Leveraging Mobile Technology and Financial Incentives to Increase Non-Communicable Disease Screening Rates in Tanzania
Last registered on December 06, 2018


Trial Information
General Information
Leveraging Mobile Technology and Financial Incentives to Increase Non-Communicable Disease Screening Rates in Tanzania
Initial registration date
March 07, 2018
Last updated
December 06, 2018 11:11 AM EST

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Primary Investigator
UC Berkeley
Other Primary Investigator(s)
PI Affiliation
UC Berkeley
PI Affiliation
University of Dodoma
Additional Trial Information
In development
Start date
End date
Secondary IDs
The epidemiological transition has resulted in an increased burden of non-communicable diseases such as hypertension throughout the developing world. As countries adapt to this new environment, they must find cost-effective ways of screening for, and treating these diseases. With the proliferation of mobile technology as well as the increased evidence for the effectiveness of cash transfers we will be conducting a randomized-controlled trial in rural Tanzania to examine the usage of an SMS-based approach of informing individuals of the dangers of non-communicable diseases and offering financial incentives for hypertension and diabetes screening. Beyond estimating the overall impact of this program, we will measure how much of the impact is derived from offsetting the opportunity cost of screening as well as the impact from providing negative prices. The study includes four arms: (1) Pure Control, (2) Information Only, (3) Information + Small Transfer, and (4) Information + Larger Transfer. Due to the small area where our study takes place, we will also be examining how information spreads between individuals in the treatment and pure control arms to assess the effects of social networks on program success.
External Link(s)
Registration Citation
Dow, William, Fredrick Manang and Zachary Olson. 2018. "Leveraging Mobile Technology and Financial Incentives to Increase Non-Communicable Disease Screening Rates in Tanzania." AEA RCT Registry. December 06. https://www.socialscienceregistry.org/trials/2768/history/38480
Experimental Details
(1) Pure Control: The pure control group will receive no intervention. If they attend a clinic during the intervention for screening, it will be provided free of charge.

(2) Information Only: The information only arm will receive a series of text messages about the importance of hypertension and diabetes screening as well as the location of the nearest clinic where they can receive free screening within one month of the first text message.

(3) Information + Small Cash Transfer: This arm will receive the same text messages as arm (2) and will also be offered a small cash transfer if they go to a clinic for screening.

(4) Information + Large Cash Transfer: This arm will receive the same text messages as arm (2) and will also be offered a cash transfer approximately 50%-100% larger than that from arm (3).

All individuals who attend clinics will be screened based on national protocols using both manual and electronic sphygmomanometers for hypertension and random blood glucose tests for diabetes. All individuals who screen positive for hypertension or diabetes will be referred for appropriate care based on national care algorithms.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
1. Being screened for hypertension during the trial period
2. Proportion of individuals determined to be hypertensive
3. Proportion of individuals determined to be diabetic
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
This is randomized controlled trial using 1,000 individuals from the Chamwino District Demographic Surveillance Area (DSA) for treatment arms and using all remaining sample as a pure control.

1. Baseline Data - Data was collected by the Chamwino District (DSA) in the fall of 2016.

2. Randomization and Intervention - Individuals over the age of 35 with access to a cellular phone will be randomly assigned into one of the four study arms stratified by gender and age group.

3. Endline Data - Endline data will be collected at the clinic for individuals who attend screening. Follow-up surveys (and screening) will be conducted at the households for individuals who did not respond to the intervention as well as individuals who screened positive for hypertension and/or diabetes one month after the intervention.
Experimental Design Details
Not available
Randomization Method
Stratified randomization will be done in office by a computer using stata
Randomization Unit
Randomization will be done at the household level.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
(1) Pure Control - 2500
(2) Information Only - 333
(3) Information + Small Transfer - 333
(4) Information + Large Transfer - 334
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
With current screening rates at around 5%, we should be able to detect a 5 percentage point difference between the pure control arm (2500 individuals) and any treatment arm (~333 individuals). Assuming a take-up of 20% screening in the information arm, we would be able to detect a ten percentage point change given 333 people in each treatment arm (alpha=.05, power=.8, two-sided chi-squared test).
IRB Name
UC Berkeley Committee for Protection of Human Subjects
IRB Approval Date
IRB Approval Number