The study population consisted of 274 administrative regions (clusters) in Trivandrum district, Kerala, southern Indian. 133 clusters were randomly assigned to the intervention arm (3 rounds of clinical breast examination conducted 3 years apart) and were compared to the remaining 141 clusters assigned to a control arm that received standard of care. The eligibility criteria were all healthy subjects aged 30 to 69, without a personal history of breast cancer. Informed consent was signed by each participant. The intervention arm consisted of 55,843 participants and the control group consisted of 59,447 participants.
