NCT05686889

Brief Summary

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.

Trial Health

65
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
100

participants targeted

Target at P50-P75 for not_applicable

Timeline
28mo left

Started May 2023

Longer than P75 for not_applicable

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress57%
May 2023Sep 2028

First Submitted

Initial submission to the registry

January 7, 2023

Completed
10 days until next milestone

First Posted

Study publicly available on registry

January 17, 2023

Completed
3 months until next milestone

Study Start

First participant enrolled

May 1, 2023

Completed
4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

September 1, 2023

Completed
5 years until next milestone

Study Completion

Last participant's last visit for all outcomes

September 1, 2028

Expected
Last Updated

January 17, 2023

Status Verified

January 1, 2023

Enrollment Period

4 months

First QC Date

January 7, 2023

Last Update Submit

January 7, 2023

Conditions

Health Behavior

Outcome Measures

Primary Outcomes (1)

  • Response variable in each survey is a binary recommendation whether to continue the vitamin supplement or discontinue the vitamin supplement

    Health provider clinical recommendation

    Short-term (less than 5 minutes)

Study Arms (2)

Success

EXPERIMENTAL

Symptomatic improvement present

Other: Patient self-report

Failure

EXPERIMENTAL

Symptomatic improvement absent

Other: Patient self-report

Interventions

Patient self-reportOTHER

Simulated patient following structured script

FailureSuccess

Eligibility Criteria

Sexall
Healthy VolunteersYes
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

  • Community pharmacist

You may not qualify if:

  • Outside Ontario

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Health Behavior

Interventions

Self Report

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Surveys and QuestionnairesData CollectionEpidemiologic MethodsInvestigative TechniquesHealth Care Evaluation MechanismsQuality of Health CareHealth Care Quality, Access, and EvaluationPublic HealthEnvironment and Public Health

Study Officials

  • Donald A Redelmeier, MD, MSc

    Sunnybrook Health Sciences Centre

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Donald A Redelmeier, MD, MSc

CONTACT

4164806999dar@ices.on.ca

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, CARE PROVIDER
Purpose
HEALTH SERVICES RESEARCH
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Senior Scientist

Study Record Dates

First Submitted

January 7, 2023

First Posted

January 17, 2023

Study Start

May 1, 2023

Primary Completion

September 1, 2023

Study Completion (Estimated)

September 1, 2028

Last Updated

January 17, 2023

Record last verified: 2023-01

Data Sharing

IPD Sharing
Will not share