Determinants of Clinic Absenteeism: A Novel Method of Examining Distance from Clinic and Transportation

Delayed treatment and non-adherence are associated with inferior prostate cancer (CaP) outcomes. Missed clinic appointments (MA) are one form of non-adherence that may be preventable. We conducted a retrospective cohort study of 1341 scheduled clinic encounters for men referred to an academic urology clinic for evaluation of known or suspected CaP. Driving distance and public transit times were calculated using a Google Distance Matrix API algorithm. Zip code level data regarding socioeconomic status was obtained from the 2013 American Community Survey. Logistic regression multivariate analysis was used to identify MA predictors. Of scheduled clinic encounters, 14% were missed. Public health insurance was associated with MA (Private insurance 10%, Public insurance 19%), (p < 0.01) Calendar month was associated with MA with December showing the highest rate (21.2%) and June the lowest (5.3%) rates. (p = 0.02) Appointments for suspected CaP were more likely to be missed (19.3%) than those for known CaP (10.5%), p < 0.01. Driving distance was inversely associated with rate of MA (CA median 11.8 miles, MA median 10.4 miles, p = 0.04) while public transit times were not (66.7 min for CA, 65.3 min for MA, p = 0.36). Men that missed appointments were from areas with lower household incomes and educational attainment. Patient encounter type, insurance status, and reason for referral remained significantly associated with MA after multivariable adjusted analysis. By computing public transit time to the clinic using a mapping engine, we present a novel way to measure this parameter for studies of urban health care.