Quality signals in health care: a vignette experiment in South Africa

Last registered on December 30, 2021
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Pre-Trial

Trial Information

General Information

Title
Quality signals in health care: a vignette experiment in South Africa
RCT ID
AEARCTR-0008443
Initial registration date
October 25, 2021

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
October 27, 2021, 10:38 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
December 30, 2021, 12:41 PM EST

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Country
South Africa
Region

Primary Investigator

Name
Nicholas Stacey
Affiliation
LSE
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Other Primary Investigator(s)

PI Name
Mylene Lagarde
PI Affiliation
LSE
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PI Name
Duane Blaauw
PI Affiliation
University of the Witwatersrand
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Additional Trial Information

Status
In development
Start date
2021-10-26
End date
2022-02-28
Keywords
Health
Additional Keywords
Healthcare, quality, South Africa
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Overtreatment is widespread in health care, including in low- and middle-income settings. In primary care, providers often recommend unnecessary drugs, with potential dire consequences for patients, health systems and public health. Recent evidence suggests that providers recommend unnecessary treatment even in the absence of direct financial incentives and when they know what the appropriate treatment is. Providers have sometimes explained their decisions to overtreat as a response to an actual or perceived demand from patients, who, in a relationship characterized by asymmetry of information, may interpret treatment characteristics as a signal of quality. We design a simple vignette experiment to test (1) whether reduced overtreatment is perceived as a signal of worse quality of care and (2) the relevance of the treatment signal against another typical signal of quality care (thoroughness of the consultation).
External Link(s)

Registration Citation

Citation
Blaauw, Duane, Mylene Lagarde and Nicholas Stacey. 2021. "Quality signals in health care: a vignette experiment in South Africa." AEA RCT Registry. December 30. https://doi.org/10.1257/rct.8443-1.2000000000000002
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
In a survey experiment respondents see and rate one clinical vignette depicting the story of a patient suffering from a minor lower-respiratory tract infection (acute bronchitis) who decides to consult a doctor. Our design cross-randomizes variation in the type of treatment recommended by the doctor with information about the thoroughness of the consultation, in a 5x2 design. Along the treatment dimension, each respondent sees one of five possible treatment outcomes:
- No drugs prescribed
- Two Over-the-Counter (OTC) drugs prescribed
- Four OTC drugs prescribed
- Two drugs prescribed: one prescription drug (antibiotic) and one OTC drug.
- Four drugs prescribed: two prescription drugs (antibiotic and steroids) and two OTC drugs.

Along the second dimension, we randomize the amount of information about the technical quality of the consultation process. For respondents assigned to receiving some information about the consultation, the vignette includes a summary of the questions asked by the providers and physical examinations undertaken.
Intervention Start Date
2021-10-26
Intervention End Date
2022-02-28

Primary Outcomes

Primary Outcomes (end points)
The main outcomes of interest are the first-order beliefs of respondent, judging different aspects of quality of care. The main outcome is a rating of the provider’s competence on a scale of 1-4.
Other outcomes of interest include rating of the effectiveness of care received, the treatment safety, and satisfaction with the provider (likelihood to us the same doctor again).
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary outcomes include second-order beliefs of the same four dimensions quality of care, which are incentivised.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This survey experiment is embedded in a broader survey looking at provider preferences and the demand for healthcare. Survey respondents are part of an online panel in South Africa, aged 18-65, who do not have a medical health insurance. Respondents see and rate one clinical vignette depicting the story of a patient suffering from a minor lower-respiratory tract infection (acute bronchitis) who decides to consult a doctor. The design cross-randomizes variation in the type of treatment recommended by the doctor with information about the thoroughness of the consultation, in a 5x2 design. Along the treatment dimension, each respondent sees one of five possible treatment outcomes:
- No drugs prescribed
- Two Over-the-Counter (OTC) drugs prescribed
- Four OTC drugs prescribed
- Two drugs prescribed: one prescription drug (antibiotic) and one OTC drug.
- Four drugs prescribed: two prescription drugs (antibiotic and steroids) and two OTC drugs.
Along the second dimension, we randomize the amount of information about the technical quality of the consultation process. For respondents assigned to receiving some information about the consultation, the vignette includes a summary of the questions asked by the providers and physical examinations undertaken.
Experimental Design Details
Randomization Method
Survey platform random number generator.
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
1800
Sample size: planned number of observations
1800
Sample size (or number of clusters) by treatment arms
180 individuals per clinical vignette presentation.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The design is powered to detect a 0.3 standard deviation effect.
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
University of the Witwatersrand Human Research Ethics Committee (Non-medical)
IRB Approval Date
2021-09-15
IRB Approval Number
H21/07/49
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials