A more recent time series (1985-95) analysis with 18 OECD countries examined the relationship between the strength of primary care and mortality, while controlling for other possible influences such as Gross Domestic Product per capita, total physicians per 1000 population, percentage of elderly people, average number of ambulatory care visits, per capita income, and alcohol and tobacco consumption.

The stronger the primary care orientation in the country, the lower the all-cause mortality, all-cause premature mortality, and cause-specific mortality from asthma and bronchitis, emphysema and pneumonia, cardiovascular disease, and heart disease.

Source: Macinko J, Starfield B, Shi L. The contribution of primary care systems to health outcomes within Organization for Economic Cooperation and Development (OECD) countries, 1970-1998. Health Serv Res 2003; 38(3):831-865.