How much does health care affect longevity?

Much of the political discourse around health focuses on expanding access to health insurance. But how much does health care really matter for health? Of course, access to preventive services, care for chronic conditions, and timely medical treatment can be lifesaving. However, compared to social and behavioral factors like neighborhood environment, family income, education, and healthy habits, the impact of medical care on health might be smaller than we thought. 

In a recent study in the Annals of Family MedicineDr. Robert Kaplan and Dr. Arnold Milstein from the Stanford University School of Medicine, explore the question of how much health care access and delivery contribute to longevity and other health outcomes.

They review several different methods of estimated health care’s contribution to health: analyzing the factors associated with premature mortality for leading causes of death; measuring the impact of diagnoses, behavioral, and social factors on variation in mortality using Medicare claims data; measuring the impact of social and clinical factors on health outcomes in the County Health Rankings; and evaluating the impact of health care access on mortality in the RAND Health Insurance Experiment. 

While these methods were quite different, the results of these four studies were relatively similar. Kaplan and Milstein found that estimates of health care’s contribution to premature mortality ranged from 0% to 17%, depending on the method. 

“The various methods were consistent in showing that social and behavioral factors account for a much higher percentage of the variation in premature mortality than health care does,” the authors write.

Estimates of the impact of behavioral factors were wider, ranging from 16-69%; social factors contributed an estimated 15-46% to premature mortality. The authors note, however, that these factors should not add up to 100%, since social circumstances almost always affect health behaviors as well as access to health care.

Health care institutions are recognizing the importance of preventing health problems by integrating health care and social services. Recently, Kaiser Permanente announced the launch of Thrive Local, a network that will connect all of its members to community resources to address patients’ social needs, such as food and housing. 

Boston Medical Center has also tested an EHR screening tool to identify social needs for patients. They found the tool was effective in identifying social needs such as unemployment, food insecurity, and inability to afford medications, for more than 25% of patients in the initial pilot. Clinicians then provided referrals to community resources for 86% of patients who requested assistance. Notably, only 22% of patients who reported a social need requested assistance, which may indicate a cyclical nature of social need (having lower resources at specific times of the month, for example) or could mean that clinicians need to take a more active role in giving patients information, instead of waiting for them to ask for help.