Longitudinal Access to Physicians Study

Last registered on January 05, 2026
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Pre-Trial

Trial Information

General Information

Title
Longitudinal Access to Physicians Study
RCT ID
AEARCTR-0017536
Initial registration date
December 22, 2025

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
January 05, 2026, 7:09 AM EST

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

Locations

Country
United States of America
Region

Primary Investigator

Name
Rajiv Sharma
Affiliation
Portland State University
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Other Primary Investigator(s)

PI Name
Sarah Tinkler
PI Affiliation
Portland State University
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PI Name
Brigham Walker
PI Affiliation
Tulane University
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PI Name
Janna Wisniewski
PI Affiliation
Tulane University
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Additional Trial Information

Status
On going
Start date
2013-08-01
End date
2030-12-31
Keywords
Health
Additional Keywords
Access to primary care
JEL code(s)
I11
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The Longitudinal Access to Physicians Study (LAPS) is an ongoing audit of appointment availability with primary care physicians in the United States. Trained research assistants call a national random sample of primary care physicians on behalf of simulated patients asking about the availability of an appointment for a physical exam for a new patient. LAPS has collected data annually since its inception in 2013. The study is designed to permit assessments of the impacts of unanticipated (e.g., the onset of the COVID-19 pandemic) and anticipated (e.g., policy changes such as the expiration of enhanced tax credits for the ACA's exchange-purchased health insurance plans) shocks to the healthcare system on the availability of new patient appointments with primary care physicians.
External Link(s)

Registration Citation

Citation
Sharma, Rajiv et al. 2026. "Longitudinal Access to Physicians Study." AEA RCT Registry. January 05. https://doi.org/10.1257/rct.17536-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2013-08-01
Intervention End Date
2030-12-31

Primary Outcomes

Primary Outcomes (end points)
The primary outcomes are (1) whether a patient is offered an appointment by the physicians' office and (2) the wait time (number of days) to the appointment if an appointment is offered.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
A simulated patient profile is randomly assigned each physician in a national random sample of primary care physicians. Trained research assistants call physicians' offices to request appointment availability information on behalf of the simulated patient. Simulated patient profiles differ by race/ethnicity, gender, and insurance type. Race/ethnicity are signaled using names that are racially/ethnically distinct.
Experimental Design Details
Not available
Randomization Method
Computer will assign each physician one of 72 patient patient profiles.
Randomization Unit
Physician.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Treatment is not clustered.
Sample size: planned number of observations
Between 800 and 4,000 reachable and eligible physicians annually.
Sample size (or number of clusters) by treatment arms
Simulated patients in the study differ by race/ethnicity (Black, Hispanic, White), gender (women, men), and insurance type (Medicare, Medicaid, private insurance, self-pay or uninsured). We aim to collect 40 or more observations per year for each group yielding an annual sample size of 960 or more.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Institutional Review Board, Portland State University
IRB Approval Date
2013-07-29
IRB Approval Number
196582-18
Analysis Plan