The effect of question wording in questionnaire surveys on placebo use in clinical practice

To identify factors that contribute to the high variability of the rates of use of placebo interventions reported in questionnaire surveys, the author investigated the effect of the explicit use of the word "placebo" in questionnaire surveys on placebo use in clinical practice on the results obtained. 190 primary care physicians in Poland were divided randomly into two groups. The groups received a questionnaire in which either the word placebo or the term "nonspecific methods of treatment" was used. The respondents who were asked explicitly about the use of placebo interventions declared that they never used placebo interventions significantly more often than participants asked about the use of nonspecific treatment methods. Moreover, the former reported significantly rarer use of placebo interventions than the latter. The study demonstrates that differences in the wording of questions in questionnaire surveys on placebo use can create statistically significant differences in results.