Geospatial barriers to health care access for breast cancer diagnosis in sub-Saharan African settings: the African Breast Cancer - Disparities in Outcomes (ABC-DO) Cohort Study.

We examined the geospatial dimension of delays to diagnosis of breast cancer in a prospective study of 1541 women newly diagnosed in the African Breast Cancer - Disparities in Outcomes (ABC-DO) Study. Women were recruited at cancer treatment facilities in Namibia, Nigeria, Uganda, and Zambia. The baseline interview included information used to generate the geospatial features: urban/rural residence, travel mode to treatment facility, and straight-line distances from home to first care provider and to diagnostic/treatment facility, categorized into country/ethnicity (population)-specific quartiles. These factors were investigated in relation to delay in diagnosis (≥3 months since first symptom) and late stage at diagnosis (TNM: III, IV) using logistic regression, adjusted for population group and sociodemographic characteristics. The median (interquartile range) distances to first provider and diagnostic and treatment facilities were 5 (1-37), 17 (3-105), and 62 (5-289) kms, respectively. The majority had a delay in diagnosis (74%) and diagnosis at late stage (64%). Distance to first provider was not associated with delay in diagnosis or late stage at diagnosis. Rural residence was associated with delay, but the association did not persist after adjustment for sociodemographic characteristics. Distance to the diagnostic/treatment facility was associated with delay (highest vs lowest quartile: Odds Ratio (OR)=1.56, 95% confidence interval (CI)=1.08-2.27) and late stage (overall: OR=1.47, CI=1.05-2.06; without Nigerian hospitals where mostly local residents were treated: OR=1.73, CI=1.18-2.54). These findings underscore the need of measures addressing the geospatial barriers to early diagnosis in sub-Saharan African settings, including providing transport or travel allowance and decentralizing diagnostic services.