This was an interesting read (ungated): Different Perspectives for Assigning Weights to Determinants of Health, by Bridget C. Booske, Jessica K. Athens, David A. Kindig, Hyojun Park, and Patrick L. Remington.
The paper begins with a very nice historical perspective that summarizes the leading causes of death and morbidity in the US over the past century, from the “sanitary revolution” beginning in the 1930s to the “social and economic determinants” that have been more recently recognized.
Then, there is a review of the literature that “has clearly established the individual importance of environmental, clinical care, health behaviors, and social and economic factors as determinants of health.”
An oft cited McGinnis et al (2002) paper states: “…using the best available estimates, the impacts of various domains on early deaths in the U.S. distribute roughly as follows: genetic predispositions, about 30%; social circumstances, 15%; environmental exposures, 5%; behavioral patterns, 40%; and shortfalls in medical care, 10%”. […]
However, some caveats should be noted:
1) The “long standing estimate” of 10% for medical care is actually based on “expert” estimates of the contribution of health care system deficiencies to total mortality; (DHHS, 1980);
2) The estimates for medical care represent the contribution of medical care deficiencies to early deaths, rather than the positive contributions of medical care to avoiding mortality;
3) The estimates represent contributions to early death and do not address contributions to other important health outcomes, such as health-related quality of life; and
4) These estimates do not fully reflect the important interrelationships between the determinant categories.
Some investigators have examined single determinants of mortality; for example, Bunker estimated that 3 of the 7.5 years of life expectancy that were gained after 1950 were due to medical care (1994). Others attribute much of the gain (58%) in life-years to primary prevention or reductions in population risk factors such as smoking, cholesterol, and blood pressure (Unal et al., 2005). More recently, Cutler and others (2006) assigned a 50% weight to medical care, while also carrying out sensitivity analysis from 25% to 75%. Wilper et al. (2009) recently updated previous IOM figures, estimating that about 45,000 or 8% of deaths among 18-64 year olds were due to lack of health insurance.
Wolff and colleagues (2007) have estimated that correcting disparities in education-associated mortality rates would have averted eight times more deaths than those attributable to medical advances between 1996 and 2002. One of the most precise studies, which controlled for many other possible explanations, showed a 1- 3% reduction in mortality rates for each year of additional schooling (Elo and Preson 1996).
Looking at two determinant categories, using longitudinal data from the Americans’ Changing Lives survey, Lantz and colleagues (2001) found that four common health risk behaviors (smoking, physical activity, alcohol consumption, and body mass index) had only modest impact in predicting functional status and self-rated health in low income populations after controlling for socioeconomic factors; they concluded that “risk behaviors are not the dominating mediating mechanism for socioeconomic health differences.” Similar results had also been found using mortality as an outcome (Lantz et al 1998).
Since it is ungated, I won’t provide full references for the papers cited above. It’s worth reading in full anyway.