Questionnaire survey on use of placebo
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《英国医生杂志》
1 Herzog Hospital and Hadassah School of Medicine, Department of Psychiatry, POB 35300, Jerusalem 91351, Israel
Correspondence to: P Lichtenberg licht@cc.huji.ac.il
Abstract
How common is the use of placebos in clinical practice? From the dearth of discussion in the medical literature—almost all references to placebo from a Medline search refer to a research context—one might surmise that the clinical use of placebos is exceedingly rare. The deception involved in administering a placebo certainly raises ethical questions, and some institutions have banned its use. Yet informal discussions with colleagues, as well as first hand observation of clinical activity in various medical departments, suggest the practice still occurs. The only other report that we could locate of placebo use in a clinical context goes back a quarter of a century.1 The authors found that the placebo was rarely (about once a year per physician) and inappropriately used.
We reappraised how frequently and in what circumstances physicians and hospital nurses use placebos in a clinical setting, how they understand the mechanisms of actions, their views on ethics, and whether they find placebos useful.
Methods
Table 1 shows the composition of the group. We have summarised the data from the questionnaire under six headings.
Table 1 Demographic and professional data for respondents to questionnaire on use of placebos
Frequency—When we planned the study we assumed that the use of placebo was not widespread and would not exceed 10%. Among our 89 respondents, however, 53 (60%) admitted using a placebo (95% confidence interval 49% to 70%). The age and sex of respondent did not affect results. In total, 53% of doctors and 71% of nurses reported using a placebo. Among users, 33 (62%; 37% of the total sample) used a placebo as often as once a month or more. Differences between physicians and nurses in reported use and frequency of use of placebo did not attain significance.
Perceived therapeutic value—Of those who used a placebo, most (48 of 51 who answered the question, or 94%) found that it was either generally (17, or 33%) or occasionally (31, or 61%) effective.
Information given to patients—Of those using the placebo, 36 (68%) tell the patient that he or she is receiving a real medicine, and nine (17%) say nothing at all. The rest either identify the placebo as such (two, or 4%) or tell the patient that he or she is receiving a non-specific medicine (six, or 11%).
Circumstances of use—We found a wide range of applications for placebo (table 2). Placebos were given in the form of saline infusions or intramuscular injections; paracetamol or vitamin C tablets instead of the ordinarily prescribed medication; sugar or artificial sweetener pills; or prepared placebo tablets. The medical conditions for which the placebos were used included anxiety, pain (including abdominal), agitation, vertigo, sleep problems, asthma, contractions in labour, withdrawal from recreational drugs, and angina pectoris (when the blood pressure was too low to allow for vasodilators). The stated value as a diagnostic tool, referred to in table 2, was to distinguish organic from psychogenic or simulated arthralgia, seizure disorder, and abdominal or other pain.
Table 2 Circumstances in which placebo was administered. Figures are number (percentage of those who reported use) of respondents*
Ethical stance—Of 79 responses on ethics, only four (5%) thought that the use of placebos should be categorically prohibited. Most of the others considered placebo use conditional on certain circumstances, such as prior experience (26, or 33%), notifying patients of receipt of a placebo (23, or 29%), or evidence from research that the placebo was effective (19, or 24%).
Perceived mechanism of action—Respondents were permitted to propose more than one mechanism of action for placebos. Of 83 responses, most (62, or 75%) attributed the effect purely to psychological mechanisms. An additional nine (11%) respondents suggested a combination of psychological and biochemical effects.
Discussion
Goodwin JS, Goodwin JM, Vogel AV. Knowledge and use of placebos by house officers and nurses. Ann Intern Med 1979;91: 106-10.
De Deyn PP, d'Hooge R. Placebos in clinical practice and research. J Med Ethics 1996;22: 140-6.
Hill J. Placebos in clinical care: for whose pleasure? Lancet 2003;362: 254.
Hrobjartsson A, Gotzsche PC. Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment. N Engl J Med 2001;344: 1594-602.
Brown WA. Placebo as a treatment for depression. Neuropsychopharmacology 1994;10: 265-9.
Lione A. Ethics of placebo use in clinical care. Lancet 2003;362: 999.
Lichtenberg P, Heresco-Levy U, Nitzan U. The ethics of the placebo in clinical practice. J Med Ethics (in press).
Vase L, Riley JL, Price DD. A comparison of placebo effects in clinical analgesic trials versus studies of placebo analgesia. Pain 2002;99: 443-52.
Hyland ME. Using the placebo response in clinical practice. Clin Med 2003;3: 347-50.(Uriel Nitzan, medical stu)
Correspondence to: P Lichtenberg licht@cc.huji.ac.il
Abstract
How common is the use of placebos in clinical practice? From the dearth of discussion in the medical literature—almost all references to placebo from a Medline search refer to a research context—one might surmise that the clinical use of placebos is exceedingly rare. The deception involved in administering a placebo certainly raises ethical questions, and some institutions have banned its use. Yet informal discussions with colleagues, as well as first hand observation of clinical activity in various medical departments, suggest the practice still occurs. The only other report that we could locate of placebo use in a clinical context goes back a quarter of a century.1 The authors found that the placebo was rarely (about once a year per physician) and inappropriately used.
We reappraised how frequently and in what circumstances physicians and hospital nurses use placebos in a clinical setting, how they understand the mechanisms of actions, their views on ethics, and whether they find placebos useful.
Methods
Table 1 shows the composition of the group. We have summarised the data from the questionnaire under six headings.
Table 1 Demographic and professional data for respondents to questionnaire on use of placebos
Frequency—When we planned the study we assumed that the use of placebo was not widespread and would not exceed 10%. Among our 89 respondents, however, 53 (60%) admitted using a placebo (95% confidence interval 49% to 70%). The age and sex of respondent did not affect results. In total, 53% of doctors and 71% of nurses reported using a placebo. Among users, 33 (62%; 37% of the total sample) used a placebo as often as once a month or more. Differences between physicians and nurses in reported use and frequency of use of placebo did not attain significance.
Perceived therapeutic value—Of those who used a placebo, most (48 of 51 who answered the question, or 94%) found that it was either generally (17, or 33%) or occasionally (31, or 61%) effective.
Information given to patients—Of those using the placebo, 36 (68%) tell the patient that he or she is receiving a real medicine, and nine (17%) say nothing at all. The rest either identify the placebo as such (two, or 4%) or tell the patient that he or she is receiving a non-specific medicine (six, or 11%).
Circumstances of use—We found a wide range of applications for placebo (table 2). Placebos were given in the form of saline infusions or intramuscular injections; paracetamol or vitamin C tablets instead of the ordinarily prescribed medication; sugar or artificial sweetener pills; or prepared placebo tablets. The medical conditions for which the placebos were used included anxiety, pain (including abdominal), agitation, vertigo, sleep problems, asthma, contractions in labour, withdrawal from recreational drugs, and angina pectoris (when the blood pressure was too low to allow for vasodilators). The stated value as a diagnostic tool, referred to in table 2, was to distinguish organic from psychogenic or simulated arthralgia, seizure disorder, and abdominal or other pain.
Table 2 Circumstances in which placebo was administered. Figures are number (percentage of those who reported use) of respondents*
Ethical stance—Of 79 responses on ethics, only four (5%) thought that the use of placebos should be categorically prohibited. Most of the others considered placebo use conditional on certain circumstances, such as prior experience (26, or 33%), notifying patients of receipt of a placebo (23, or 29%), or evidence from research that the placebo was effective (19, or 24%).
Perceived mechanism of action—Respondents were permitted to propose more than one mechanism of action for placebos. Of 83 responses, most (62, or 75%) attributed the effect purely to psychological mechanisms. An additional nine (11%) respondents suggested a combination of psychological and biochemical effects.
Discussion
Goodwin JS, Goodwin JM, Vogel AV. Knowledge and use of placebos by house officers and nurses. Ann Intern Med 1979;91: 106-10.
De Deyn PP, d'Hooge R. Placebos in clinical practice and research. J Med Ethics 1996;22: 140-6.
Hill J. Placebos in clinical care: for whose pleasure? Lancet 2003;362: 254.
Hrobjartsson A, Gotzsche PC. Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment. N Engl J Med 2001;344: 1594-602.
Brown WA. Placebo as a treatment for depression. Neuropsychopharmacology 1994;10: 265-9.
Lione A. Ethics of placebo use in clinical care. Lancet 2003;362: 999.
Lichtenberg P, Heresco-Levy U, Nitzan U. The ethics of the placebo in clinical practice. J Med Ethics (in press).
Vase L, Riley JL, Price DD. A comparison of placebo effects in clinical analgesic trials versus studies of placebo analgesia. Pain 2002;99: 443-52.
Hyland ME. Using the placebo response in clinical practice. Clin Med 2003;3: 347-50.(Uriel Nitzan, medical stu)