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

Physicians

Goodwin 1979 [19]

Hospital (house officers)

Pure*

78%

Ever use for pain relief

Gray 1981 [20]

Hospital

Pure

80%

Ever use

Classen 1985 [23]

Unclear

Pure

60%

Use 'sometimes'

About 30% less than once a month

Classen 1985 [23]

Unclear

Impure

54%

Use 'sometimes'

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% 1-10×, 8% > 10×, 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

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

Gray 1981 (sample 1) [20]

Hospital

Pure

80%

Ever use

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

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

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

Goodwin 1979 [19]

Hospital

Pure*

0.3%

During 6 months (prospective)

Lange 1981 [21]

Psychiatric hospital

Pure

5.1%

During 12 months (prospective)

6.1% in women, 3.9% in men

* Limitation to pure placebo not explicitly stated but questions/report with clear focus on pure placebo use.

† Numbers related to both physicians and nurses.

Fässler et al. BMC Medicine 2010 8:15   doi:10.1186/1741-7015-8-15