Administrative claims analysis of utilization and costs of care in health plan members with atopic dermatitis who had prior use of a topical corticosteroid and who initiate therapy with pimecrolimus or tacrolimus

BACKGROUND: In the United States, pimecrolimus cream and tacrolimus ointment are approved as second-line therapy for short-term and intermittent noncontinuous long-term treatment of atopic dermatitis (AD) in nonimmuno-compromised patients aged 2 years or older who have failed to respond adequately to other topical prescription treatments (e.g., topical corticosteroids), or when those treatments are not advisable; pimecrolimus is indicated for mild-to-moderate AD and tacrolimus for moderate-to-severe AD. Comparative data on the effects of pimecrolimus versus tacrolimus on AD-related health care utilization and costs among similar patients seen in typical clinical practice are currently unavailable. OBJECTIVE: To compare utilization and costs of AD-related medical care in health plan members with AD who had prior use of a topical corticosteroid and who subsequently initiate therapy with pimecrolimus cream or tacrolimus ointment. METHODS: This was an observational, retrospective study using an administrative claims database with dates of service from August 1, 2000, through October 31, 2003, and representing approximately 2.5 million members in health maintenance organizations, preferred provider organizations, and Medicare and Medicaid plans mostly located in the cities of Chicago, Kansas City, and Phoenix and in the states of Kentucky, Florida, and Texas. The study sample included all members with I or more pharmacy claims for a topical corticosteroid and a diagnosis of AD (international Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 691.XX (excluding 691.OX), or 692.XX (excluding 692.0X-692.8X)] who subsequently had 1 or more pharmacy claims for pimecrolimus or tacrolimus. AD-related utilization and medical care costs (plan payments plus member cost share) over 12 months of follow-up were compared between the pimecrolimus and tacrolimus groups. Because information on disease severity was not available in the administrative claims data, propensity matching was used to control for differences between groups in baseline demographic and clinical characteristics and pretreatment utilization of AD-related medical care services. RESULTS: Before matching, compared with the tacrolimus group (n = 197), members in the pimecrolimus group (n = 197) were older (mean age of 38 vs. 32 years, P= 0.022), had fewer topical corticosteroid pharmacy claims (mean 2.08 vs. 3.01, P= 0.002), and had fewer grams of corticosteroids dispensed (mean 132 vs. 193, P= 0.029) in the 12 months prior to treatment. After matching, there were 157 members in each group with no statistically significant differences in pretreatment characteristics. During the 12-month follow-up period, the mean (median) number of pharmacy claims was 1.8 (1.0) for pimecrolimus versus 2.0 (1.0) for tacrolimus and the mean (median) grams of study medication were 102 (60) and 105 (60), respectively. Members in the pimecrolimus group received a lower average number of prescriptions for any topical corticosteroids (1.37 vs. 2.04, P= 0.021) and for high-potency topical corticosteroids (0.61 vs. 1.04, P= 0.023) and were less likely to initiate alternative therapy (5% vs. 17%, P < 0.001) or receive antistaphylococcal antibiotics (16% vs. 27%, P=0.014). Members in the pimecrolimus group had lower average (median) AD-related expenditures (75% to 78% attributable to AD drug cost) compared with matched tacrolimus members ($263 [$270] vs. $361 [$398], P= 0.012). CONCLUSIONS: In health plan members with AD who had previously received at least 1 topical corticosteroid prescription, the customary use of pimecrolimus or tacrolimus was 1 to 2 prescriptions in 12 months of follow-up and only a median of 60 grams of topical medication. The difference in AD-related utilization and costs between pimecrolimus and tacrolimus was small, less than $100 per year, but favored pimecrolimus. Further research using validated measures of disease severity to control for potential confounding is needed to confirm the results of this observational study.