Changes in Medical and Cost Uncertainty and the Health Seeking Decision: Vignette Experiment in Pakistan

Last registered on November 30, 2023


Trial Information

General Information

Changes in Medical and Cost Uncertainty and the Health Seeking Decision: Vignette Experiment in Pakistan
Initial registration date
October 19, 2023

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
November 01, 2023, 2:32 PM EDT

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

Last updated
November 30, 2023, 6:05 AM EST

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


Primary Investigator

FAU Erlangen-Nürnberg

Other Primary Investigator(s)

PI Affiliation
FAU Erlangen-Nürnberg
PI Affiliation
FAU Erlangen-Nürnberg

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Health care decisions are sometimes a matter of life and death, but also their financial consequences can be disastrous for many households around the world. While one can imagine how the fear of making an expensive mistake may deter households from making otherwise sensible health care choices, there is almost no scientific evidence on the importance and joint role of medical and financial uncertainty. In this project, we first provide theoretical insights based on simulation exercises and develop a novel measurement instrument for medical and cost uncertainty using hypothetical health scenarios (vignettes). Initial analyses from data collected using this instrument with low-income households in Pakistan reveal that on top of many biases, both medical as well as cost uncertainty in health care decisions exist and may deter sensible health investments, in line with the theoretical predictions. As these results indicate potentially large dividends to providing accurate information, we are now conducting an extended vignette survey that includes three within-survey information interventions targeted at changing medical or cost uncertainty separately or jointly. With this RCT, we aim to test in two intervention stages whether: i) the interventions reduce biases and uncertainties; ii) the interventions change the hypothetical health seeking decision; and iii) the joint intervention induces larger changes.
External Link(s)

Registration Citation

Imping, Alina, Andreas Landmann and Lisa Rogge. 2023. "Changes in Medical and Cost Uncertainty and the Health Seeking Decision: Vignette Experiment in Pakistan." AEA RCT Registry. November 30.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Hypothetical healthcare decision (whether and where to seek care, ranking) before and after overview
Scenario- and facility-specific expected probability to get better, cost, medical and cost uncertainty
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment will be fielded within a household survey with low-income households in four districts in Khyber Pakhtunkhwa, Pakistan. It is part of a game-like survey tool that asks respondents to imagine being exposed to a health shock that is defined by a health vignette script, assess medical and cost uncertainties for six care-seeking options and finally take a hypothetical decision for one of these six options. Each respondent is presented with two health scenarios subsequently: one light scenario that does not require formal medical care (light fever) and one severe scenario (randomly selected from heart disease and appendicitis).
Within each scenario, there are two stages of interventions: first, respondents are randomly allocated to one of four equally sized groups: one control group that does not receive any additional information, and three treatment groups that receive additional information within the vignette: a) targeted at medical uncertainty (nature of health shock, recommended treatment and level of care); b) targeted at cost uncertainty (health insurance coverage); and c) information content of a) and b) combined. This information content is designed in a way that could also be communicated via a medical helpline. After presenting the vignette and information, facility-specific expected probability to get better, expected costs, medical and cost uncertainty are elicited followed by the first hypothetical healthcare decision. In the second intervention stage, all respondents are presented with an overview of their reported facility-specific expectations. Then, within treatment groups a)-c), half of the respondents will see an overview of all their answers like the control group, and the other (randomly selected) half will see the overview without medical uncertainty (a), cost uncertainty at secondary facilities (b) or both (c).
We will conduct a results-blind analysis before receiving the full data including treatment allocation.
Experimental Design Details
Randomization Method
Randomization on tablet within survey form at the time of the interview
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
4,000 households with one respondent each
Sample size: planned number of observations
4,000 households with one respondent each
Sample size (or number of clusters) by treatment arms
Control group: 1,000 respondents
Medical information treatment stage 1: 1,000 respondents; stage 2: 500 control overview and 500 overview without medical uncertainty
Cost information treatment stage 1: 1,000 respondents; stage 2: 500 control overview and 500 overview without cost uncertainty
Medical and cost information treatment stage 1: 1,000 respondents; stage 2: 500 control overview and 500 overview without medical and cost uncertainty
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ethics Commission of the School of Business, Economics and Society FAU Erlangen-Nürnberg
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials