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Use of Airtime Incentives to Improve Short Message Service Surveys in Colombia and Tanzania

Not Applicable
Completed
Conditions
Surveys and Questionnaires
Noncommunicable Diseases
Interventions
Other: 1X airtime incentive
Other: 2X airtime Incentive
Other: Lottery airtime incentive
Registration Number
NCT03768934
Lead Sponsor
Johns Hopkins Bloomberg School of Public Health
Brief Summary

This study evaluates the effect of four different airtime incentive amounts on short message service (SMS) survey cooperation, response, refusal and contact rates, as compared to control group, in Colombia and Tanzania.

Detailed Description

Using random digit dialing (RDD) sampling technique, participants were randomized to one of four airtime incentive amounts contingent on them completing the noncommunicable disease risk factor survey. This mobile phone survey will be sent as a short message service (SMS). In SMS surveys, participants use their touch tone key pad to answer written questions. (i.e. If you are male, press 1; If you are female, press 2). This study will be conducted in both Colombia and Tanzania.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
2151
Inclusion Criteria
  • Access to a mobile phone
  • Greater or equal to 18 years of age
  • In Colombia, conversant in the Spanish language. In Tanzania, conversant in the Swahili language.
Exclusion Criteria
  • Less than 18 years of age

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
1X Incentive1X airtime incentive1X airtime incentive
2X incentive2X airtime Incentive2X airtime incentive
Lottery IncentiveLottery airtime incentiveLottery airtime incentive where odds of winning lottery are 1 out of 20
Primary Outcome Measures
NameTimeMethod
Cooperate Rate #1Through study completion, an average of one month

As defined by American Association for Public Opinion Research, cooperation rate is defined as I/(I+P+R) where I is complete interviews, P is partial interviews, and R is refusals and breakoffs.

Response Rate #4Through study completion, an average of one month

As defined by American Association for Public Opinion Research, response rate is defined as (I+P)/(I+P+R+eU) where I is complete interviews, P is partial interviews, R is refusals and breakoffs, and eU is the estimated eligible proportion of unknowns.

Secondary Outcome Measures
NameTimeMethod
Contact Rate #2Through study completion, an average of one month

As defined by American Association for Public Opinion Research, contact rate is defined as (I+P+R)/(I+P+R+eU) where I is complete interviews, P is partial interviews, R is refusals and breakoffs, and eU is the estimated eligible proportion of unknowns.

Refusal Rate #2Through study completion, an average of one month

As defined by American Association for Public Opinion Research, refusal rate is defined as (R)/(I+P+R+eU) where R is refusals and breakoffs, I is complete interviews, P is partial interviews, and eU is the estimated eligible proportion of unknowns.

Trial Locations

Locations (2)

Instituto de Salud Publica Pontificia Universidad Javeriana

🇨🇴

Bogota, D.c., Colombia

Ifakara Health Institute

🇹🇿

Dar Es Salaam, Tanzania

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