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. 1996 May 15;154(10):1493–1499.

Prevention. How much harm? How much benefit? 1. Influence of reporting methods on perception of benefits.

K G Marshall 1
PMCID: PMC1487820  PMID: 8624999

Abstract

Before a physician or a patient can decide whether a preventive program is worth while, each must understand the nature and degree of its benefits and the frequency and magnitude of its adverse effects. Preventive interventions can be divided into two major categories: those with infrequent or minor adverse effects and those with adverse effects that are frequent or serious. Accident prevention, avoidance of high-risk behaviour and healthy lifestyle choices such as breast-feeding and moderate exercise are associated with few adverse consequences. By contrast, screening populations for disease, risk classification for the purpose of selective preventive interventions, dietary intervention and prophylactic drug treatment may lead to more frequent and serious adverse effects. When assessing whether the benefits of a preventive intervention outweigh the harm, one must be aware that the methods used to report benefits of clinical trials may distort the reader's perception of their magnitude. The relative reduction of morbidity or mortality rate often grossly exaggerates benefits and should never be used as a basis for clinical decision making. More realistic ways of recording benefits are the absolute reduction of morbidity or mortality rate, the number of patients that need to be treated to avoid one adverse event, and the total cohort mortality rate.

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Selected References

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  1. Andersson I., Aspegren K., Janzon L., Landberg T., Lindholm K., Linell F., Ljungberg O., Ranstam J., Sigfússon B. Mammographic screening and mortality from breast cancer: the Malmö mammographic screening trial. BMJ. 1988 Oct 15;297(6654):943–948. doi: 10.1136/bmj.297.6654.943. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Andres R., Muller D. C., Sorkin J. D. Long-term effects of change in body weight on all-cause mortality. A review. Ann Intern Med. 1993 Oct 1;119(7 Pt 2):737–743. doi: 10.7326/0003-4819-119-7_part_2-199310011-00022. [DOI] [PubMed] [Google Scholar]
  3. Bergkvist L., Adami H. O., Persson I., Hoover R., Schairer C. The risk of breast cancer after estrogen and estrogen-progestin replacement. N Engl J Med. 1989 Aug 3;321(5):293–297. doi: 10.1056/NEJM198908033210505. [DOI] [PubMed] [Google Scholar]
  4. Blair S. N., Shaten J., Brownell K., Collins G., Lissner L. Body weight change, all-cause mortality, and cause-specific mortality in the Multiple Risk Factor Intervention Trial. Ann Intern Med. 1993 Oct 1;119(7 Pt 2):749–757. doi: 10.7326/0003-4819-119-7_part_2-199310011-00024. [DOI] [PubMed] [Google Scholar]
  5. Bobbio M., Demichelis B., Giustetto G. Completeness of reporting trial results: effect on physicians' willingness to prescribe. Lancet. 1994 May 14;343(8907):1209–1211. doi: 10.1016/s0140-6736(94)92407-4. [DOI] [PubMed] [Google Scholar]
  6. Bucher H. C., Weinbacher M., Gyr K. Influence of method of reporting study results on decision of physicians to prescribe drugs to lower cholesterol concentration. BMJ. 1994 Sep 24;309(6957):761–764. doi: 10.1136/bmj.309.6957.761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Burton B. K., Dillard R. G., Clark E. N. The psychological impact of false positive elevations of maternal serum alpha-fetoprotein. Am J Obstet Gynecol. 1985 Jan 1;151(1):77–82. doi: 10.1016/0002-9378(85)90428-4. [DOI] [PubMed] [Google Scholar]
  8. Colditz G. A., Hankinson S. E., Hunter D. J., Willett W. C., Manson J. E., Stampfer M. J., Hennekens C., Rosner B., Speizer F. E. The use of estrogens and progestins and the risk of breast cancer in postmenopausal women. N Engl J Med. 1995 Jun 15;332(24):1589–1593. doi: 10.1056/NEJM199506153322401. [DOI] [PubMed] [Google Scholar]
  9. Farrington P., Pugh S., Colville A., Flower A., Nash J., Morgan-Capner P., Rush M., Miller E. A new method for active surveillance of adverse events from diphtheria/tetanus/pertussis and measles/mumps/rubella vaccines. Lancet. 1995 Mar 4;345(8949):567–569. doi: 10.1016/s0140-6736(95)90471-9. [DOI] [PubMed] [Google Scholar]
  10. Habr-Gama A., Waye J. D. Complications and hazards of gastrointestinal endoscopy. World J Surg. 1989 Mar-Apr;13(2):193–201. doi: 10.1007/BF01658399. [DOI] [PubMed] [Google Scholar]
  11. Hall P. F. Rethinking risk. Can Fam Physician. 1994 Jul;40:1239-42, 1244, 1246-51. [PMC free article] [PubMed] [Google Scholar]
  12. Harris R., Leininger L. Clinical strategies for breast cancer screening: weighing and using the evidence. Ann Intern Med. 1995 Apr 1;122(7):539–547. doi: 10.7326/0003-4819-122-7-199504010-00011. [DOI] [PubMed] [Google Scholar]
  13. Hendey G. W., Votey S. R. Injuries in restrained motor vehicle accident victims. Ann Emerg Med. 1994 Jul;24(1):77–84. doi: 10.1016/s0196-0644(94)70166-0. [DOI] [PubMed] [Google Scholar]
  14. Horowitz M., Hulley S., Alvarez W., Billings J., Benfari R., Blair S., Borhani N., Simon N. News of risk for early heart disease as a stressful event. Psychosom Med. 1980 Jan;42(1):37–46. doi: 10.1097/00006842-198001000-00005. [DOI] [PubMed] [Google Scholar]
  15. Jaeschke R., Guyatt G., Shannon H., Walter S., Cook D., Heddle N. Basic statistics for clinicians: 3. Assessing the effects of treatment: measures of association. CMAJ. 1995 Feb 1;152(3):351–357. [PMC free article] [PubMed] [Google Scholar]
  16. Kamrath R. O., Plummer L. J., Sadur C. N., Adler M. A., Strader W. J., Young R. L., Weinstein R. L. Cholelithiasis in patients treated with a very-low-calorie diet. Am J Clin Nutr. 1992 Jul;56(1 Suppl):255S–257S. doi: 10.1093/ajcn/56.1.255S. [DOI] [PubMed] [Google Scholar]
  17. Kaplan J. R., Manuck S. B., Shively C. The effects of fat and cholesterol on social behavior in monkeys. Psychosom Med. 1991 Nov-Dec;53(6):634–642. doi: 10.1097/00006842-199111000-00005. [DOI] [PubMed] [Google Scholar]
  18. Kint B., Degreef H., Dooms-Goossens A. Combined allergy to human seminal plasma and latex: case report and review of the literature. Contact Dermatitis. 1994 Jan;30(1):7–11. doi: 10.1111/j.1600-0536.1994.tb00720.x. [DOI] [PubMed] [Google Scholar]
  19. Kowalski T. E., Falestiny M., Furth E., Malet P. F. Vitamin A hepatotoxicity: a cautionary note regarding 25,000 IU supplements. Am J Med. 1994 Dec;97(6):523–528. doi: 10.1016/0002-9343(94)90347-6. [DOI] [PubMed] [Google Scholar]
  20. Laupacis A., Sackett D. L., Roberts R. S. An assessment of clinically useful measures of the consequences of treatment. N Engl J Med. 1988 Jun 30;318(26):1728–1733. doi: 10.1056/NEJM198806303182605. [DOI] [PubMed] [Google Scholar]
  21. Leibovici A., Lavi N., Wainstok S., Herman J., Greene V. W. Low-dose acetylsalicylic acid use and hemoglobin levels. Effects in a primary care population. Can Fam Physician. 1995 Jan;41:64–68. [PMC free article] [PubMed] [Google Scholar]
  22. Lerman C., Trock B., Rimer B. K., Boyce A., Jepson C., Engstrom P. F. Psychological and behavioral implications of abnormal mammograms. Ann Intern Med. 1991 Apr 15;114(8):657–661. doi: 10.7326/0003-4819-114-8-657. [DOI] [PubMed] [Google Scholar]
  23. Liddell M. J. Mass mammographic screening--the other side of the argument. Aust Fam Physician. 1993 Jul;22(7):1168–1175. [PubMed] [Google Scholar]
  24. Mandel J. S., Bond J. H., Church T. R., Snover D. C., Bradley G. M., Schuman L. M., Ederer F. Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study. N Engl J Med. 1993 May 13;328(19):1365–1371. doi: 10.1056/NEJM199305133281901. [DOI] [PubMed] [Google Scholar]
  25. Marshall K. G. Screening for prostate cancer. How can patients give informed consent? Can Fam Physician. 1993 Nov;39:2385–2390. [PMC free article] [PubMed] [Google Scholar]
  26. Mayeaux E. J., Jr, Harper M. B., Abreo F., Pope J. B., Phillips G. S. A comparison of the reliability of repeat cervical smears and colposcopy in patients with abnormal cervical cytology. J Fam Pract. 1995 Jan;40(1):57–62. [PubMed] [Google Scholar]
  27. Miller A. B., Baines C. J., To T., Wall C. Canadian National Breast Screening Study: 2. Breast cancer detection and death rates among women aged 50 to 59 years. CMAJ. 1992 Nov 15;147(10):1477–1488. [PMC free article] [PubMed] [Google Scholar]
  28. Mittleman M. A., Maclure M., Tofler G. H., Sherwood J. B., Goldberg R. J., Muller J. E. Triggering of acute myocardial infarction by heavy physical exertion. Protection against triggering by regular exertion. Determinants of Myocardial Infarction Onset Study Investigators. N Engl J Med. 1993 Dec 2;329(23):1677–1683. doi: 10.1056/NEJM199312023292301. [DOI] [PubMed] [Google Scholar]
  29. Muldoon M. F., Manuck S. B., Matthews K. A. Lowering cholesterol concentrations and mortality: a quantitative review of primary prevention trials. BMJ. 1990 Aug 11;301(6747):309–314. doi: 10.1136/bmj.301.6747.309. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Naylor C. D., Chen E., Strauss B. Measured enthusiasm: does the method of reporting trial results alter perceptions of therapeutic effectiveness? Ann Intern Med. 1992 Dec 1;117(11):916–921. doi: 10.7326/0003-4819-117-11-916. [DOI] [PubMed] [Google Scholar]
  31. Pamuk E. R., Williamson D. F., Serdula M. K., Madans J., Byers T. E. Weight loss and subsequent death in a cohort of U.S. adults. Ann Intern Med. 1993 Oct 1;119(7 Pt 2):744–748. doi: 10.7326/0003-4819-119-7_part_2-199310011-00023. [DOI] [PubMed] [Google Scholar]
  32. Roberts M. M., Alexander F. E., Anderson T. J., Chetty U., Donnan P. T., Forrest P., Hepburn W., Huggins A., Kirkpatrick A. E., Lamb J. Edinburgh trial of screening for breast cancer: mortality at seven years. Lancet. 1990 Feb 3;335(8684):241–246. doi: 10.1016/0140-6736(90)90066-e. [DOI] [PubMed] [Google Scholar]
  33. Rose G. Sick individuals and sick populations. Int J Epidemiol. 1985 Mar;14(1):32–38. doi: 10.1093/ije/14.1.32. [DOI] [PubMed] [Google Scholar]
  34. Scardino P. T., Weaver R., Hudson M. A. Early detection of prostate cancer. Hum Pathol. 1992 Mar;23(3):211–222. doi: 10.1016/0046-8177(92)90102-9. [DOI] [PubMed] [Google Scholar]
  35. Shapiro S., Venet W., Strax P., Venet L., Roeser R. Ten- to fourteen-year effect of screening on breast cancer mortality. J Natl Cancer Inst. 1982 Aug;69(2):349–355. [PubMed] [Google Scholar]
  36. Shenot P., Rivas D. A., Kalman D. D., Staas W. E., Jr, Chancellor M. B. Latex allergy manifested in urological surgery and care of adult spinal cord injured patients. Arch Phys Med Rehabil. 1994 Nov;75(11):1263–1265. doi: 10.1016/0003-9993(94)90016-7. [DOI] [PubMed] [Google Scholar]
  37. Shepherd J., Cobbe S. M., Ford I., Isles C. G., Lorimer A. R., MacFarlane P. W., McKillop J. H., Packard C. J. Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia. West of Scotland Coronary Prevention Study Group. N Engl J Med. 1995 Nov 16;333(20):1301–1307. doi: 10.1056/NEJM199511163332001. [DOI] [PubMed] [Google Scholar]
  38. Silagy C. A., McNeil J. J., Donnan G. A., Tonkin A. M., Worsam B., Campion K. Adverse effects of low-dose aspirin in a healthy elderly population. Clin Pharmacol Ther. 1993 Jul;54(1):84–89. doi: 10.1038/clpt.1993.115. [DOI] [PubMed] [Google Scholar]
  39. Smith G. D., Egger M. Who benefits from medical interventions? BMJ. 1994 Jan 8;308(6921):72–74. doi: 10.1136/bmj.308.6921.72. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Sorenson J. R., Levy H. L., Mangione T. W., Sepe S. J. Parental response to repeat testing of infants with 'false-positive' results in a newborn screening program. Pediatrics. 1984 Feb;73(2):183–187. [PubMed] [Google Scholar]
  41. Tabár L., Fagerberg C. J., Gad A., Baldetorp L., Holmberg L. H., Gröntoft O., Ljungquist U., Lundström B., Månson J. C., Eklund G. Reduction in mortality from breast cancer after mass screening with mammography. Randomised trial from the Breast Cancer Screening Working Group of the Swedish National Board of Health and Welfare. Lancet. 1985 Apr 13;1(8433):829–832. doi: 10.1016/s0140-6736(85)92204-4. [DOI] [PubMed] [Google Scholar]
  42. Weil J., Colin-Jones D., Langman M., Lawson D., Logan R., Murphy M., Rawlins M., Vessey M., Wainwright P. Prophylactic aspirin and risk of peptic ulcer bleeding. BMJ. 1995 Apr 1;310(6983):827–830. doi: 10.1136/bmj.310.6983.827. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Willich S. N., Lewis M., Löwel H., Arntz H. R., Schubert F., Schröder R. Physical exertion as a trigger of acute myocardial infarction. Triggers and Mechanisms of Myocardial Infarction Study Group. N Engl J Med. 1993 Dec 2;329(23):1684–1690. doi: 10.1056/NEJM199312023292302. [DOI] [PubMed] [Google Scholar]
  44. Wilson G. T. Relation of dieting and voluntary weight loss to psychological functioning and binge eating. Ann Intern Med. 1993 Oct 1;119(7 Pt 2):727–730. doi: 10.7326/0003-4819-119-7_part_2-199310011-00020. [DOI] [PubMed] [Google Scholar]
  45. al-Mazrou A., Scheifele D. W., Soong T., Bjornson G. Comparison of adverse reactions to whole-virion and split-virion influenza vaccines in hospital personnel. CMAJ. 1991 Aug 1;145(3):213–218. [PMC free article] [PubMed] [Google Scholar]

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