Polypharmacy in dermatology: analysis of a nationally representative sample of 46,273 dermatology patient visits in the United States from 1995 to 2009.

There are no large-scale studies ofpolypharmacy (PP) in dermatology. The authors examined trends in PP (simultaneous use of > or = 4 medications in our study) and associated clinical factors among a nationally representative sample of 46,273 (weighted count +/- standard error [SE]: 617,970,596 +/- 25,187,959) dermatology-related (International Classification of Diseases, Ninth Revision, Clinical Modification codes 680-709) patient visits from 1995 to 2009. Data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Care Survey were examined. The overall frequency (+/- SE) of PP was 8.9% +/- 0.4%. There was almost a doubling in the frequency of PP in dermatology from 1995 to 2009 (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.67-2.44, after controlling for comorbidities and sex). This increase was noted among patients with > 1 diagnoses, and all age groups including the younger than 25 age category (PP frequency +/- SE, 7.4% +/- 0.4%; OR, 1.45; 95% CI, 1.12-1.88), and not just among patients in the geriatric age range with multiple complex dermatologic problems. Some of the most frequent conditions in the PP group included acne, psoriasis, atopic dermatitis, and infections of the skin and subcutaneous tissue, conditions that are known to be affected by psychodermatologic factors. PP among these patients may in part be an indication of their complex presentation caused by psychosocial vs dermatopathologic factors.