Frequency of attendance at religious services and mortality in a U.S. national cohort.

Consideration of religion and spirituality has recently found a place in curricula of many American medical schools (1). Justification for this development rests partly on studies showing that spirituality and religion continue to play important roles in the subjective well being of many patients in the United States (2–7). Yet, critics have decried this movement as an “unholy alliance” (8). In part, their criticism rests on the lack of scientific consensus as to whether and by what mechanism spirituality or religion affects the physical health of Americans, conflicting results having appeared in the recent literature. For example, studies found an apparent protective effect of frequent attendance at religious services at baseline on subsequent mortality in both a California county and a U.S. national cohort of adults (9, 10). However, a multicenter study of elderly cohorts in four American cities found an effect of frequent attendance on mortality in only two of the sites and concluded that any apparent effect was spurious (11). Given this controversy, additional attempts to replicate the findings are appropriate. Religious affiliation, attendance at religious services, and other religious behavior is more prevalent in the United States, a nation in which most persons identify their religion as Christian, than in most other industrialized nations (12). Lack of religious participation has been suggested as a “fundamental cause” of mortality similar to low socioeconomic status (13). Possible mechanisms for an inverse association between participation in the activities of a religious institution and mortality have been discussed at length elsewhere (14, 15). The religion of the majority of American believers (Christianity) combines a positive worldview, social support, healthy lifestyle, and uplifting and calming ritual, all of which are hypothesized to have positive health effects. In U.S. studies, evidence is growing that greater public religiousness as indicated by a high frequency of attendance at religious services is associated with beneficial health behaviors (e.g., smoking avoidance, having a personal physician), increased social integration and support received or provided, improved coping with stressful life events, reduced depression, and positive emotions leading to health-promoting physiological effects of decreased chronic sympathoadrenal activation, improved immune function, and less chronic inflammation (13, 16–22). Some researchers suggest more proximate affects of ritual on psychophysiological pathways (23). Several small studies were consistent with some of the effect of attendance on mortality being mediated by health behaviors, and inflammation, but little by religious or nonreligious social support, personality, mental health, private religious activity or fatalism (19, 23, 24). One recent study suggested that providing rather than receiving support from fellow congregants was associated with lower mortality in the elderly (16). Other highly prevalent, secular, voluntary activities such as sports following are unlikely to offer such a combination of health promoting effects, although this is an area still under study. We further test the hypothesis of an independent, inverse association of frequency of attendance at religious services with mortality in the U.S. general population, a population identifying predominantly with the Christian religion. We analyzed newly available data on mortality in a unique national health examination and follow-up survey conducted with scientific sampling and state-of-the-art interviewing, examination and laboratory methods. No other previous national examination survey included any measure of religiousness.