Factors that influence practitioners' interpretations of evidence from alternative medicine trials: a factorial vignette experiment embedded in a national survey.
BACKGROUND
Clinical trial evidence in controversial areas such as complementary and alternative medicine (CAM) must be approached with an open mind.


OBJECTIVE
To determine what factors may influence practitioners' interpretation of evidence from CAM trials.


METHODS
In a mailed survey of 2400 US CAM and conventional medicine practitioners we included 2 hypothetical factorial vignettes of positive and negative research results for CAM clinical trials. Vignettes contained randomly varied journal (Annals of Internal Medicine vs. Journal of Complementary and Alternative Medicine) and CAM treatment type (acupuncture, massage, glucosamine, meditation, and reiki). Response items also included randomly varied patient circumstances-chronic refractory symptoms and the patient requesting CAM.


METHODS
All practitioners rated the effectiveness and their willingness to recommend the therapy for a described patient. We used logistic regression to determine the independent influence of the 4 factors on respondents' effectiveness and legitimacy judgments.


RESULTS
A total of 1561 practitioners responded (65%). Relative to Reiki, conventional medicine practitioners were most willing to recommend glucosamine (OR = 3.0; 95% CI [1.6-5.4]), than massage (1.9 [1.1-3.3]), acupuncture (1.3 [0.8-2.2]), and meditation (1.2 [0.7-2.0]). CAM practitioners rated acupuncture as effective more than other CAM therapies (OR = 5.8 [2.6-12.8] compared with Reiki), and were more willing to recommend acupuncture (OR = 12.3 [4.8-31.8]). When presented evidence of inefficacy, CAM practitioners were most willing to recommend acupuncture relative to other CAM therapies (OR = 15.5 [9.0-26.9]).


CONCLUSIONS
Practitioners' judgments about CAM trial evidence depend on the type of treatments reported. Confirmation bias may play a role in the clinical translation of new evidence from clinical trials.
Tilburt
Jon C
JC
Department of Bioethics, National Institutes of Health, Bethesda, MD 20892, USA. tilburt.jon@mayo.edu
Miller
Franklin G
FG
Jenkins
Sarah
S
Kaptchuk
Ted J
TJ
Clarridge
Brian
B
Bolcic-Jankovic
Dragana
D
Emanuel
Ezekiel J
EJ
Curlin
Farr A
FA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000739:Anecdotes as Topic; D001291:Attitude of Health Personnel; D002908:Chronic Disease / Q000628:therapy; D002986:Clinical Trials as Topic; D000529:Complementary Therapies / Q000706:statistics & numerical data*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007600:Judgment; D008297:Male; D008875:Middle Aged; D057240:Patient Preference; D010820:Physicians / Q000523:psychology*; D011795:Surveys and Questionnaires