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Post-Hoc Enthusiasm and Wariness (PHEW)

S

Sunnybrook Health Sciences Centre

Status

Not yet enrolling

Conditions

Health Behavior

Treatments

Other: Patient self-report

Study type

Interventional

Funder types

Other

Identifiers

Details and patient eligibility

About

The post-hoc fallacy (also termed the post-hoc-ergo-propter-hoc fallacy) has been recognized for centuries with endless relevance. The general concept in medical care is that patients who improve after a treatment are not necessary patients who improve because of a treatment. Modern medicine provides multiple opportunities to examine such pitfalls of judgment due to the prevailing uncertainty, incompleteness of our understanding pathogenic mechanisms, and natural tendency to connect treatments to outcomes. In this study, we will investigate whether judgments about vitamin supplementation might demonstrate the post-hoc fallacy.

Full description

We plan to conduct a brief survey of pharmacies portraying a patient in two slightly different versions. One version will portray the patient who feels better after starting a vitamin supplement whereas another version will portray the patient who feels unchanged after starting a vitamin supplement. The patients will be randomly assigned to participants and otherwise contain identical information. Judgments will be measured by eliciting participants recommendation about continuing the vitamin (Appendix_Script).

Enrollment

100 estimated patients

Sex

All

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

  • Community pharmacist

Exclusion criteria

  • Outside Ontario

Trial design

Primary purpose

Health Services Research

Allocation

Randomized

Interventional model

Parallel Assignment

Masking

Double Blind

100 participants in 2 patient groups

Success
Experimental group
Description:
Symptomatic improvement present
Treatment:
Other: Patient self-report
Failure
Experimental group
Description:
Symptomatic improvement absent
Treatment:
Other: Patient self-report

Trial contacts and locations

0

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Central trial contact

Donald A Redelmeier, MD, MSc

Data sourced from clinicaltrials.gov

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