Transportation Insecurity, Social Support, and Adherence to Cancer Screening.

Importance: Transportation insecurity and lack of social support are 2 understudied social determinants of health that contribute to excess morbidity, mortality, and acute health care utilization. However, whether and how these social determinants of health are associated with cancer screening has not been determined and has implications for preventive care. Objective: To determine whether transportation insecurity or social support are associated with screening adherence for colorectal, breast, and cervical cancer. Design, Setting, and Participants: This cohort study used data from the publicly available 2018 in-person National Health Interview Survey (NHIS) comprising a noninstitutionalized, civilian adult population of the United States. Participants included adults eligible for colorectal, breast, or cervical cancer screening who participated in the in-depth NHIS interview (1 selected per household). Data were acquired in December 2023 and analyzed through July 31, 2024. Exposures: Transportation insecurity, represented dichotomously as adults who reported that they have or have not delayed medical care in the past year due to transportation difficulties, and neighborhood social support, represented as factor scores derived from 4 Likert-type questions. Main Outcomes and Measures: The primary outcome was adherence to the US Preventive Services Task Force screening recommendations in place during 2018 for colorectal, breast, and cervical cancer. Results: In 2018, of 25 417 NHIS respondents (55% female), 660 (3%) reported delaying medical care because they did not have transportation. In fully adjusted models, transportation insecurity was associated with adherence to breast cancer screening (odds ratio [OR], 0.59 [95% CI, 0.40-0.86]) but not to colorectal (OR, 0.87 [95% CI, 0.65-1.15]) or cervical (OR, 0.73 [95% CI, 0.46-1.13) cancer screening. Social support was associated with colorectal (OR, 1.12 [95% CI, 1.06-1.17]) and breast (OR, 1.13 [95% CI, 1.05-1.22]) cancer screening but not with cervical cancer screening (OR, 1.01 [95% CI, 0.93-1.10]). There were no significant interactions between transportation insecurity and social support for any cancer screening. Conclusions and Relevance: The presence of transportation insecurity was associated with a 41% reduction in the odds of breast cancer screening. Clinicians should consider screening for transportation needs at the time of mammography referral, as patients may be eligible for programs that can assist with medical transportation needs.