Attached
Objective: Clinically irrelevant but psychologically important
factors such as patients’ expectations for antibiotics
encourage overprescribing. We aimecf'to (a) provide missing
causal evidence of this effect, (b) identify whether the
expectations distort the perceived probability of a bacterial
infection either in a pre- or postdecisiohai distortions pathway, and (o'; detect possible moderators of this effect.
Method: Family physicians expressed their willingness to
prescribe antibiotics (Experiment 1, m = 305) or their
decision to prescribe (Experiment 2, n2 = 131) and assessed
the probability of a bacterial infection in hypothetical patients
with infections either with low or high expectations for
antibiotics. Response order of prescribing/probability was
manipulated in Experiment 1. Results: Overall, the
expectations for antibiotics increased intention to prescribe
(Experiment 1, F(1: 301) = 25.32, p< .001, r\ p2 = .08,
regardless of the response order; Experiment 2, odds ratio
[OR] = 2.31, and OR = 0.75, Vignettes 1 and 2, respectively).
Expectations for antibiotics did not change the perceived
probability of a bacterial infection (Experiment 1, F(1, 301) =
1.86, p = .173, np2 = .01, regardless of the response order;
Experiment 2, d = -0.03, and d = +0.25, Vignettes 1 and 2,
respectively). Physicians’ experience was positively
associated with prescribing, but it did not moderate the
expectations effect on prescribing. Conclusions: Patients’
and their parents’ expectations increase-antibiotics
prescribing, but their effect is localized— it does not leak into
the perceived probability of a bacterial infection.
Interventions reducing the overprescribing of antibiotics
should target also psychological factors
