Remotely provided open-label placebo reduces frequency of and impairment
by allergic symptoms
Abstract
Background: Placebos being prescribed with full honesty and
disclosure (i.e., open-label placebo = OLP) have been shown to reduce
symptom burden in a variety of conditions. With regard to allergic
rhinits, previous research provided inconclusive evidence for the
effects of OLP, possibly related to a separate focus on either symptom
severity or symptom frequency. Overcoming this limitation of previous
research, the present study aimed to examine the effects of OLP on both
the severity and frequency of allergic symptoms. Methods: In a
randomized-controlled trial, patients with allergic rhinits (
N=74) were randomized to OLP or treatment as usual (TAU). Due to
the COVID-19 pandemic, OLP was administered remotely in a virtual
clinical encounter. Participants took placebo tablets for 14 days. The
primary outcomes were the severity and frequency of allergic symptoms.
The secondary endpoint was allergy-related impairment. Results:
OLP did not significantly improve symptom severity over TAU, F(1,
71) = 3.280, p = .074, ɳ² p = .044, but did
reduce symptom frequency, F(1, 71) = 7.272, p = .009, ɳ²
p = .093, and allergy-related impairment more than TAU,
F(1, 71) = 6.445, p = .013, ɳ² p = .083,
reflecting medium to large effects. The use of other anti-allergic
medication did not influence the results. Conclusions: While
OLP was able to lower the frequency of allergic symptoms and
allergy-related impairment substantially, its effects on symptom
severity were weaker. The remote provision of OLP suggests that physical
contact between patients and providers might not be necessary for OLP to
work.