AbstractBackgroundDespite the recognized benefits of structured cancer screening, tests outside organized screening programs are common. Comprehensive reports on outside program screening in Europe are lacking, but the Flemish breast cancer (BC) and colorectal cancer (CRC) screening programs monitor data on non-organized tests prescribed by GPs and specialists.MethodsUsing data at aggregated level, logistic regression was used to examine the relationship between health care utilization and screening coverage in 308 Flemish municipalities during 2015–18.ResultsWith regards to BC, municipalities with higher rates of gynecologists’ visits had lower odds of coverage inside (−8%) and higher odds of coverage outside (+17%) the program. By contrast, municipalities with higher rates of GP visits, had higher odds of coverage inside (+6%) and lower odds of coverage outside (−7%) the program. As for CRC, municipalities with higher rates of visits gastroenterologists’ visits had lower odds of coverage inside (−3%). Instead, municipalities with higher rates of GP visits, had higher odds of coverage both inside (+2%) and outside (+5%) the program. Municipalities with higher percentages of people with chronic conditions had higher odds of coverage within both the BC and CRC programs (+5% and +3%), and lower odds of outside screening (−7% and −6%). Municipalities with higher percentages of people 65+ with dementia and with mood disorders had, respectively, higher odds (+13% and +5%) and lower odds (−3% and −4%) of coverage inside both the BC and CRC programs.ConclusionOur findings underscore the impact of healthcare utilization on cancer screening coverage at the municipal level in Flanders.