Patient Portal Use and Cancer Screening in the United States: Individual Associations and Population Impact.

ObjectivesCancer screening uptake in the United States remains below national targets despite established screening recommendations. Patient portals may support preventive care delivery, but their association with cancer screening uptake and population-level contribution remains unclear. We evaluated the association between patient portal use and breast, cervical, and colorectal cancer screening among screening-eligible U.S. adults.MethodsWe conducted a cross-sectional study using pooled data from the nationally representative Health Information National Trends Survey. Screening-eligible adults were defined according to U.S. Preventive Services Task Force criteria for breast, cervical, and colorectal cancer screening. The primary exposure was self-reported patient portal use within the prior 12 months. Outcomes included receipt of breast, cervical, and colorectal cancer screening. Survey-weighted modified Poisson regression was used to estimate adjusted prevalence ratios (aPRs), adjusting for sociodemographic and clinical characteristics. Adjusted absolute differences were estimated using marginal standardization, and population attributable risk percent (PARP) was calculated to estimate the population-level contribution of portal use.ResultsAmong 23,920 respondents, 13,210 (55.2%) reported patient portal use. Portal users had higher screening uptake than non-users for breast cancer screening (85.7% vs 75.1%; p<0.001), cervical cancer screening (83.8% vs 73.7%; p<0.001), and colorectal cancer screening (84.0% vs 72.5%; p=0.002). After adjustment, portal use was associated with higher prevalence of breast cancer screening (aPR 1.15, 95% CI 1.05-1.27; p=0.004) and cervical cancer screening (aPR 1.12, 95% CI 1.04-1.20; p=0.002), with a more modest association for colorectal cancer screening (aPR 1.08, 95% CI 0.99-1.17; p=0.07). Adjusted absolute differences associated with portal use were +14.3%, +12.9%, and +9.0% for breast, cervical, and colorectal cancer screening, respectively. PARP estimates were 7.7%, 6.9%, and 3.6%, respectively.ConclusionPatient portal use was associated with higher uptake of breast and cervical cancer screening, with a more modest and not statistically significant association for colorectal cancer screening after adjustment. Although portal engagement may support preventive care delivery, its population-level contribution to screening uptake was modest, suggesting that portal-based strategies should be paired with broader interventions addressing access, digital literacy, and structural barriers to cancer screening.