Factors Influencing Timely Follow-up After Inconclusive Screening Mammograms at a 3D Mobile Mammography Center

Background  The Linda Fenner 3D Mobile Mammography Center (LFMMC) was created to reduce disparities in screening for breast cancer and improve survival for women with limited access to such screening. However, for screened patients requiring follow-up testing, research has shown a wide variation of time taken to access diagnostic imaging, especially among uninsured women. Aim To explore factors associated with longer (>30 days) time intervals to complete diagnostic imaging after screening.  Methods This was a retrospective cohort study using data from the LFMMC from 2014 to 2022. Women living in Miami-Dade County (MDC), over the age of 40, uninsured, and requiring follow-up diagnostic imaging after breast cancer screening were included. Factors assessed included women's age, area of residency, race, primary language spoken, marital status, body mass index (BMI), history of hormone use, previous mammogram, breast implants, breast cancer in immediate family, past breast surgery, and menopause status. The interval of time taken between receiving a screening mammogram result and completing further diagnostic imaging was the outcome, dichotomized into greater than 30 days (longer follow-up time) or up to 30 days. Multivariable binary logistic regression models were used to estimate independent associations (odds ratio [OR] and 95% confidence interval [CI]) of selected factors and longer time intervals to complete diagnostic imaging follow-up.  Results We analyzed data from 926 eligible patients. The mean age was 50.1 years (SD = 8.81). A majority were white (n = 643; 69%), Hispanic (n = 698; 72%), had a history of previous mammograms (n = 589; 64%), and had no family history of breast cancer (n = 757; 82%). About 50% had a diagnostic follow-up exam performed after 30 days (median time to follow-up was 32, interquartile range 23-46 days). Single women had 30% lower odds of longer follow-up than married women (OR 0.70, 95% CI 0.52-0.93). Residents of Homestead (a city within Miami-Dade County) had 2.5 higher odds of having a longer time to follow-up, compared to non-Homestead residents (OR 2.50, 95% CI 1.60-3.90). Conclusions Being single was associated with a shorter time to follow up with diagnostic imaging while residing in Homestead was associated with a longer time to follow-up. Further research with a larger sample and further details on patient characteristics are warranted to better identify targets for interventions aimed at optimizing continuity of care and detecting breast cancer at earlier stages.