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A preference for the similar: evidence from peer mentoring for smoking cessation
Last registered on February 17, 2017

Pre-Trial

Trial Information
General Information
Title
A preference for the similar: evidence from peer mentoring for smoking cessation
RCT ID
AEARCTR-0002020
Initial registration date
February 17, 2017
Last updated
February 17, 2017 2:14 PM EST
Location(s)
Region
Primary Investigator
Affiliation
London School of Economics
Other Primary Investigator(s)
PI Affiliation
University of California, San Francisco
Additional Trial Information
Status
On going
Start date
2016-10-12
End date
2017-07-30
Secondary IDs
ClinicalTrials.gov: ID NCT03048786
Abstract
Although peer effects have been documented in a variety of contexts, little is known about the role played by peer characteristics in mediating those effects. Are people more likely to follow those most similar to them? If so, along what dimensions does similarity matter most? We study this question in the context of peer mentoring for smoking cessation, delivered by former smokers through a text-messaging platform. The platform serves as the basis for a randomized controlled trial to test the effectiveness and appeal of peer mentoring for smoking cessation. The experiment will include about 200 U.S. adult smokers who will be randomly assigned to a peer mentor or not. Participants in the control group will receive automated text messages used in SmokefreeTXT, a nationwide text-messaging service sponsored by the National Cancer Institute (NCI) in which users receive one to five automated messages per day for up to eight weeks. Smokers in the treatment group will receive a modified version of the same automated messages, but with additional personalized messages from a randomly assigned peer mentor. Mentors will provide responses to specific questions or comments a smoker may have after receiving the automated messages. The intervention will last 8 weeks. Our study has two aims. First, we analyze smokers’ preferences for peer mentors to understand which mentor characteristics matter most to them and to investigate the role played by similarity in shaping their preferences. Second, we study whether having a peer mentor similar to themselves and/or close to their own preferences affects (i) their engagement; and (ii) their performance as measured by their quit status.
External Link(s)
Registration Citation
Citation
Toussaert, Severine and Justin White. 2017. "A preference for the similar: evidence from peer mentoring for smoking cessation." AEA RCT Registry. February 17. https://doi.org/10.1257/rct.2020-1.0.
Former Citation
Toussaert, Severine, Severine Toussaert and Justin White. 2017. "A preference for the similar: evidence from peer mentoring for smoking cessation." AEA RCT Registry. February 17. http://www.socialscienceregistry.org/trials/2020/history/14140.
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Experimental Details
Interventions
Intervention(s)
This pilot will include about 200 U.S. adult smokers who will be randomly assigned to a peer mentor or not. Participants in the control group will receive automated text messages used in SmokefreeTXT, a nationwide text-messaging service sponsored by the National Cancer Institute (NCI) in which users receive one to five automated messages per day for up to eight weeks. Smokers in
the intervention group will receive a modified version of the same automated messages from SmokefreeTXT, but with additional personalized messages from an assigned peer mentor. Mentors will provide responses to specific questions or comments a smoker may have after receiving the automated messages. The intervention will last 8 weeks. The study includes primary outcomes to measure engagement and early efficacy of the intervention.
Intervention Start Date
2017-02-03
Intervention End Date
2017-06-30
Primary Outcomes
Primary Outcomes (end points)
We consider two types of outcomes pertaining to a participant's level of engagement during the intervention and smoking status at the end of the intervention. For engagement, our primary outcome measure is the number of days from enrollment since the participant last replied to a message asking about the person’s status (e.g., mood and cravings). Our primary outcome measure for smoking status at the end of the intervention is a dummy variable equal to 1 if a participant tested negative on a salivary cotinine test administered 3 months after the participant's quit date.
Primary Outcomes (explanation)
See attached document for a description of the other outcomes we will consider.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
See attached document for a complete description of the intervention and design.
Experimental Design Details
Randomization Method
random generator (in office by a computer)
Randomization Unit
individual
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
about 200 smokers split evenly across treatment and control
34 mentors
Sample size: planned number of observations
100 observations for our engagement and performance outcomes. For the analysis of preferences for peer mentors, see document attached.
Sample size (or number of clusters) by treatment arms
100 in treatment, 100 in control
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
IRB Laurel Heights Panel, University of California San Francisco
IRB Approval Date
2016-05-24
IRB Approval Number
16-18577
Analysis Plan
Analysis Plan Documents
Description of the Study and Data Analysis

MD5: 7dbb2432644c4a49e065a9ce77390d16

SHA1: 47e5c9d21ec830030c3e6247dd32e62cf79a4d72

Uploaded At: February 17, 2017

Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
No
Is 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