Table 1

Overview of included studies.

First author year

from

N

Participants

Sampling

Response rate

Focus pure/impure placebo


Questionnaire-based quantitative surveys

Shapiro 1973 [15,16]

USA

195

Ph (various groups)

Convenience

83%

Both

Goldberg 1979 [18]

USA

102

N (head nurses at 11 hospitals)

Local

68%

Pure

Goodwin 1979 [19]

USA

60

Ph (house officers)

Convenience

100%

Mainly

39

N (hospital nurses)

Convenience

Unclear

pure

27

License practical nurses/medical aides

Convenience

Unclear

Gray 1981 [20]

CAN

70

Ph (university hospital)

Convenience

82%*

Pure

230

N (university hospital)

Convenience

35

N (experienced hospital nurses)

Convenience

Unclear

Lange 1981 [21]

GER

81

Ph, N, psychologists (no data for subgroups provided)

Convenience

Unclear

Pure

Thomson 1982 [22]

NZ

37

Ph (GPs)

Local

84%

Both

Classen 1985 [23]

GER

101

Ph (setting unclear)

Convenience

Unclear

Both

Saupe 1986 [24]

GER

56

N (at a psychiatric university hospital)

Convenience

80%

Mainly pure

Lynöe 1993 [26]

SWE

94

Ph (GPs or affiliated with university)

Local

94%

Mainly

83

Pt (consecutive patients of three GPs)

Local

83%

impure

Ernst 1997 [27]

AUS

263

N (setting unclear)

Convenience

58%

Both

Berger 1999 [28]

USA

74

Medical interns at an university-affiliated hospital

Convenience

83%

Pure

Berthelot 2001 [29]

FRA

300

Pt (at a hospital rheumatology department)

Convenience

Unclear

Mainly

100

N (same hospital, various departments)

Convenience

Unclear

pure

Hrobjartsson 2003 [30]

DEN

502

Ph (GPs, hospital, specialists in private practice)

Random

65%

Both

Nitzan 2005 [31]

ISR

31

Ph (senior hospital physicians)

Convenience

76%

Mainly

31

N (head nurses from same hospitals)

Convenience

100%

pure

27

Ph (family physicians)

Convenience

68%

Lim 2007 [32]

SIN

402

Medical students

Local

36%

Pure

Sherman 2007 [33]

USA

231

Ph (faculty members of 3 medical schools)

Local

50%

Both

Tilburt 2008 [34]

USA

679

Ph (internists and rheumatologists)

Random

57%

Both

Bernateck 2009 [35]

GER

71

Ph (university hospital)

Convenience

80%*

Pure

107

N (university hospital)

Convenience

Chen 2009 [36]

NZ

211

Pt (in waiting rooms of two GP clinics)

Convenience

48%

Mainly pure

Fässler 2009 [37]

SWI

233

Ph (primary care)

Random

48%

Both

Substudies with prospective screening of medical records of hospital patients

Goodwin 1979 [19]

USA

1900

Pt (academic teaching hospital, treated during 6 months)

n.a.

Pure

Lange 1981 [21]

GER

1725

Pt (psychiatric hospital, all treated 1978)

n.a.

Pure

Qualitative studies

Comaroff 1976 [17]

UK

47

Ph (GPs)

Local

92%

Mainly impure

Schwartz 1989 [25]

USA

72

Ph (selected for often prescribing inefficient drugs)

n.a.

51%

Impure


*Response rate only reported for pooled groups.

Ph = physicians; N = nurses; Pt = patients; GPs = general practitioners; n.a. = not applicable.

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

Open Data