Table 2 Summary of findings on the frequency of placebo use.
Author year | Setting | Type | Placebo use | Definition of use | Frequency or other additional information |
|---|---|---|---|---|---|
Questionnaire- based quantitative surveys | Â | Â | Â | Â | Â |
Physicians | Â | Â | Â | Â | Â |
Goodwin 1979 [19] | Hospital (house officers) | Pure* | 78% | Ever use for pain relief | Â |
Gray 1981 [20] | Hospital | Pure | 80% | Ever use | Â |
Classen 1985 [23] | Unclear | Pure | 60% | Use 'sometimes' | About 30% less than once a month |
Classen 1985 [23] | Unclear | Impure | 54% | Use 'sometimes' | Â |
Lynöe 1993 [26] | Unclear | Both | 99% | Ever use | None very often, 1% often, 4% rather often, 26% quite rarely, 68% rarely/very rarely |
Hrobjartsson 2003 [30] | General practice | Both | 86% | During the last year | 38% 1-10 times/year, 48% > 10 times/year |
Hrobjartsson 2003 [30] | Hospital | Both | 54% | During the last year | 44% 1-10 times/year, 10% > 10 times/year |
Hrobjartsson 2003 [30] | Specialist practice | Both | 41% | During the last year | 31% 1-10 times/year, 10% > 10 times/year |
Nitzan 2004 [31] | Hospital/family practice | Pure* | 53% | Use with a minimum frequency of once a year | 37% once a month or more often†|
Sherman 2007 [33] | Medical school faculty | Both | 45% | Ever use | 15% 1-10Ă—, 8% > 10Ă—, 22% not at all during last year |
Tilburt 2008 [34] | Specialist practice | Both | 80% | Ever use | 34% = once a month, 28% 2-3 times/month, 18% = once a week |
Bernateck 2009 [35] | Hospital | Pure | 52% | Use with a minimum frequency of once a year | 40% 1-2 times/year, 9% 1-2 times/month, 4% more often |
Fässler 2009 [37] | Primary care | Pure | 17% | Ever use | 93% once a month or less often |
Fässler 2009 [37] | Primary care | Impure | 57% | Ever use |  |
Nurses | Â | Â | Â | Â | Â |
Goldberg 1979 [18] | Hospital | Pure | 51% | Ever use | 44% with current use or use in the last 6 months |
Goodwin 1979 [19] | Hospital | Pure* | 82% | Ever use for pain relief | Â |
Gray 1981 (sample 1) [20] | Hospital | Pure | 80% | Ever use | Â |
Gray 1981 (sample 2) [20] | Hospital | Pure | 89% | At least once during the last 5 years | 63% during the last year |
Saupe 1985 [24] | Hospital | Pure | 100% | Ever use | 79% once or less per month, 21% more often |
Ernst 1997 [27] | Unclear | Pure | 57% | Ever use | Â |
Ernst 1997 [27] | Unclear | Both | 68% | Ever use | 12% during the last year |
Nitzan 2004 [31] | Hospital | Pure* | 71% | Use with a minimum frequency of once a year | 37% once a month or more often†|
Bernateck 2009 [35] | Hospital | Pure | 87% | Use with a minimum frequency of once a year | 45% 1-2 times/year, 33% 1-2 times/month, 9% more often |
Interns | Â | Â | Â | Â | Â |
Berger 1999 [28] | Hospital | Pure | 16% | Ever witnessed use | Only 2% (1/47) had actually given a placebo |
Substudies with prospective screening of medical records of hospital patients | Â | Â | Â | Â | Â |
Goodwin 1979 [19] | Hospital | Pure* | 0.3% | During 6 months (prospective) | Â |
Lange 1981 [21] | Psychiatric hospital | Pure | 5.1% | During 12 months (prospective) | 6.1% in women, 3.9% in men |