THE MEDICAL EXPERTISE BIAS. HOW TO BECOME THE EPISTEMIC AUTHORITY FOR YOUR PATIENTS? Katarzyna Stasiuk1, Yoram Bar Tal2, Renata Maksymiuk1 1 Maria Curie Sklodowska University, Poland 2 Tel – Aviv University, Israel

Adherence to prevention and disease management activities is poor across many disease conditions a substantial number of patients do not obtain the maximum benefit of medical treatment (Heerdink, et al., 2007). Physician-patient relationship is considered to be one of the most important factors that influence adherence (for a review, see DiMatteo, 2004). A physician's epistemic authority (EA) is a factor that is strongly connected to the physician-patient relationship and therefore affects patients’ adherence to medical recommendations.

What is the epistemic authority? Epistemic authority (EA) - the part of lay epistemic theory concerning the process of the knowledge formation (Kruglanski, 1989) EA is the source of information which can strongly influence knowledge formation. Individuals process information from high EA as if the information is more definite and certain, and tend to act in accordance with its implications (Kruglanski, 1995).

Who is the epistemic authority? The concept of EA is equivalent to objective expertise; however EA focus on subjective beliefs concerning its source. Lay people may use different parameters to evaluate the degree to which the source of information is valuable as a basis for making own decisions (= is EA) – e.g. professional role, level of education, but also … specific actions or opinions that are giving by the source of information (e.g. physician).

Physician’s epistemic authority Perceiving physicians as having a high EA may reduce patients’ uncertainty and increase their belief in a physician’s ability to help (Madar & Bar–Tal, 2009). As a result, patients may be more willing to follow a physician’s recommendations without testing those recommendations or considering any other alternatives (Kruglanski, Orehek, Dechesne & Pierro, 2010).

WHAT INFLUENCES THE PHYSICIAN’S EA? THE ROLE OF RECOMMENDATION

Active recommendation One of the factors that influence the perception of physician's EA may be the type of recommendation to the patient Active recommendation Passive recommendation PHYSICIAN EA Bar-Tal Y., Stasiuk K., Maksymiuk R. A. (2013). Patients’ perceptions of physicians’ epistemic authority when recommending flu inoculation. Health Psychology, 32(6), 706-709. Barnoy, S., Levy, O., & Bar-Tal, Y. (2010) Nurse or physician: whose recommendation influences the decision to take genetic tests more? Journal of Advanced Nursing, 66(4), 806-813.

The present study Does the connection between a physician’s recommendation and EA reflects the element of activity (a more active recommendation is perceived as reflecting a higher EA) or does the size of the recommendation determine the EA (the more serious the treatment the higher EA)? Passive recommendation – „don’t” vs „wait” What is the mechanism of this phenomena? Stasiuk, K., Bar – Tal, Y., Maksymiuk, R. (in press). The Effect of Physicians’ Treatment Recommendations on Their Epistemic Authority: the Medical Expertise Bias. Journal of Health Communication

Participants and design 631 participants (302 M, 329 W) age 24 – 54 (M= 32.22, SD = 7.42) BETWEEN PARTICIPANTS FACTORIAL DESIGN 3 physician specialty conditions (surgeon, orthopaedist, dentist). dental caries, sciatica, varicose veins 2 physician expertise conditions (low expertise/high expertise)

5 recommendation conditions 1) against , 2) wait, 3) minor recommendation (antibacterial and analgesic medicines for dental caries, anti–inflammatory medicine for sciatica, compression stockings for varicose veins), 4) moderate recommendation (endodontic procedure for dental caries, intensive physiotherapy for sciatica, sclerotherapy for varicose veins), 5) major recommendation (tooth extraction for dental caries, neurosurgery treatment for sciatica, varicose vein surgery). DEPENDENT VARIABLES Perception of physician’s EA (is PH an expert in the domain, do you trust the PH, do other physicians advise the same..) Perception of physician efforts to help the patient (did PH try to help the patient, did PH cares about the patients, would your friend would be satisfied with the visit)

Results - the recommendation’s effect Physician’s EA Passive recommendations Physician carering abot patient Active recommendations Passive recommendations F (4, 601) = 17,73, ἠ = 0,11 F (4, 601) = 23,82, ἠ = 0,13

Results - the mechanism of recommendation’s effect Caring about the patient Recommendation Physician epistemic authority 0,96*** 0,63*** 0,62*** (0,05) R2 = 74% Mediation effect = 0,61; boot se = 0,07 95% boot CI [0,49;0,76]

Results – recommendation x physician’s specialty Physician EA F (2, 601) = 5,55, ἠ = 0,07 When surgeon advises against treatment it doesn’t decreases their EA Seriousness of ilness fear of surgical procedures, fear of neccesity to stay in hospital, fear of surgical procedures’ consequences higher uncertainty

Is the effect of active recommendation or just the effect of confirmation bias?

Study 2 physician recommendation and patient’s attitude Participants: 187 participants (111 women, 76 men). Procedure: the participants were asked to imagine the situation, when they visiting the physician, who recommends (or not) the flu inoculation. Independent variables: physician’s recommendation (to inoculate or not to inoculate), attitude towards the flu inoculation (neg. vs neutr. vs pos.). Dependent variable: estimation of physician’s epistemic authority.

Results The estimation of AE regarding the recommendation and the patient attitude towards the inoculation F(2,177)=4.11, p<.05, ή2=0.04).

When the attitude towards the inoculation is positive and the physician recommends it, the estimation of his AE increases. When the physician advises against the inoculation contrary to the patient's attitude, his EA decreases. However, when the patient's attitude towards the inoculation is negative, the doctor's recommendation doesn't influence the estimation of his EA (so it is not the confirmation bias effect).

Conclusions The doctor who recommends action is perceived as a higher AE, than the one who doesn't recommend against it. It seems that the patients expect from their physician the active treatment, and the recommendation connected rather with action, then passivity. “Medical expertise bias" - people might be biased when judging the level of expertise of their physicians. Making a more active recommendation may be a prerequisite for being considered a high epistemic authority, and can serve as a kind of a universal heuristic (authority – action).