The association between depression and ambulatory care utilization is unclear. The authors sought to determine the association between untreated depression and ambulatory care utilization, including the extent to which care is fragmented, or spread across providers. The authors conducted a longitudinal study using data from the nationwide REasons for Geographic and Racial Differences in Stroke study linked to Medicare fee-for-service claims (N = 1412). They categorized participants into three study groups, based on self-reported depressive symptoms (Center for Epidemiological Studies Depression Scale score ≥ 4) and a medication inventory for antidepressants: Symptomatic Untreated (SU), Symptomatic Treated (ST), and Asymptomatic Treated (AT). The authors used descriptive statistics to characterize ambulatory care patterns by study group. They determined the association between the study group and fragmentation score (with high fragmentation defined as a reversed Bice-Boxerman Index ≥ 0.85) using multivariable logistic regression. All groups had similar numbers of primary care visits, but the SU group had the fewest specialist visits. The SU group had the lowest proportion of participants who received care from a psychiatrist (3.4% vs. 10.7% for ST and 11.9% for AT, pairwise P-values < 0.001). The SU group was the least likely to have highly fragmented care (adjusted odds ratio 0.68; 95% confidence interval 0.48, 0.95, compared with the ST group). These results suggest that older adults with untreated depression are not engaged in excess care-seeking behaviors. Rather, the results suggest undertreatment of depression in primary care and underutilization of psychiatric care.
Keywords: Medicare; ambulatory care; depression; fragmentation.