Background: Placebo interventions can have meaningful effects for patients. However, little is known about the circumstances of their use in clinical practice. We aimed to investigate to what extent and in which way Swiss primary care providers use placebo interventions. Furthermore we explored their ideas about the ethical and legal issues involved.
Methods: 599 questionnaires were sent to general practitioners (GPs) and paediatricians in private practice in the Canton of Zurich in Switzerland. To allow for subgroup analysis GPs in urban, suburban, and rural areas as well as paediatricians were selected in an even ratio.
Results: 233 questionnaires were completed (response rate 47%). 28% of participants reported that they never used placebo interventions. More participants used impure placebos therapeutically than pure placebos (57% versus 17%, McNemar's chi(2) = 78, p < 0.001). There is not one clear main reason for placebo prescription. Placebo use was communicated to patients mostly as being "a drug or a therapy" (64%). The most frequently chosen ethical premise was that they "can be used as long as the physician and the patient work together in partnership" (60% for pure and 75% for impure placebos, McNemar's chi(2) = 12, p < 0.001). A considerable number of participants (11-38%) were indecisive about statements regarding the ethical and legal legitimacy of using placebos.
Conclusion: The data obtained from Swiss primary care providers reflect a broad variety of views about placebo interventions as well as a widespread uncertainty regarding their legitimacy. Primary care providers seem to preferentially use impure as compared to pure placebos in their daily practice. An intense debate is required on appropriate standards regarding the clinical use of placebo interventions among medical professionals.