INTRODUCTION
Negative health outcomes stemming from poor medication adherence account for 36% to 69% of yearly hospital admissions and increase healthcare costs by about $100 billion United States (US) dollars a year.1,2 The prevalence of poor drug adherence to topical treatments is high in dermatology.3 Improving patient adherence can improve disease severity and quality of life in several dermatologic diseases such as acne, atopic dermatitis (AD), and psoriasis.4-7
Poor adherence to medications may also be related in part to the length of time between the initial and return office visit after prescription of a new medication. Adherence increases around the time of an office visit, and is generally greater near the day of a scheduled office visit before decreasing rapidly in the days afterwards.8,9 Shorter times to the first follow up are associated with better treatment adherence.8
Despite the evidence that shorter times to first follow up improve adherence, traditionally physicians often do not have patients return for 2 months or longer after starting a new prescription. The purpose of this study is to determine the time interval from prescription of a new medication until the next recommended return visit in US patients with acne, AD, and psoriasis.
Poor adherence to medications may also be related in part to the length of time between the initial and return office visit after prescription of a new medication. Adherence increases around the time of an office visit, and is generally greater near the day of a scheduled office visit before decreasing rapidly in the days afterwards.8,9 Shorter times to the first follow up are associated with better treatment adherence.8
Despite the evidence that shorter times to first follow up improve adherence, traditionally physicians often do not have patients return for 2 months or longer after starting a new prescription. The purpose of this study is to determine the time interval from prescription of a new medication until the next recommended return visit in US patients with acne, AD, and psoriasis.
METHODS
The Center for Disease Control and Prevention conducts the National Ambulatory Medical Care Survey (NAMCS), a yearly survey that queries physicians primarily in the ambulatory setting who are not federally employed. Physicians who are queried log data in a random week of every year. The logged data includes physician diagnosis, interval until patients return, and medications prescribed. As part of its structure, the survey uses a three-stage probability sampling design. 112 primary sampling units (PSU) are created on the basis of geographic region as part of the first stage. Physicians are then separated into specialty groups within each PSU in the second stage. Patient visits within individual practices are examined in the third stage. Each visit is given an inflation factor, the patient visit weight, which takes into account the probabilities of selection at each stage, adjusts for nonresponses, and post-ratio adjustments, and incorporates a weight smoothing technique.10-12
We analyzed this data set for all visits where International Classification of Diseases Ninth Edition (ICD-9) codes 706.1, 696.1, 691.8, and ICD-10 codes L70.0, L40.0, and L20.9 were the primary diagnosis. These represent diagnoses of other acne, other psoriasis, other atopic dermatitis, acne vulgaris, psoriasis vulgaris, and atopic dermatitis (unspecified), respectively.13
We analyzed this data set for all visits where International Classification of Diseases Ninth Edition (ICD-9) codes 706.1, 696.1, 691.8, and ICD-10 codes L70.0, L40.0, and L20.9 were the primary diagnosis. These represent diagnoses of other acne, other psoriasis, other atopic dermatitis, acne vulgaris, psoriasis vulgaris, and atopic dermatitis (unspecified), respectively.13
