Introduction
allergic symptoms, Allergic rhinitis, OLP
ALLERGIC RHINITIS, BLIND, SEASONAL ALLERGIC RHINITIS
At least since the famous article about the “powerful placebo” by BeecherUnfortunately, deception of placebos is believed to be the crucial element of a placebo effect, resulting in severe ethical problems (e.g., undermining of consent and trust between patient and healthcare provider) when trying to administer placebos. Until very recently the idea to give placebos without deception would have been considered ridiculous, but intriguing new evidence demonstrates that open-label placebos (OLPs) may help patients with various clinical disordersHowever, most of those OLP studies represent only two-arm studies, usually the OLP and a treatment-as-usual (TAU) condition. This is problematic because of a possible different handling of the groups. Although the formal patient-experimenter interaction may be identical for both groups, the experimenter might unconsciously be more focused on participants of the OLP group and thereby providing more support to them. Given that OLP trials obviously cannot be blinded (participants know the hypothesis) and most studies report self-report data, response bias might be a consequence of these subliminal interactions. Blinded experimenters and additional control conditions such as conventional placebos would help to address this problem. This could also help to answer the question about the efficacy of an OLP treatment. Thus, reported effect sizes of OLP interventions are usually based on comparisons with TAU conditions, but it is not known whether the effect sizes of OLP are similar or lower or higher than conventional double-blind placebos. Both assumptions may be justified since the mechanisms of OLP might be different from conventional placebos. It is also important to assess the potential impact of OLPs because of possible practical implications.The present study intended to address this gap. We aimed to test the efficacy of an OLP approach relative to a double-blind placebo, and TAU. Thus, we conducted a randomized-controlled trial on the effects of OLPs on symptoms of seasonal allergic rhinitis.Allergic rhinitis affects up to 20% of the population in the developed world and is associated with a high economic burdenThe current study included 89 patients with seasonal allergic symptoms. In a 4 weeks trial we tested whether an OLP treatment is superior to TAU and compare its efficacy with a conventional double blind placebo condition. The results should help us to assess the impact of an OLP treatment.