Designing effective interventions to increase the uptake of the HPV vaccine among adolescent girls (9-14 years)

Last registered on February 18, 2021


Trial Information

General Information

Designing effective interventions to increase the uptake of the HPV vaccine among adolescent girls (9-14 years)
Initial registration date
January 27, 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
January 27, 2021, 5:11 PM EST

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

Last updated
February 18, 2021, 3:59 AM EST

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



Primary Investigator


Other Primary Investigator(s)

PI Affiliation

Additional Trial Information

Start date
End date
Secondary IDs
In this study we evaluate communication-based interventions to decrease doctors’ hesitancy in prescribing the HPV vaccine to adolescent girls. In a field survey experiment, we expose medical practitioners -- general physicians, pediatricians and gynaecologists -- to a video based stimulus and collect information on attitudes, intentions, before and after the intervention. We test for 5 different interventions -- endorsement from trusted medical experts, providing conversational tips, combining HPV vaccine prescription with other widely accepted medical prescriptions, poster-based nudges, and increasing salience of risk from HPV. We conduct our survey experiment with a sample of medical practitioners in West Bengal using self-administered computer assisted personal interviews.
External Link(s)

Registration Citation

Mamidi, Pavan, Diksha Radhakrishnan and Shardul Vaidya. 2021. "Designing effective interventions to increase the uptake of the HPV vaccine among adolescent girls (9-14 years)." AEA RCT Registry. February 18.
Experimental Details


We test the following five interventions:
Physician champion: Having a trusted expert endorse the HPV vaccine.
Communications toolkit: Providing physicians with a toolkit containing both strategies and tips that can help navigate conversations on the HPV vaccine with parents of adolescent girls.
Bundling: Combining conversations on the HPV vaccine with other widely adopted health behaviours (for e.g. the Td/Tdap vaccine, cervical cancer screening, or other adolescent health topics such as reducing obesity).
Third party nudging: Placing the onus of having conversations about the vaccine on a neutral party, such as a group of doctors or medical associations endorsing the vaccine.
Salience: Increasing the salience of the incidence & risks of cervical cancer, and the efficacy of the HPV vaccine.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Our primary outcome variable is the intention to prescribe the HPV vaccine, to be answered on a 7-point likert scale.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Our research design is a simple experiment, where participants are exposed to a 2-3 minute video stimulus, bookended by a baseline and an endline measurement of outcome and control variables. We have 7 experimental arms in the study, one control arm and 6 treatment arms. Participants in the control arm are exposed to a video about Biodiversity -- which we hypothesise will have no impact on existing attitudes or intentions towards vaccine recommendations by participants. Participants in the treatment arms are exposed to a video based on the respective behavioural interventions, described in the previous section.
Each stimulus also has a supplementary image that is accessible to participants when they are answering the endline questionnaire.
Experimental Design Details
Randomization Method
Randomization is performed by Qualtrics.
Randomization Unit
Randomization is performed on the individual level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
NA, since there is no clustering in our design.
Sample size: planned number of observations
We intend to collect responses from 630 doctors in total.
Sample size (or number of clusters) by treatment arms
We intend to collect 90 responses per treatment arm.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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Institutional Review Boards (IRBs)

IRB Name
Ashoka University Institutional Review Board
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents


MD5: e16605b6a7bc567f3917d4c4ecde85ec

SHA1: 1879052c295bfcb166fb61bb2975db8976c4c137

Uploaded At: January 27, 2021


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Intervention Completion Date
December 19, 2020, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
December 27, 2020, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials