Background Prior work has not studied the effects of transportation accessibility and patient factors on clinic non-arrival.

Objectives Our objectives were: (1) to evaluate transportation characteristics and patient factors associated with clinic non-arrival, (2) to evaluate the comparability of bus and car drive time estimates, and (3) to evaluate the combined effects of transportation accessibility and income on scheduled appointment non-arrival.

Methods We queried electronic administrative records at an urban general pediatrics clinic. We compared patient and transportation characteristics between arrivals and non-arrivals for scheduled appointments using multivariable modeling.

Results There were 15 346 (29.8%) clinic non-arrivals. In separate car and bus multivariable models that controlled for patient and transit characteristics, we identified significant interactions between income and drive time, and clinic non-arrival. Patients in the lowest quartile of income who were also in the longest quartile of travel time by bus had an increased OR of clinic non-arrival compared with patients in the lowest quartile of income and shortest quartile of travel time by bus (1.55; P<0.01). Similarly, patients in the lowest quartile of income who were also in the longest quartile of travel time by car had an increased OR of clinic non-arrival compared with patients in the lowest quartile of income and shortest quartile of travel time by car (1.21, respectively; P<0.01).

Conclusions Clinic non-arrival is associated with the interaction of longer travel time and lower income.