Trial Outcomes & Findings for Trial to Evaluate the Impact of Various Interventions to Increase the Uptake of Surveillance Mammography in Eligible Women in Singapore (NCT NCT06733155)

Last Updated: 2026-07-07

Results Overview

Primary endpoint: Comparison of the proportion of women who undergo surveillance mammography among participants in Arms 2-5 versus Arm 1 (control arm).

Recruitment status

COMPLETED

Study phase

Target enrollment

12000 participants

Primary outcome timeframe

4 months from randomization

Results posted on

2026-07-07

Participant Flow

Recruitment Status: Completed Study Period: September 16, 2024 - December 31, 2024 Location: NUHS, Singapore

Assessed for eligibility: 12,931 (A) Active NUHS app users in past 12 months: 9,327 Incomplete mailing address: 311 Other administrative exclusions: 16 Total randomized into 5 Arms (Arm 1 to 5 in 2:1:1:1:1) : 9,000 (B) Not active NUHS app users in past 12 months: 3,604 Randomly selected into non-interventional NI arm: 3,000

Participant milestones

Participant milestones
Measure	Observational Arm Does not receive any mailer reminder to go for mammogram.	Arm 1 (Control) Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram Only reminder mailer: Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram.	Arm 2: Financial Incentive Receives mail reminder + a $10 voucher for completing a mammogram within three months. Financial intervention: Participants completing the mammogram within the study end date will receive a $10 voucher.	Arm 3: Lottery Incentive Receives mail reminder + chance to win a $5000 lottery for completing the screening within three months. Lottery intervention: Participants completing the mammogram within the study end date will receive a chance to win a $5000 lottery.	Arm 4: Health Messaging Receives mail reminder + QR code to a 60-second video from an influential person, available in four languages (English, Chinese, Malay, Tamil). Health Messages: Participants will receive a less than 5 minute long video from an influential person. The video will be available in four languages (English, Chinese, Malay, Tamil).	Arm 5: Personal Health Concierge Receives mail reminder + a dedicated hotline for scheduling mammograms with the help of a health concierge over eight weeks. Personal Health Concierge: Participants will be able to call a dedicated hotline for scheduling mammograms with the help of a health concierge over eight weeks of receive the the mailer.
Overall Study STARTED	3000	3000	1500	1500	1500	1500
Overall Study COMPLETED	3000	3000	1500	1500	1500	1500
Overall Study NOT COMPLETED	0	0	0	0	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Arm 1 (Control) n=3000 Participants Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram Only reminder mailer: Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram.	Arm 2: Financial Incentive n=1500 Participants Receives mail reminder + a $10 voucher for completing a mammogram within three months. Financial intervention: Participants completing the mammogram within the study end date will receive a $10 voucher.	Arm 3: Lottery Incentive n=1500 Participants Receives mail reminder + chance to win a $5000 lottery for completing the screening within three months. Lottery intervention: Participants completing the mammogram within the study end date will receive a chance to win a $5000 lottery.	Arm 4: Health Messaging n=1500 Participants Receives mail reminder + QR code to a 60-second video from an influential person, available in four languages (English, Chinese, Malay, Tamil). Health Messages: Participants will receive a less than 5 minute long video from an influential person. The video will be available in four languages (English, Chinese, Malay, Tamil).	Arm 5: Personal Health Concierge n=1500 Participants Receives mail reminder + a dedicated hotline for scheduling mammograms with the help of a health concierge over eight weeks. Personal Health Concierge: Participants will be able to call a dedicated hotline for scheduling mammograms with the help of a health concierge over eight weeks of receive the the mailer.	Observational Arm n=3000 Participants Non-randomised, Non-interventional (NI) arm	Total n=12000 Participants Total of all reporting groups
Sex/Gender, Customized Females	3000 Participants n=20 Participants	1500 Participants n=20 Participants	1500 Participants n=40 Participants	1500 Participants n=5 Participants	1500 Participants n=9 Participants	3000 Participants n=6 Participants	12000 Participants n=6 Participants
Age, Continuous	62 years n=20 Participants	62 years n=20 Participants	62 years n=40 Participants	62 years n=5 Participants	62 years n=9 Participants	63 years n=6 Participants	62 years n=6 Participants
Age, Customized 50-59	1023 Participants n=20 Participants	514 Participants n=20 Participants	544 Participants n=40 Participants	518 Participants n=5 Participants	529 Participants n=9 Participants	812 Participants n=6 Participants	3940 Participants n=6 Participants
Age, Customized 60-69	1977 Participants n=20 Participants	986 Participants n=20 Participants	956 Participants n=40 Participants	982 Participants n=5 Participants	971 Participants n=9 Participants	2188 Participants n=6 Participants	8060 Participants n=6 Participants
Race/Ethnicity, Customized Chinese	2236 Participants n=20 Participants	1147 Participants n=20 Participants	1112 Participants n=40 Participants	1132 Participants n=5 Participants	1154 Participants n=9 Participants	2169 Participants n=6 Participants	8950 Participants n=6 Participants
Race/Ethnicity, Customized Indian	220 Participants n=20 Participants	109 Participants n=20 Participants	111 Participants n=40 Participants	96 Participants n=5 Participants	103 Participants n=9 Participants	245 Participants n=6 Participants	884 Participants n=6 Participants
Race/Ethnicity, Customized Malay	379 Participants n=20 Participants	171 Participants n=20 Participants	181 Participants n=40 Participants	182 Participants n=5 Participants	176 Participants n=9 Participants	411 Participants n=6 Participants	1500 Participants n=6 Participants
Race/Ethnicity, Customized Others	165 Participants n=20 Participants	73 Participants n=20 Participants	96 Participants n=40 Participants	90 Participants n=5 Participants	67 Participants n=9 Participants	175 Participants n=6 Participants	666 Participants n=6 Participants
Housing Type Public	2664 Participants n=20 Participants	1325 Participants n=20 Participants	1298 Participants n=40 Participants	1323 Participants n=5 Participants	1320 Participants n=9 Participants	2734 Participants n=6 Participants	10664 Participants n=6 Participants
Housing Type Private	336 Participants n=20 Participants	175 Participants n=20 Participants	202 Participants n=40 Participants	177 Participants n=5 Participants	180 Participants n=9 Participants	266 Participants n=6 Participants	1336 Participants n=6 Participants
Proximity to primary care clinic with mammogram facility <5 km	2951 Participants n=20 Participants	1473 Participants n=20 Participants	1481 Participants n=40 Participants	1484 Participants n=5 Participants	1491 Participants n=9 Participants	2961 Participants n=6 Participants	11841 Participants n=6 Participants
Proximity to primary care clinic with mammogram facility >5 - <10 km	49 Participants n=20 Participants	27 Participants n=20 Participants	19 Participants n=40 Participants	16 Participants n=5 Participants	9 Participants n=9 Participants	39 Participants n=6 Participants	159 Participants n=6 Participants
Mean interval from last mammogram	5.3 years n=20 Participants	5.3 years n=20 Participants	5.3 years n=40 Participants	5.4 years n=5 Participants	5.6 years n=9 Participants	6.2 years n=6 Participants	5.5 years n=6 Participants

PRIMARY outcome

Timeframe: 4 months from randomization

Primary endpoint: Comparison of the proportion of women who undergo surveillance mammography among participants in Arms 2-5 versus Arm 1 (control arm).

Outcome measures

Outcome measures
Measure	Arm 1 (Control) n=3000 Participants Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram Only reminder mailer: Receives a mail reminder with basic information about breast cancer and instructions on scheduling a mammogram.	Arm 2: Financial Incentive n=1500 Participants Receives mail reminder + a $10 voucher for completing a mammogram within three months. Financial intervention: Participants completing the mammogram within the study end date will receive a $10 voucher.	Arm 3: Lottery Incentive n=1500 Participants Receives mail reminder + chance to win a $5000 lottery for completing the screening within three months. Lottery intervention: Participants completing the mammogram within the study end date will receive a chance to win a $5000 lottery.	Arm 4: Health Messaging n=1500 Participants Receives mail reminder + QR code to a 60-second video from an influential person, available in four languages (English, Chinese, Malay, Tamil). Health Messages: Participants will receive a less than 5 minute long video from an influential person. The video will be available in four languages (English, Chinese, Malay, Tamil).	Arm 5: Personal Health Concierge n=1500 Participants Receives mail reminder + a dedicated hotline for scheduling mammograms with the help of a health concierge over eight weeks. Personal Health Concierge: Participants will be able to call a dedicated hotline for scheduling mammograms with the help of a health concierge over eight weeks of receive the the mailer.
Comparison of Mammogram Uptake Between Intervention Arms (2-5) and Control Arm (Arm 1)	337 Participants	182 Participants	170 Participants	162 Participants	207 Participants

SECONDARY outcome

Timeframe: 4 months from randomization

Comparison of the proportion of women who undergo surveillance mammography among participants in Non-Interventional Arm (NI arm) versus Arm 1 (control arm).