Trends in Systemic Psoriasis Treatment Therapies from 1993 Through 2010

August 2014 | Volume 13 | Issue 8 | Original Article | 917 | Copyright © August 2014


Meredith K. Shaw,a Scott A. Davis MA,a Steven R. Feldman MD PhD,a,b,c and Alan B. Fleischer Jr. MDa

aDepartment of Dermatology, Wake Forest School of Medicine, Winston-Salem, NC
bDepartment of Pathology, Wake Forest School of Medicine, Winston-Salem, NC
cDepartment of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC

Abstract
BACKGROUND: Moderate-to-severe psoriasis generally requires systemic therapy, and is often undertreated.
OBJECTIVE: To determine and analyze what courses of treatment and in what frequency are being utilized to combat psoriasis in the United States.
METHODS: Analysis of data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) of the National Center for Health Statistics. Data were analyzed to examine the prevalence of different therapy techniques to combat psoriasis from 1993 through 2010. The trends for phototherapy, methotrexate (MTX), retinoids, cyclosporine A (CSA), systemic steroids, and biologics were all analyzed over the entire 18-year period and independently before and after the introduction of biologics in 2002.
RESULTS: From 1993 to 2010, the trend for total systemic treatments has not significantly increased (P=0.5). Frequency of phototherapy treatments significantly decreased from 1993 to 2010 (P<0.001). Since the introduction of biologics in 2002, their frequency has significantly increased, becoming the most frequently used treatment from 2008-2010 (P<0.0001).
LIMITATIONS: Severity of psoriasis was not recorded in the NAMCS and NHAMCS.
CONCLUSIONS: The frequency of systemic treatments to treat psoriasis has not significantly increased from 1993 to 2010. Despite the introduction of biologics, it appears that little progress has been made in reducing under-treatment of moderate-to-severe psoriasis.

J Drugs Dermatol. 2014;13(8):917-920.

INTRODUCTION

A 2004 study determined that the prevalence of diagnosed psoriasis was 3.15%, which is the equivalent of approximately 5 million adults, while the National Psoriasis Foundation estimates that the number may be as high as 7.5 million Americans.1,2 Psoriasis is more than an annoyance, and nearly 60% of those diagnosed with psoriasis report that their disease is a large problem in their daily life.3
Many individuals with moderate or severe psoriasis are not receiving any form of treatment or are undertreated. A 2007 study determined that 39% of patients categorized as having severe psoriasis and 37% of patients categorized as having moderate psoriasis were not receiving any form of treatment.4 Additionally, 35% of those who were diagnosed with moderate to severe psoriasis were treated with only topical treatments.4
With the introduction of biologics, safer systemic treatment options are available for patients with moderate-to-severe psoriasis, and these may be addressing past under-treatment of the disease. We sought to characterize the trends in systemic treatment for psoriasis over time.

METHODS

Data from annual surveys from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1993 through 2010 were analyzed. These surveys provide information on outpatient visits to non-federally employed outpatient physicians and the outpatient and emergency departments of short-stay hospitals, such as patient demographics, reasons provided by the patient for the visit, and any medications or therapies prescribed.
The rate of response to the NAMCS varied from 58.3% in 2010 to 73.0% in 1995 and 1993 over the 18-year period, with an average response rate of 65.6%, while the rate of response to the NHAMCS varied from 98.0% in 1998 to 89.4% in 2007 with an average response rate of 93.1%. Estimates produced were calculated with the weighting used by the NAMCS and NHAMCS to adjust for nonresponse to produce both national and unbiased estimates. All data analysis was performed using SAS 9.1.3 (SAS Institute, Cary, NC).
For the present study, visits with a diagnosis of psoriasis and no diagnosis of psoriatic arthritis were selected. Therapies analyzed included phototherapy, methotrexate (MTX), systemic retinoids, cyclosporine A (CSA), biologics, and systemic steroids. Phototherapy was identified by procedure code 99.82, 99.83, or a prescription for methoxsalen or psoralens. Retinoids included acitretin and etretinate, but topical retinoids were excluded. Systemic steroids included prednisone, methylprednisolone, and