Thursday 22 March 2018

Is there a link between religion and mortality?

Attending a religious service more than once per week was associated with a 33pc lower all-cause mortality
Attending a religious service more than once per week was associated with a 33pc lower all-cause mortality

Patricia Casey

Reading Twitter it is tempting to think that there is a wave of religious scepticism extending throughout the Western world and that for most, religion is a dying and irrelevant sideline. Words like 'superstition', 'irrationality' and 'delusion' are frequently tweeted by the critics of religion.

Lurking behind this superficial and often angry analysis, in the past decade there has been a major increase in research into the role religion plays in health.

Harvard University has recently published two such research papers, from research group that include epidemiologists (those who study the prevalence of disease), psychiatrists and public health specialists. The papers appeared in June , in the prestigious Journal of the American Medical Association (JAMA) Internal Medicine and JAMA Psychiatry, respectively.

As with quality journals, JAMA publications are among the most stringently peer-reviewed and complex statistical analyses. The discussions of the implications of the research are rigorous.

These papers are studies of the association between mortality and attendance at religious services. One focuses on mortality from physical illness, such as heart disease, cancer etc, and the second focuses on suicide. The lead author and researcher is an epidemiologist, Professor Tyler Vanderweele.

These studies overcome some of the flaws in many of the other investigations on mortality and correct for relevant variables such as depression, social supports and others. They also attempt to identify some of the mediators of the relationship between religion and mortality.

In the first study, attendance at religious services was assessed by questionnaire from 1992 through to June 2012. The subjects were 74,534 nurses, hence the title the Nurses' Health Study. They were free of cardiovascular disease and cancer at baseline. Confounders such as dietary factors and alcohol intake were among the many that were controlled for.

Among participants, between the ages of 30 and 55, there were 13,537 deaths, including 2,721 due to heart disease, and 4,479 to cancer. After controlling for risk factors, attending a religious service more than once per week was associated with a 33pc lower all-cause mortality compared with women who had never attended religious services: for those with cardiovascular deaths the reduction was 27pc and for cancer mortality 21pc.

Depressive symptoms, smoking, social support, and optimism were potentially important mediators of this relationship.

Another study on the relationship between church attendance and suicide on the same cohort of subjects (between 1992 and 1996) found that Catholic women were 20 times less likely to die by suicide compared to those never attending, while Protestant women were three times less.

This religious disparity in relation to suicide was identified even by Emile Durkheim, the Father of Sociology, in his 1897 book La Suicide.

Both of these studies raise interesting questions and the authors are at pains to point out that they should not be ignored, but that they should become part of the iterative nature of the scientific method. One question, when answered, raises another question that should be studied.

An invited commentary on each of these studies noted that attendance at religious services is clearly associated with lower risk of mortality. One asks what possible mechanism may contribute to this association. "Is attendance at religious services in some way associated with health habits critical to longevity that are not considered in this study?"

Another points out that this study clearly points to the importance of taking a religious history from our patients, but that the results do not imply that healthcare professionals should "prescribe" attendance at religious services.

The importance of these findings is for those who already hold religious beliefs, so that attendance at services could be encouraged as a form of meaningful social participation. The authors and commentators also point out that the results of these particular studies cannot be generalised to other groups. Thus they are applicable only to professional women in the middle years of life.

Studies of this quality need to be replicated in other groups, for example middle-aged men and young men, so that definitive information can inform our clinical work and our discussion of certain aspects of religion. Who said religion could not be studied scientifically?

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