Direct and Indirect Effects of Cancer Screening Invitations on Participation in Europe: A Quasi-Experimental Analysis

Organized cancer screening programs (OSPs) in Europe for breast, cervical, and colorectal cancers aim to improve early detection and reduce mortality. This study measures the effects of OSPs on participation and examines cross-program spillovers, as women are often invited to multiple screenings. We construct a regional-level dataset on OSP availability, merged with individual-level data from the European Health Interview Survey (EHIS) covering 122,000 women in 27 countries. We exploit cross-region and age-based variations in eligibility and employ a quasi-experimental difference-in-differences model to measure the causal effect of OSPs. OSPs substantially increase screening participation: mammography rises by 33.20 percentage points (pp) (95% CI: 24.56–41.85), fecal occult blood test (FOBT) by 19.41 pp (95% CI: 13.95–24.88), and pap test by 9.33 pp (95% CI: 5.26–13.41). Positive spillover effects occur when women are invited to two screenings (10 pp (95% CI: 4.81–15.20) for mammography, 3.35 pp (95% CI: 0.56–6.15) for pap test, 7.44 pp (95% CI:2.34–12.55) for FOBT) but targeting three cancers does not yield additional statistically significant gains. These findings highlight the strong impact of OSPs on participation and the value of coordinated screening and communication strategies as Europe expands organized screening to new cancer sites.