Nudging Hard-to-Reach Populations Toward Spanish Colorectal Cancer Screening (JA PreventNCD study)
Abstract
Introduction: Men over 60 are the least likely to participate in the Colorectal Cancer Screening Programme of the Valencia Community (CRCSP-VC). This study assesses three invitation-based behavioural nudges of increasing intensity to boost screening participation among never-screened men over 60 (hard-to-reach population).
Methods: A randomized controlled trial within the CRCSP-VC (Spain, Feb–Sep 2025) targeting never-screened men over 60 from the screening-eligible population, randomly assigned to one control and three intervention groups. The control group (n = 1,600) received the usual invitation (letter plus pre-paid card to accept the invitation; if accepted, the screening test was mailed home); Intervention groups (I) received escalating nudges: I1 (n = 1,600), usual invitation plus a modified letter using behavioural change messages; I2 (n = 1,600), I1 plus choice of pre-paid card or SMS to accept; I3 (n = 1,200), I1 plus direct home delivery of the screening test. Descriptive and multivariate (logit CI95%) analysis of the outcome variable (participation in CRCSP-VC), by region, age and socio-economic status (SES) (Q1=best to Q4=worst). Randomised Control Trial Registry: https://doi.org/10.1186/ISRCTN52248153. Ethics Committee approval (20241220/03/E).
Results: Participation rates were 5.4% (control group), 6.5% (I1), 7.7% (I2), and 19.7% (I3). Compared to controls, adjusted ORs were: I1 (OR1.20; CI 0.73-1.97); I2 (OR1.53; CI 0.94-2.50); and I3 (OR 4.30; CI 2.67-6.95). Participation increases in I3 vs control group in all SES levels (p < 0.05): (Q1: 4.2% vs 19.1%; Q2: 6.3% vs 22.0%; Q3: 1.7%-16.1%; Q4: 8.9% vs 20.8%).
Conclusions: Nudge intensity strongly predicts screening uptake. Directly mailing the screening test to participantśhome produced a four-fold participation increase, with consistent gains across all socioeconomic groups, suggesting this strategy can meaningfully reduce screening inequalities in hard-to-reach populations.
Key messages: • Participation rates increase significantly when the screening test is included directly with the invitation letter.
• Sending the screening test directly with the invitation letter reduces screening inequalities in hard-to-reach populations.
Related
- Improving cancer prevention literacy in a Spanish cancer screening population (JA PreventNCD study)
- A clinical prediction nomogram for hemorrhoid risk in health screening populations in Beijing, China: a retrospective cohort study of 35,256 adults
- Toward Precision Colorectal Cancer Screening: Integrating Clinical Risk Stratification, Molecular Biomarkers, and Artificial Intelligence
- Evaluation of a colorectal cancer screening program composed of successive waves of different tests: The experience of the French Calvados County
- Cost-Effectiveness of Colorectal Cancer Screening Tests: Reply to Response.
BibTeX
@article{molinabarcelo2026nudging,
title = {{Nudging Hard-to-Reach Populations Toward Spanish Colorectal Cancer Screening (JA PreventNCD study)}},
author = {A Molina-Barceló and E Pérez-Sanz and P Romeo-Cervera and I Iturbe-Ormaeche and D Jiménez-Gómez and S Castán-Cameo and M Besó and M Vanaclocha-Espí},
journal = {The European Journal of Public Health},
year = {2026},
month = oct,
doi = {10.1093/eurpub/ckag169.547},
url = {https://doi.org/10.1093/eurpub/ckag169.547},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Nudging Hard-to-Reach Populations Toward Spanish Colorectal Cancer Screening (JA PreventNCD study)
AU - A Molina-Barceló
AU - E Pérez-Sanz
AU - P Romeo-Cervera
AU - I Iturbe-Ormaeche
AU - D Jiménez-Gómez
AU - S Castán-Cameo
AU - M Besó
AU - M Vanaclocha-Espí
PY - 2026
DA - 2026/10/01
JO - The European Journal of Public Health
DO - 10.1093/eurpub/ckag169.547
UR - https://doi.org/10.1093/eurpub/ckag169.547
AB - Introduction: Men over 60 are the least likely to participate in the Colorectal Cancer Screening Programme of the Valencia Community (CRCSP-VC). This study assesses three invitation-based behavioural nudges of increasing intensity to boost screening participation among never-screened men over 60 (hard-to-reach population). Methods: A randomized controlled trial within the CRCSP-VC (Spain, Feb–Sep 2025) targeting never-screened men over 60 from the screening-eligible population, randomly assigned to one control and three intervention groups. The control group (n = 1,600) received the usual invitation (letter plus pre-paid card to accept the invitation; if accepted, the screening test was mailed home); Intervention groups (I) received escalating nudges: I1 (n = 1,600), usual invitation plus a modified letter using behavioural change messages; I2 (n = 1,600), I1 plus choice of pre-paid card or SMS to accept; I3 (n = 1,200), I1 plus direct home delivery of the screening test. Descriptive and multivariate (logit CI95%) analysis of the outcome variable (participation in CRCSP-VC), by region, age and socio-economic status (SES) (Q1=best to Q4=worst). Randomised Control Trial Registry: https://doi.org/10.1186/ISRCTN52248153. Ethics Committee approval (20241220/03/E). Results: Participation rates were 5.4% (control group), 6.5% (I1), 7.7% (I2), and 19.7% (I3). Compared to controls, adjusted ORs were: I1 (OR1.20; CI 0.73-1.97); I2 (OR1.53; CI 0.94-2.50); and I3 (OR 4.30; CI 2.67-6.95). Participation increases in I3 vs control group in all SES levels (p < 0.05): (Q1: 4.2% vs 19.1%; Q2: 6.3% vs 22.0%; Q3: 1.7%-16.1%; Q4: 8.9% vs 20.8%). Conclusions: Nudge intensity strongly predicts screening uptake. Directly mailing the screening test to participantśhome produced a four-fold participation increase, with consistent gains across all socioeconomic groups, suggesting this strategy can meaningfully reduce screening inequalities in hard-to-reach populations. Key messages: • Participation rates increase significantly when the screening test is included directly with the invitation letter. • Sending the screening test directly with the invitation letter reduces screening inequalities in hard-to-reach populations.
SN - 1101-1262
SN - 1464-360X
ER -