to determine the key factors associated with having a usual place and a usual provider that increase the likelihood of use of preventive services and, in turn, increased health status. Yet some of these characteristics may be more personal and therefore difficult to assess. For example, there is evidence that the quality of the relationship, the ability of the provider to communicate, or the amount of time the provider spends with a patient influences use of preventive services.3,8
It will be critical to understand the relationship of these attributes to improvements in patient care and health status if the medical home construct is to take hold for adult populations.
Our study findings should be considered in light of several limitations. First, our usual source of care classification was based on a series of questions pertaining to usual place and usual provider. While the questions about place specifically distinguish a place for preventive care versus other health care, the provider question does not. It is possible that some of our subjects classified as having a usual place and provider for preventive care did not have a usual provider for preventive care. Second, some subjects may have been misclassified in the receipt of preventive care measures due to limitations of data availability in the NHIS. For example, the ACS guidelines for Pap smear testing take into account previous Pap smear results. NHIS does not contain data on previous Pap test results, so our up-to-date Pap test measure is based only on years since last Pap test. Finally, although we found strong statistically significant associations between source of care and receipt of preventive care services, it is possible that this observed relation is due to some other unobserved confounder or due to reverse causality. In other words, those who report a usual place and a usual provider may be systematically different from those who do not. These systematic differences may not have been fully accounted for by our available covariates, which resulted in significantly higher odds of service receipt even after covariate adjustment. However, given the magnitude of our effect estimates, an omitted covariate would have to be extraordinarily strong to attenuate these findings. It is also possible that those who have specifically sought preventive cares services are more likely to report having usual place and a usual provider because of their recent use of services.
We would also like to place our findings in the context of the benefits of primary care and prevention. A recent report on preventive care demonstrates the under-use of effective preventive care in the US resulting in the loss of life, preventable poor health status, and inefficient use of medical care.14
Specific to our measures tested, the study found that 12,000 lives would be saved each year if the portion of adults age 50 and older and others at risk were immunized against influenza, and nearly 4,000 lives would be saved each year if more women age 40 and older were screened for breast cancer.
We have demonstrated that having a usual place and usual provider are associated with an increased likelihood of receiving preventive services and recommended screenings compared with having no usual source of care. However, we know very little about the characteristics of those places and the providers that are seen. If, as the American College of Physicians6
and others advocate, all US citizens are to have a medical home, then we need to know much more about what constitutes a medical home and how to measure those attributes that contribute to success. We believe the place to start is for a patient to be linked with a provider who is seen routinely at the same place every time.