INTRODUCTION
Psoriasis patients are often frustrated with the treatment they receive.1-3 The quality-of-life impact of psoriasis is comparable to that of other major medical diseases such as arthritis, hypertension, and diabetes.4-6 The wide range of variation in patient preferences, combined with the complex patient psychology involved, continues to contribute to suboptimal treatment.5,7,8 Low motivation, which contributes to poor adherence
and poor outcomes, can result from fear of medication, dissatisfaction
with the cosmetic effects of medications, or simply lack of hope that psoriasis can be effectively controlled.3,8
Many factors contribute to the need for physicians to have a large arsenal of treatments available for psoriasis. Different patients
prefer different vehicles, and patients may even prefer one vehicle for one body site and a different vehicle for another.9,10 Superpotent corticosteroids are ideal for some body sites but cannot be safely used in more sensitive areas.11 Most corticosteroids cannot be safely used for long periods of time and have to be replaced with other medications, such as calcipotriene,
after a few weeks.11 Some patients have insurance that covers the most expensive branded products, while others do not. Multiple products used together, such as calcipotriene combined with topical steroids, often have synergistic effects, but many patients are more adherent to a simpler regimen.12 All these factors dictate that individualized treatment of psoriasis
is essential. Despite occasional pressures to standardize psoriasis treatment, the latest guidelines continue to recognize that a wide range of monotherapies and combination therapies should be part of the physician’s treatment repertoire.11,13
Treatment of psoriasis continues to evolve rapidly with the introduction of new treatments almost every year. The combinations
that are most often used have not been well characterized in recent years. The purpose of this study is to assess the frequency
with which calcipotriene and other psoriasis drugs are used in combination.
METHODS
The National Ambulatory Medical Care Survey (NAMCS), conducted
by the National Center for Health Statistics, has collected data annually since 1989 on the utilization of ambulatory medical care services in the United States. Using a multistage probability sample design, the NAMCS collects data on a nationally representative
sample of outpatient visits to nonfederally employed physicians who participate in direct patient care. Patient demographics,
diagnoses, medications, and services provided are among the data recorded. Sampling weights are applied to make nationally representative frequency estimates.
This study analyzed all NAMCS visits from 1990 to 2010 with a sole diagnosis of psoriasis (ICD-9 code 696.1). Visits with other diagnoses were excluded to ensure that the prescribed medications were for psoriasis. Psoriasis medications were classified as topical steroids, vitamin D analogues, other topicals, and systemic treatments. Other topicals included calcineurin inhibitors, tar, anthralin, moisturizers, and keratolytics,
including salicylic acid. Systemic treatments included systemic steroids, methotrexate, acitretin, cyclosporine, and biologics. Phototherapy treatments were not assessed in this
