Openly prescribed placebos to reduce symptoms of allergic rhinitis

INTERVENTION: Participants received either open‐label placebo plus treatment as usual (TAU) or TAU alone for their allergic rhinitis over the course of two weeks TAU+OLP If participants were randomized to TAU+OLP, participants were sent the placebo pills via postal service. The placebos were in a small glass container, which was sent to the participants in a padded envelope. Participants were asked to swallow the placebos, not to chew or suck them, twice a day (one tablet in the morning and another one in the evening). Participants took the placebos for 14 days. In addition to OLP, participants were allowed to continue to take their regular medication (if there was any), but were asked not to change their medication until the second study visit. TAU only Participants from the TAU group did not receive placebos after the first virtual study visit. With respect to their regular treatment, they received the same information as participants from the OLP group. Participants from the TAU group were offered the possibility of receiving the placebos after the second (virtual) study visit (“switch‐over"). Randomization and Blinding Prior to the first virtual appointment, participants were randomly allocated to one of the two clinical encounter styles (augmented vs. limited) using a computer‐generated randomization sequence. At the end of the first virtual encounter, the provider randomized participants to either OLP or the control group by opening a concealed container (visible to the participants). Thus, neither the provider nor the participant was blinded with respect to the participants’ treatment allocation. Participants were not aware, however, of their allocation in terms CONDITION: Allergic rhinitis ; Respiratory PRIMARY OUTCOME: Allergic symptoms measured using the combined symptom medication score (CSMS) at baseline and two weeks SECONDARY OUTCOME: Impairment caused by allergic symptoms measured using the adapted version of the Pain Disability Index (PDI) at baseline and two weeks INCLUSION CRITERIA: 1. Diagnosed allergic rhinitis 2. At least 18 years old 3. Sufficient German language skills