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. 2001 Dec;55(12):878–884. doi: 10.1136/jech.55.12.878

Are the effects of psychosocial exposures attributable to confounding? Evidence from a prospective observational study on psychological stress and mortality

J Macleod 1, S Davey 1, P Heslop 1, C Metcalfe 1, D Carroll 1, C Hart 1
PMCID: PMC1731800  PMID: 11707481

Abstract

STUDY OBJECTIVES—To examine the association between perceived psychological stress and cause specific mortality in a population where perceived stress was not associated with material disadvantage.
DESIGN—Prospective observational study with follow up of 21 years and repeat screening of half the cohort five years from baseline. Measures included perceived psychological stress, coronary risk factors, and indices of lifecourse socioeconomic position.
SETTING—27 workplaces in Scotland.
PARTICIPANTS—5388 men (mean age 48 years) at first screening and 2595 men at second screening who had complete data on all measures.
MAIN OUTCOME MEASURES—Hazard ratios for all cause mortality and mortality from cardiovascular disease (ICD9 390-459), coronary heart disease (ICD9 410-414), smoking related cancers (ICD9 140, 141, 143-9, 150, 157, 160-163, 188 and 189), other cancers (ICD9 140-208 other than smoking related), stroke (ICD9 430-438), respiratory diseases (ICD9 460-519) and alcohol related causes (ICD9 141, 143-6, 148-9, 150, 155, 161, 291, 303, 571 and 800-998).
RESULTS—At first screening behavioural risk (higher smoking and alcohol consumption, lower exercise) was positively associated with stress. This relation was less apparent at second screening. Higher stress at first screening showed an apparent protective relation with all cause mortality and with most categories of cause specific mortality. In general, these estimates were attenuated on adjustment for social position. This pattern was also seen in relation to cumulative stress at first and second screening and with stress that increased between first and second screening. The pattern was most striking with regard to smoking related cancers: relative risk high compared with low stress at first screening, age adjusted 0.64 (95% CI 0.42, 0.96), p for trend 0.016, fully adjusted 0.69 (95% CI 0.45, 1.06), p for trend 0.10; high compared with low cumulative stress, age adjusted 0.69 (95% CI 0.44, 1.09), p for trend 0.12, fully adjusted 0.76 (95% CI 0.48, 1.21), p for trend 0.25; increased compared with decreased stress, age adjusted 0.65 (95% CI 0.40, 1.06), p for trend 0.09, fully adjusted 0.65 (95% CI 0.40, 1.06), p for trend 0.08.
CONCLUSIONS—This implausible protective relation between higher levels of stress, which were associated with increased smoking, and mortality from smoking related cancers, was probably a product of confounding. Plausible reported associations between psychosocial exposures and disease, in populations where such exposures are associated with material disadvantage, may be similarly produced by confounding, and of no causal significance.


Keywords: socioeconomic differentials; psychosocial factors; mortality

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Selected References

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  1. Alterman T., Shekelle R. B., Vernon S. W., Burau K. D. Decision latitude, psychologic demand, job strain, and coronary heart disease in the Western Electric Study. Am J Epidemiol. 1994 Mar 15;139(6):620–627. doi: 10.1093/oxfordjournals.aje.a117051. [DOI] [PubMed] [Google Scholar]
  2. Bosma H., Marmot M. G., Hemingway H., Nicholson A. C., Brunner E., Stansfeld S. A. Low job control and risk of coronary heart disease in Whitehall II (prospective cohort) study. BMJ. 1997 Feb 22;314(7080):558–565. doi: 10.1136/bmj.314.7080.558. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bosma H., Schrijvers C., Mackenbach J. P. Socioeconomic inequalities in mortality and importance of perceived control: cohort study. BMJ. 1999 Dec 4;319(7223):1469–1470. doi: 10.1136/bmj.319.7223.1469. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bosma H., van de Mheen H. D., Mackenbach J. P. Social class in childhood and general health in adulthood: questionnaire study of contribution of psychological attributes. BMJ. 1999 Jan 2;318(7175):18–22. doi: 10.1136/bmj.318.7175.18. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Brunner E. Stress and the biology of inequality. BMJ. 1997 May 17;314(7092):1472–1476. doi: 10.1136/bmj.314.7092.1472. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bygren L. O., Konlaan B. B., Johansson S. E. Attendance at cultural events, reading books or periodicals, and making music or singing in a choir as determinants for survival: Swedish interview survey of living conditions. BMJ. 1996 Dec 21;313(7072):1577–1580. doi: 10.1136/bmj.313.7072.1577. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Chapman J. M., Reeder L. G., Massey F. J., Jr, Borun E. R., Picken B., Browning G. G., Coulson A. H., Zimmerman D. H. Relationships of stress, tranquilizers, and serum cholesterol levels in a sample population under study for coronary heart disease. Am J Epidemiol. 1966 May;83(3):537–547. doi: 10.1093/oxfordjournals.aje.a120605. [DOI] [PubMed] [Google Scholar]
  8. Cheng Y., Kawachi I., Coakley E. H., Schwartz J., Colditz G. Association between psychosocial work characteristics and health functioning in American women: prospective study. BMJ. 2000 May 27;320(7247):1432–1436. doi: 10.1136/bmj.320.7247.1432. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Cohen S., Kamarck T., Mermelstein R. A global measure of perceived stress. J Health Soc Behav. 1983 Dec;24(4):385–396. [PubMed] [Google Scholar]
  10. Davey Smith G., Frankel S., Yarnell J. Sex and death: are they related? Findings from the Caerphilly Cohort Study. BMJ. 1997 Dec 20;315(7123):1641–1644. doi: 10.1136/bmj.315.7123.1641. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Davey Smith G., Hart C., Hole D., MacKinnon P., Gillis C., Watt G., Blane D., Hawthorne V. Education and occupational social class: which is the more important indicator of mortality risk? J Epidemiol Community Health. 1998 Mar;52(3):153–160. doi: 10.1136/jech.52.3.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Everson S. A., Goldberg D. E., Kaplan G. A., Cohen R. D., Pukkala E., Tuomilehto J., Salonen J. T. Hopelessness and risk of mortality and incidence of myocardial infarction and cancer. Psychosom Med. 1996 Mar-Apr;58(2):113–121. doi: 10.1097/00006842-199603000-00003. [DOI] [PubMed] [Google Scholar]
  13. Everson S. A., Kauhanen J., Kaplan G. A., Goldberg D. E., Julkunen J., Tuomilehto J., Salonen J. T. Hostility and increased risk of mortality and acute myocardial infarction: the mediating role of behavioral risk factors. Am J Epidemiol. 1997 Jul 15;146(2):142–152. doi: 10.1093/oxfordjournals.aje.a009245. [DOI] [PubMed] [Google Scholar]
  14. Greenwood D. C., Muir K. R., Packham C. J., Madeley R. J. Coronary heart disease: a review of the role of psychosocial stress and social support. J Public Health Med. 1996 Jun;18(2):221–231. doi: 10.1093/oxfordjournals.pubmed.a024483. [DOI] [PubMed] [Google Scholar]
  15. Haines A., Cooper J., Meade T. W. Psychological characteristics and fatal ischaemic heart disease. Heart. 2001 Apr;85(4):385–389. doi: 10.1136/heart.85.4.385. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Hart C. L., Smith G. D., Hole D. J., Hawthorne V. M. Alcohol consumption and mortality from all causes, coronary heart disease, and stroke: results from a prospective cohort study of scottish men with 21 years of follow up. BMJ. 1999 Jun 26;318(7200):1725–1729. doi: 10.1136/bmj.318.7200.1725. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Haynes S. G., Levine S., Scotch N., Feinleib M., Kannel W. B. The relationship of psychosocial factors to coronary heart disease in the Framingham study. I. Methods and risk factors. Am J Epidemiol. 1978 May;107(5):362–383. doi: 10.1093/oxfordjournals.aje.a112556. [DOI] [PubMed] [Google Scholar]
  18. Hellerstedt W. L., Jeffery R. W. The association of job strain and health behaviours in men and women. Int J Epidemiol. 1997 Jun;26(3):575–583. doi: 10.1093/ije/26.3.575. [DOI] [PubMed] [Google Scholar]
  19. Hemingway H., Marmot M. Evidence based cardiology: psychosocial factors in the aetiology and prognosis of coronary heart disease. Systematic review of prospective cohort studies. BMJ. 1999 May 29;318(7196):1460–1467. doi: 10.1136/bmj.318.7196.1460. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Heslop P., Smith G. D., Carroll D., Macleod J., Hyland F., Hart C. Perceived stress and coronary heart disease risk factors: the contribution of socio-economic position. Br J Health Psychol. 2001 May;6(Pt 2):167–178. doi: 10.1348/135910701169133. [DOI] [PubMed] [Google Scholar]
  21. Kauhanen J., Kaplan G. A., Cohen R. D., Julkunen J., Salonen J. T. Alexithymia and risk of death in middle-aged men. J Psychosom Res. 1996 Dec;41(6):541–549. doi: 10.1016/s0022-3999(96)00226-7. [DOI] [PubMed] [Google Scholar]
  22. Macleod J. Mortality among elderly caregivers. JAMA. 2000 Apr 26;283(16):2105–2106. doi: 10.1001/jama.283.16.2105. [DOI] [PubMed] [Google Scholar]
  23. Marmot M. G., Bosma H., Hemingway H., Brunner E., Stansfeld S. Contribution of job control and other risk factors to social variations in coronary heart disease incidence. Lancet. 1997 Jul 26;350(9073):235–239. doi: 10.1016/s0140-6736(97)04244-x. [DOI] [PubMed] [Google Scholar]
  24. Marmot M. G. Improvement of social environment to improve health. Lancet. 1998 Jan 3;351(9095):57–60. doi: 10.1016/S0140-6736(97)08084-7. [DOI] [PubMed] [Google Scholar]
  25. Marmot M., Bobak M. International comparators and poverty and health in Europe. BMJ. 2000 Nov 4;321(7269):1124–1128. doi: 10.1136/bmj.321.7269.1124. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Orth-Gomér K., Wamala S. P., Horsten M., Schenck-Gustafsson K., Schneiderman N., Mittleman M. A. Marital stress worsens prognosis in women with coronary heart disease: The Stockholm Female Coronary Risk Study. JAMA. 2000 Dec 20;284(23):3008–3014. doi: 10.1001/jama.284.23.3008. [DOI] [PubMed] [Google Scholar]
  27. Petticrew M., Gilbody S., Sheldon T. A. Relation between hostility and coronary heart disease. Evidence does not support link. BMJ. 1999 Oct 2;319(7214):917–918. doi: 10.1136/bmj.319.7214.917. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Reeder L. G., Schrama P. G., Dirken J. M. Stress and cardiovascular health: an international cooperative study. I. Soc Sci Med. 1973 Aug;7(8):573–584. doi: 10.1016/0037-7856(73)90026-7. [DOI] [PubMed] [Google Scholar]
  29. Rosengren A., Tibblin G., Wilhelmsen L. Self-perceived psychological stress and incidence of coronary artery disease in middle-aged men. Am J Cardiol. 1991 Nov 1;68(11):1171–1175. doi: 10.1016/0002-9149(91)90189-r. [DOI] [PubMed] [Google Scholar]
  30. Schachter S., Silverstein B., Kozlowski L. T., Herman C. P., Liebling B. 4. Effects of stress on cigarette smoking and urinary pH. J Exp Psychol Gen. 1977 Mar;106(1):24–30. [PubMed] [Google Scholar]
  31. Shively C. A., Clarkson T. B. Social status and coronary artery atherosclerosis in female monkeys. Arterioscler Thromb. 1994 May;14(5):721–726. doi: 10.1161/01.atv.14.5.721. [DOI] [PubMed] [Google Scholar]
  32. Smith G. D., Dorling D. "I'm all right, John": voting patterns and mortality in England and Wales, 1981-92. BMJ. 1996 Dec 21;313(7072):1573–1577. doi: 10.1136/bmj.313.7072.1573. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Smith G. D., Harding S. Is control at work the key to socioeconomic gradients in mortality? Lancet. 1997 Nov 8;350(9088):1369–1370. doi: 10.1016/S0140-6736(05)65141-0. [DOI] [PubMed] [Google Scholar]
  34. Smith G. D., Hart C., Blane D., Gillis C., Hawthorne V. Lifetime socioeconomic position and mortality: prospective observational study. BMJ. 1997 Feb 22;314(7080):547–552. doi: 10.1136/bmj.314.7080.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Smith G. D., Phillips A. N. Confounding in epidemiological studies: why "independent" effects may not be all they seem. BMJ. 1992 Sep 26;305(6856):757–759. doi: 10.1136/bmj.305.6856.757. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Smith G. D., Phillips A. N., Neaton J. D. Smoking as "independent" risk factor for suicide: illustration of an artifact from observational epidemiology? Lancet. 1992 Sep 19;340(8821):709–712. [PubMed] [Google Scholar]
  37. Smith G. D., Shipley M., Leon D. A. Height and mortality from cancer among men: prospective observational study. BMJ. 1998 Nov 14;317(7169):1351–1352. doi: 10.1136/bmj.317.7169.1351. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Syme S. L., Balfour J. L. Explaining inequalities in coronary heart disease. Lancet. 1997 Jul 26;350(9073):231–232. doi: 10.1016/S0140-6736(05)62220-9. [DOI] [PubMed] [Google Scholar]
  39. Vahtera J., Kivimäki M., Pentti J., Theorell T. Effect of change in the psychosocial work environment on sickness absence: a seven year follow up of initially healthy employees. J Epidemiol Community Health. 2000 Jul;54(7):484–493. doi: 10.1136/jech.54.7.484. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Watson D., Pennebaker J. W. Health complaints, stress, and distress: exploring the central role of negative affectivity. Psychol Rev. 1989 Apr;96(2):234–254. doi: 10.1037/0033-295x.96.2.234. [DOI] [PubMed] [Google Scholar]
  41. Yarnold P. R., Mueser K. T. Meta-analyses of the reliability of Type A behaviour measures. Br J Med Psychol. 1989 Mar;62(Pt 1):43–50. doi: 10.1111/j.2044-8341.1989.tb02809.x. [DOI] [PubMed] [Google Scholar]

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