Trial to Evaluate the Impact of Various Interventions to Increase the Uptake of Surveillance Mammography in Eligible Women in Singapore

Breast cancer is the most common cancer among women in Singapore, with more than 70 women out of every 100,000 being diagnosed each year. Early detection through regular mammograms can significantly reduce deaths from breast cancer. Although Singapore has had a national breast cancer screening program (now part of the Screen for Life initiative) for over 20 years, and the government offers substantial subsidies to make screening more affordable, participation remains low at only 30-40%. This low uptake is due to factors like fear, lack of awareness, cultural beliefs, and a perceived low risk of breast cancer. To be effective on a large scale, at least 70% of women need to participate in regular mammography screenings. While researchers in Singapore and Asia have studied the reasons behind low screening rates, there is still a lack of large-scale studies that test different strategies to increase mammography participation in these regions.

This randomized controlled trial will recruit 12,000 women aged 50-69 who have not undergone a mammogram in the past two years. Participants will be randomized into five intervention arms and one observational group (non-mailer reminder receiving, n=3000). The interventions include: direct mail reminder (Arm 1, control, n=3000), financial incentive (Arm 2, n=1500), lottery incentive (Arm 3, n=1500), health messaging from an influential figure (Arm 4, n=1500), and personal health concierge for appointment scheduling (Arm 5, n=1500). A post-intervention telephone survey will assess intervention effectiveness.

The primary outcome is mammogram uptake across intervention arms. Subgroup analyses will evaluate differences in uptake by sociodemographic factors, such as ethnicity and socioeconomic status. A cost-effectiveness analysis will assess the financial viability of each intervention.

This is the first large-scale study in Singapore and Asia to compare multiple interventions to boost mammography uptake. Findings will provide evidence-based strategies to improve breast cancer screening participation, potentially reducing breast cancer mortality and informing future public health policy.

This study aims to evaluate different interventions to boost breast cancer screening (mammography) participation among women in Singapore, aged 50-69, using data from the National University Health System (NUHS). A total of 12,000 eligible women will be randomized into one control arm and four experimental arms, receiving different combinations of reminders and incentives. The study will use data from the NUHS electronic health records (EPIC) and NUHS app to monitor mammogram completion rates, exploring the effectiveness of each intervention.

Study Arms:

Control Group (Direct Mail Reminder): Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram.

Financial Incentive Group: Mail reminder + a $10 voucher for completing a mammogram within three months.

Lottery Incentive Group: Mail reminder + chance to win a $5000 lottery for completing the screening within three months.

Health Messaging Group: Mail reminder + QR code to a 60-second video from an influential person, available in four languages (English, Chinese, Malay, Tamil).

Personal Health Concierge Group: Mail reminder + a dedicated hotline for scheduling mammogram with the help of a health concierge over eight weeks.

Selection and Randomization:

Eligible participants will be selected from over 500,000 registered users of the OneNUHS app. Randomization will be done using a random number generator, with control and experimental arms receiving a 2:1 ratio. Data collected include basic demographic details and mammogram history, extracted securely from the EPIC system.

Data Collection:

Women in each arm will receive a physical mailer and three push notifications over three weeks, instructing them to schedule a mammogram at any approved screening center. Data on mammogram attendance will be extracted from EPIC post-study, and a subset of participants will be surveyed to gather feedback.

Primary and Secondary Endpoints:

The study will compare mammogram participation rates between the control and experimental arms, with secondary analyses exploring the impact of ethnicity, age, and income (via housing type) on outcomes. Additionally, a cost-effectiveness analysis will assess the impact of interventions on breast cancer detection and healthcare savings.

Follow-up and Evaluation:

A post-trial telephone survey of 750 participants will gather insights into their response to the interventions. The study aims to provide actionable insights into effective, scalable interventions to improve mammography uptake and reduce breast cancer mortality in Singapore.

Eligibility Criteria:
Inclusion Criteria:

* Singaporean citizen
* Age 50-69
* Registered as a patient at the National University Hospital
* Registered and active user of OneNUHS App
* Signed up with Healthier SG with a primary care provider within the NUHS Primary Care Network

Exclusion Criteria:

* Diagnosis of breast cancer in EPIC
* Mammogram done in the past 24 months in EPIC