The study is a randomized parallel experiment with two non-overlapping intervention groups and one control group. The study is registered in the US National Library of Medicine’s ClinicalTrials.gov and the American Economic Association’s Registry for Randomized Controlled Trials. The main outcomes of interest are predicted CVD risk, risk factors, health care management of CVD, CVD-related behaviors, perceptions of CVD risk and knowledge of CVD risk factors.
Interventions
Information intervention
The respondents in this group were given personalized information regarding their risk of developing a CVD in the next 10 years, predicted from the information on their risk factors. This aims to assess if the respondents’ risk perceptions and health behavior change after they are given this information.
Lottery intervention
In the second treatment group, the respondents were given a chance to enter a raffle with a monetary prize, on the condition that they go for a checkup to a rural health unit or city health center (RHU/CHC). The intervention aims to assess how the RHUs/CHCs implement the Philippine Package of Essential Non-Communicable Disease Prevention (PhilPEN) protocol.
Setting
Nueva Ecija, which is located 180 km north of Manila, was chosen to be the site of the study because its poverty rate is higher than the national average (29.6% as compared to the national rate of 26.3% in 2015). The poor would most likely visit RHUs and CHCs that are the main implementers of the PhilPEN protocol. Nueva Ecija is also part of Central Luzon, which is one of the regions with the highest prevalence of major CVD risk factors, such as high blood glucose and smoking (FNRI-DOST, 2015).
Sampling
Adults 40 to 70 years of age at the time of the survey and have not been diagnosed of a heart condition or diabetes are the target respondents of the survey. Over 5,000 respondents were sampled from 304 barangays in Nueva Ecija. The barangays were randomly assigned to the treatment groups or the control group.