Religion, spirituality, and medicine
Authors: RP Sloan, E Bagiella, T Powell
Journal: The Lancet (1999)

Religion and science share a complex history as well as a complex present. At various times worldwide, medical and spiritual care was dispensed by the same person. At other times, passionate (even violent) conflicts characterised the association between religion and medicine and science. As interest in alternative and complementary medicine has grown, the notion of linking religious and medical interventions has become widely popular, especially in the USA. For many people, religious and spiritual activities provide comfort in the face of illness. However, as US medical schools increasingly offer courses in religion and spirituality1Levin JS Larson DN Puchalski CM Religion and spirituality in medicine: research and education.JAMA. 1997; 278: 792-793Crossref PubMed Scopus (160) Google Scholar and as reports continue to indicate interest in this subject among both physicians and the general public, it is essential to examine how, if at all, medicine should address these issues. Here, in a comprehensive, though not systematic, review of the empirical evidence and ethical issues we make an initial attempt at such an examination. In a recent poll of 1000 US adults, 79% of the respondents believed that spiritual faith can help people recover from disease, and 63% believed that physicians should talk to patients about spiritual faith.2McNichol T The new faith in medicine.USA Today. April 7, 1996; : 4Google Scholar Recent articles in such US national newspapers as the Atlanta Constitution, Washington Post, Chicago Tribune, and USA Today report that religion can be good for your health. A new magazine, Spirituality and Health, edited by the former editor of Harvard Business Review, has begun publication. Eisenberg and colleagues, in a widely cited article on unconventional therapies, noted that 25% of all respondents reported using prayer as medical therapy.3Eisenberg DM Kessler RC Foster C Norlock FE Calkins DR Delbanco TL Unconventional medicine in the United States: prevalence, costs, and patterns of use.N Engl J Med. 1993; 328: 246-252Crossref PubMed Scopus (3662) Google Scholar King and Bushwick4King DE Bushwick B Beliefs and attitudes of hospital inpatients about faith healing and prayer.J Family Practice. 1994; 39: 349-352PubMed Google Scholar reported that 48% of hospital inpatients wanted their physicians to pray with them.4King DE Bushwick B Beliefs and attitudes of hospital inpatients about faith healing and prayer.J Family Practice. 1994; 39: 349-352PubMed Google Scholar Within the medical community, there is also considerable interest. Meetings sponsored by the US National Institute of Aging, the National Center for Medical Rehabilitation Research,5Marwick C Should physicians prescribe prayer for health? Spiritual aspects of well-being considered.JAMA. 1995; 273: 1561-1562Crossref PubMed Google Scholar and the Mind/Body Medical Institute, Beth Israel Deaconess Hospital, Boston, have drawn large, enthusiastic audiences. Nearly 30 US medical schools include in their curricula courses on religion, spirituality, and health.1Levin JS Larson DN Puchalski CM Religion and spirituality in medicine: research and education.JAMA. 1997; 278: 792-793Crossref PubMed Scopus (160) Google Scholar Of 296 physicians surveyed during the October, 1996, meeting of the American Academy of Family Physicians, 99% were convinced that religious beliefs can heal, and 75% believed that prayers of others could promote a patient's recovery. Benson writes that faith in God has a health-promoting effect.6Benson H Timeless Healing. Fireside, New York1996Google Scholar Larson and Matthews argue for spiritual and religious interventions in medical practice, hope that the "wall of separation" between medicine and religion will be torn down,7Matthews DA Larson DB Faith and medicine: reconciling the twin traditions of healing.Mind/Body Medicine. 1997; 2: 3-6Google Scholar and assert that "the medicine of the future is going to be prayer and Prozac" (8Sides H The calibration of belief.New York Times Magazine. 1997; : 93-95Google Scholar, p 85). In an American Medical Association publication, Matthews and colleagues recommend that clinicians ask "what can I do to support your faith or religious commitment?" to patients who respond favourably to questions about whether religion or faith are "helpful in handling your illness'.9Matthews DA McCullough ME Larson DB Koenig HG Swyers JP Milano MG Religious commitment and health status.Arch Family Medicine. 1998; 7: 118-124Crossref PubMed Scopus (280) Google Scholar In many studies, religion, as a putative antecedent to health outcomes, has been measured in several ways—eg, assessment of religious behaviours, such as frequency of church attendance or prayer; dimensions of religious experience, such as the comfort it may provide; and health differences as a function of differences in religious denomination or degree of religious orthodoxy. In addition, health outcomes vary considerably—eg, physical disease outcomes, mental health outcomes, and health behaviours. Here, we consider methodological issues that pertain to studies of physical disease outcomes. Confounders such as behavioural and genetic differences and stratification variables such as age, sex, education, ethnicity, socioeconomic status, and health status may have an important role in the association between religion and health. Failure to control for these factors can lead to a biased estimation of this association. Multivariate methods allow estimation of the magnitude of the association between religious variables and health outcomes while controlling for the effects of other variables. However, use of these methods requires complete presentation of the results—at least the coefficients and corresponding confidence intervals for all the variables in the statistical model. Reports that fail to do this are incomplete and may be misleading. Attempts to assess the effect of degree of religiousness on health outcomes show this. Increased religious devotion, assessed as service as a Roman Catholic priest,10Michalek AM Mettlin C Priore RL Prostate cancer mortality among Catholic priests.J Surg Oncol. 1981; 17: 129-133Crossref PubMed Scopus (10) Google Scholar nun,11Timio M Lippi G Venanzi S et al.Blood pressure trend and cardiovascular events in nuns in a secluded order: a 30-year follow-up study.Blood Pressure. 1997; 6: 81-87Crossref PubMed Scopus (67) Google Scholar Morman priest,12Gardner JW Lyon JL Cancer in Utah Mormon men by lay priesthood level.Am J Epidemiol. 1982; 116: 243-257PubMed Google Scholar, or Trappist or Benedictine monk,13de Gouw HWFM Westndrop RGJ Kunst AE Mackenbach JP Vandenbrouke JP Decreased mortality among contemplative monks in the Netherlands.Am J Epidemiol. 1996; 141: 771-775Google Scholar is associated with reductions in morbidity and mortality. These cases, however, were selected for study precisely because they are inclined to stricter adherence to codes of conduct that proscribe behaviours associated with risk (eg, smoking, alcohol consumption, sexual activity, psychosocial stress, and in some cases, consumption of meat). In a series of studies from Israel,14Friedlander Y Kark JD Stein Y Religious orthodoxy and myocardial infarction in Jerusalem: a case control study.Int J Cardiol. 1986; 10: 33-41Summary Full Text PDF PubMed Scopus (49) Google Scholar, 15Goldbourt U Yaari S Medalie JH Factors predictive of long-term coronary heart disease mortality among 10 059 male Israeli civil servants and municipal employees.Cardiology. 1993; 82: 100-121Crossref PubMed Scopus (199) Google Scholar, 16Kark JD Shemi G Friedlander Y Martin O Manor O Blondheim SH Does religious observance promote health? Mortality in secular and religious kibbutzim in Israel.AJPH. 1996; 86: 341-346Crossref PubMed Scopus (167) Google Scholar religiousness, measured as religious orthodoxy, was also shown to confer health benefits. However, one of these14Friedlander Y Kark JD Stein Y Religious orthodoxy and myocardial infarction in Jerusalem: a case control study.Int J Cardiol. 1986; 10: 33-41Summary Full Text PDF PubMed Scopus (49) Google Scholar was a case-control study, the deficiencies of which are widely known. In another,15Goldbourt U Yaari S Medalie JH Factors predictive of long-term coronary heart disease mortality among 10 059 male Israeli civil servants and municipal employees.Cardiology. 1993; 82: 100-121Crossref PubMed Scopus (199) Google Scholar a multivariate model that predicted mortality from coronary heart disease included standard risk factors but omitted religion, and no information on risk-ratio or confidence intervals or even level of statistical significance was provided. Finally, in a study matching secular and religious Kibbutzim according to location, use of the same regional hospital, and members older than 40 years, all-cause mortality was significantly greater among members of the secular Kibbutzim. However, the strategy of matching ensures equivalence of groups only on the matched variables. As a consequence, the groups differed with respect to dietary habits, smoking, blood cholesterol concentrations, and marital status, with the secular group having greater risk, as the authors themselves report. The multivariate analysis of mortality did not control for these factors. Control for confounding and other covariates also affects studies that report that religious behaviours and experiences influence health outcomes. In some studies with large databases, this problem can be addressed. Both the Alameda County Study and the Tecumseh Community Health Study showed that frequency of attendance at religious services was inversely associated with mortality.17House JS Robbins C Metzner HL The association of social relationships and activities with mortality: prospective evidence from the Tecumseh Community Health Study.Am J Epidemiol. 1982; 116: 123-140PubMed Google Scholar, 18Strawbridge WJ Cohen RD Shema SJ Kaplan GA Frequent attendance at religious services and mortality over 28 years.AJPH. 1997; 87: 957-961Crossref PubMed Scopus (511) Google Scholar However, after control for all relevant covariates, this relation held only for women. In another large study, attendance at religious services was associated with increased functional capacity in the elderly19Idler EL Kasl SV Religion among disabled and nondisabled persons II: Attendance at religious services as a predictor of the course of disability.J Gerontol. 1997; 52B: S306-S316Crossref Scopus (276) Google Scholar but after control for appropriate covariates, this relation held for only 3 of the 7 years in which outcome data were collected. There was no effect on mortality.20Idler EL Kasl SV Religion, disability, depression, and the timing of death.Am J Sociol. 1992; 97: 1052-1079Crossref Google Scholar In a smaller study, religiousness predicted mortality in the elderly poor but only among those in poor health.21Zuckerman DM Kasl SV Ostfeld AM Psychosocial predictors of mortality among the elderly poor.Am J Epidemiol. 1984; 119: 410-423PubMed Google Scholar In many other studies, inadequate control for important covariates points to significant findings when none may exist. For example, Pressman and colleagues22Pressman P Lyons JS Larson DB Strain JJ Religious belief, depression and ambulation status in elderly women with broken hips.Am J Psychiatry. 1990; 147: 758-760Crossref PubMed Scopus (203) Google Scholar reported that among elderly women after surgical repair of broken hips, religiousness was associated with better ambulation status at discharge. Although the analysis controlled for severity of health condition, it did not control for age, a critical variable when studying functional capacity in the elderly. In some cases, problems of interpretation arise not so much in the original research but rather in secondary sources. A case in point is a report by Comstock and Partridge,23Comstock GW Partidge KB Church attendance and health.J Chronic Dis. 1972; 225: 665-672Summary Full Text PDF Scopus (210) Google Scholar frequently cited as showing a positive association between church attendance and health. However, as Comstock himself later reported, this finding was probably due to failure to control for the important covariate of functional capacity: people with reduced capacity (and poorer health) were less likely to go to church.24Comstock GW Tonascia JA Education and mortality in Washington County, Maryland.J Health Soc Behav. 1977; 18: 54-61Crossref Scopus (84) Google Scholar This latter study is rarely cited. Similarly, Koenig reports that a study by Colantonio and colleagues25Colantonio A Kask SV Ostfeld AM Depressive symptoms and other psychosocial factors as predictors of stroke in the elderly.Am J Epidemiol. 1992; 136: 884-894Crossref PubMed Scopus (134) Google Scholar "found lower rates of stroke in persons who attended religious services at least once per week …".26Koenig HG Is religion good for your health? Haworth Pastoral Press, Binghamton, NY1997Google Scholar However, this was only the case for the univariate analysis and the effect disappeared after covariates such as levels of physical function were added to the analysis. Levin, in a review of a review, reported that 22 of 27 studies of religious attendance and health showed a significant positive relation,27Levin JS Religion and health: is there an association, is it valid, and is it causal?.Soc Sci Med. 1994; 38: 1475-1482Crossref PubMed Scopus (399) Google Scholar despite his own previous assertion that associations between attendance and health are highly questionable because this research is characterised by numerous methodological problems including the failure to adjust for confounders and covariates.28Levin JS Vanderpool HY Is frequent religious attendance really conducive to better health?: toward an epidemiology of religion.Soc Sci Med. 1987; 24: 589-600Crossref PubMed Scopus (250) Google Scholar Finally, many studies evaluate differences in health indicators as a function of religious denomination (eg, 29Walden RT Schaefer LE Lemon FR Sunshine A Wynder EL Effect of environment on the serum cholesterol-triglyceride distribution among Seventh-day Adventists.Am J Med. 1964; 36: 269-276Summary Full Text PDF PubMed Scopus (29) Google Scholar, 30Rasanen J Kauhanen J Lakka TA Kaplan GA Salonen JT Religious affiliation and all-cause mortality: a prospective population study in middle-aged men in eastern Finland.Int J Epidemiol. 1996; 25: 1244-1249Crossref PubMed Scopus (22) Google Scholar, 31Lyon JL Gardner K Gress RE Cancer incidence among Mormons and non-Mormons in Utah (United States) 1971–85.Cancer Causes Control. 1994; 5: 149-156Crossref PubMed Scopus (40) Google Scholar). However, they are generally conducted precisely because religious groups differ on risk behaviours such as smoking and alcohol consumption or on genetic heritage. Many studies on religion and health fail to make an adjustment for the greater likelihood of finding a statistically significant result when conducting multiple statistical tests. For example, one study reported that religious attendance was inversely associated with high concentrations of interleukin-6 in the elderly.32Koenig HG Cohen HG George LK Hays JC Larson DB Blazer DG Attendance at religious services, interleukin-6, and other biological parameters of immune function in older adults.Int J Psychiatry Med. 1997; 27: 233-250Crossref PubMed Scopus (187) Google Scholar However, interleukin-6 was one of eight outcome variables and there was no attempt to control for multiple comparisons, as the authors themselves reported. In a retrospective study,33Levin JS Lyons JS Larson DB Prayer and health during pregnancy: Findings from the Galveston Low birthweight Survey.Southern Med J. 1993; 86: 1022-1027Crossref PubMed Scopus (23) Google Scholar the associations between frequency of prayer and six items measuring subjective health were examined. Analyses of variance were conducted on each of these six perceptions of health and three revealed effects of frequency of prayer at the 0·05 level of statistical significance. In such studies, adjustments of α levels to control for such multiple comparisons would render these findings non-significant. There are similar problems in the only published randomised clinical trial.34Byrd RC Positive therapeutic effects of intercessory prayer in a coronary care unit population.Southern Med J. 1988; 81: 826-829Crossref PubMed Scopus (445) Google Scholar In this double-blind study, patients in a coronary-care unit (CCU) were assigned randomly either to standard care or to daily intercessory prayer ministered by three to seven born-again Christians. 29 outcome variables were measured, and on six the prayer group had fewer newly diagnosed ailments. However, the six significant outcomes were not independent: the prayer group had fewer cases of newly diagnosed heart failure and of newly prescribed diuretics and fewer cases of newly diagnosed pneumonia and of newly prescribed antibiotics. There was no control for multiple comparisons, a fact recognised by the author. To address this issue, "multivariant" analysis was conducted but the results were not presented, except for a p value for overall model. Published work on religion and health lacks consistency, even among well-conducted studies. For example, while Idler and Kasl found some effects of religious attendance on functional capacity in the elderly, measures of "religious involvement", an index of the "private, reflective" aspects of religion, were not associated with any health outcome. Neither church attendance nor religious involvement was associated with lower mortality.20Idler EL Kasl SV Religion, disability, depression, and the timing of death.Am J Sociol. 1992; 97: 1052-1079Crossref Google Scholar However, in two other large studies,17House JS Robbins C Metzner HL The association of social relationships and activities with mortality: prospective evidence from the Tecumseh Community Health Study.Am J Epidemiol. 1982; 116: 123-140PubMed Google Scholar, 18Strawbridge WJ Cohen RD Shema SJ Kaplan GA Frequent attendance at religious services and mortality over 28 years.AJPH. 1997; 87: 957-961Crossref PubMed Scopus (511) Google Scholar church attendance was associated with lower mortality, but only in women. Inconsistencies also arise within studies not based on large epidemiological samples. For instance, when each individual item from the scale of religiousness used by Idler and Kasl, was used in another study, "religious comfort and strength" was significantly associated with lower mortality after cardiac surgery in the elderly even after control for relevant confounders.35Oxman TE Freeman DH Manheimer ED Lack of social participation or religious strength and comfort as risk factors after cardiac surgery in the elderly.Psychosomatic Med. 1995; 57: 5-15Crossref PubMed Scopus (395) Google Scholar However, the other items from this scale, including religious attendance, did not predict mortality. Moreover, when the entire scale was used, the relation between religion and mortality failed to reach significance. Byrd34Byrd RC Positive therapeutic effects of intercessory prayer in a coronary care unit population.Southern Med J. 1988; 81: 826-829Crossref PubMed Scopus (445) Google Scholar reported an advantage in hospital course for the group receiving prayer compared with the control group. However, the groups did not differ in days in the CCU, length of stay in hospital, and number of discharge medications. While total cholesterol concentrations were lower across all age groups for a cohort of Seventh Day Adventists (SDAs) than in age-matched healthy New York City men and women, suggesting a lower risk of coronary heart disease among SDAs, serum triglycerides of the SDA men in the coronary-prone age range (>32 years) were 19% higher than in the controls, which suggests the opposite.29Walden RT Schaefer LE Lemon FR Sunshine A Wynder EL Effect of environment on the serum cholesterol-triglyceride distribution among Seventh-day Adventists.Am J Med. 1964; 36: 269-276Summary Full Text PDF PubMed Scopus (29) Google Scholar To some degree, lack of consistency is characteristic of an evolving field and may be the product of differences in study design, definitions of religious and spiritual variables, and outcome variables. The absence of specific definitions of religious and spiritual activity is an important problem, since many of the studies to which we refer define these activities differently. Published research would be substantially improved with better definitions of these terms. However, inconsistency in the empirical findings makes it difficult to support recommendations for clinical interventions. Health professionals, even in these days of consumer advocacy, influence patients by virtue of their medical expertise. When doctors depart from areas of established expertise to promote a non-medical agenda, they abuse their status as professionals. Thus, we question inquiries into a patient's spiritual life in the service of making recommendations that link religious practice with better health outcomes. Is it really appropriate, as Matthews and colleagues9Matthews DA McCullough ME Larson DB Koenig HG Swyers JP Milano MG Religious commitment and health status.Arch Family Medicine. 1998; 7: 118-124Crossref PubMed Scopus (280) Google Scholar recommend, for a physician to ask patients what he or she can do to support their faith or religious commitment? A second ethical consideration involves the limits of medical intervention. If religious or spiritual factors were shown convincingly to be related to health outcomes, they would join such factors as socioeconomic status and marital status,38Powell T Regligion, race, and reason.J Clin Ethics. 1995; 6: 73-77PubMed Google Scholar already well established as significantly associated with health. Although physicans may choose to engage patients in discussions of these matters to understand them better, we would consider it unacceptable for a physician to advise an unmarried patient to marry because the data show that marriage is associated with lower mortality.38Powell T Regligion, race, and reason.J Clin Ethics. 1995; 6: 73-77PubMed Google Scholar This is because we generally regard financial and marital matters as private and personal, not the business of medicine, even if they have health implications. There is an important difference between "taking into account" marital, financial, or religious factors and "taking them on" as the objects of interventions. A third ethical problem concerns the possibility of doing harm. Linking religious activities and better health outcomes can be harmful to patients, who already must confront age-old folk wisdom that illness is due to their own moral failure.37Gould SJ The mismeasure of man. Norton, New York1981Google Scholar Within any individual religion, are the more devout adherents "better" people, more deserving of health than others? If evidence showed health advantages of some religious denominations over others, should physicians be guided by this evidence to counsel conversion? Attempts to link religious and spiritual activities to health are reminiscent of the now discredited research suggesting that different ethnic groups show differing levels of moral probity, intelligence, or other measures of social worth.37Gould SJ The mismeasure of man. Norton, New York1981Google Scholar Since all human beings, devout or profane, ultimately will succumb to illness, we wish to avoid the additional burden of guilt for moral failure to those whose physical health fails before our own. Some practitioners who link faith and medical practice do so appropriately, and in ways that do not depend on utilitarian expectations of better health. For instance, devout health professionals may view their work as an extension of their religious beliefs. Such physicians may or may not choose to share their opinions with patients. However, some patients and doctors may be aware of a common faith. There is no ethical objection to co-worshippers discussing medical issues in the context of a shared faith. Indeed, a thorough understanding of a patient's religious values can be extremely important in discussing critical medical issues, such as care at the end of life. Irrespective of the practitioner's religion, respectful attention must be paid to the impact of religion on the patient's decisions about health care.38Powell T Regligion, race, and reason.J Clin Ethics. 1995; 6: 73-77PubMed Google Scholar An especially poignant example of the devout practitioner who appropriately notes connections between illness, recovery, and prayers of thanks is provided by Prager, in describing a serious illness in his son.41 Prager does not suggest that his son recovers function because he is faithful, but rather teaches how the faithful may give thanks for recovery. Such connections between faith and health are valuable because they are sensitive to all aspects of the patient's experience, yet in no way depend on spurious claims about scientific data. Even in the best studies, the evidence of an association between religion, spirituality, and health is weak and inconsistent.