Who diagnosed and prescribed what? Using provider details to inform observational research

Purpose: To describe how often patients with depression initiating antidepressants receive their depression diagnosis and prescriptions from the same provider and, when simultaneously initiating benzodiazepines, how often both prescriptions come from the same provider. Methods: Using a US healthcare claims database, we created a cohort of adults (18-64 years) with a depression diagnosis who initiated antidepressants. We examined concordance by provider specialty and provider identifier between (a) the first antidepressant prescription fill and most proximal depression diagnosis, and (b) the initial antidepressant and benzodiazepine prescription fills among simultaneous benzodiazepine and antidepressant initiators. Results: Among 245 166 antidepressant initiators with a recent depression diagnosis (female = 67%; median age = 39), the specialty of the provider assigning the depression diagnosis matched the antidepressant prescriber's specialty in 94% of cases with known provider details (provider identifier concordance = 93%). Concordance was higher for adults diagnosed by a general practitioner (98%) or psychiatrist (92%) than for those diagnosed by a psychologist (74%). In simultaneous new users of antidepressants and benzodiazepines (n = 19 371), both prescriptions were issued by the same provider specialty and provider identifier 94% and 93% of the time, respectively. Conclusions: The vast majority of patients who received antidepressant prescriptions and depression diagnoses appear to have received both diagnosis and antidepressants from the same provider, suggesting that when antidepressants are issued around the time a patient is diagnosed with depression, the antidepressant was likely prescribed for depression. In addition, the great majority of patients who simultaneously initiate benzodiazepines appear to do so under the direction of one provider.