The cost-effectiveness of isotretinoin in the treatment of acne. Part 2. A chronic medication plan profiling study.

OBJECTIVES: Aspects of current clinical practice, needed for a pharmaco-economic model of isotretinoin, were determined from an acne-profiling study on chronic medication plan data. The patient sample was analysed as a whole and as two subgroups, representing isotretinoin and oral antibiotic patients. The study focused on the prevalence of the condition, patient age and gender distributions, and pharmacotherapeutic patterns and costs. METHODOLOGY: Anonymous patient records from the Pharmaceutical Benefit Management (Pty) Ltd, Cape Town, chronic medication plan were screened and analysed using descriptive and inferential statistical methods. For all hypothesis tests, the significance level (alpha) was set a priori at 5% (0.05). In order to determine the distribution of costs among patient groups, cost-concentration curves were constructed. RESULTS: A total of 5,198 patient records were analysed, representing 3,546 acne patients (2.7% of applicants to the plan). The majority of patients were female (72.2%, median age 23 years), with male patients treated at a younger age (median age 19 years). The cyproterone/oestrogen combination was found to be the most frequently prescribed agent (25.2% of script items), followed by isotretinoin (15.6%). The oral antibiotics as a group accounted for 24.9% of script items, the leading agents being minocycline (10.1%) and doxycycline (7.1%). Isotretinoin (44.1%) represented the greatest expense, followed by hormonal therapies (24.7%) and oral antibiotics (16.7%). Female isotretinoin patients (55.1%) were older (median age 25 years), while the male patients were of an equivalent age to the collective sample. Patients treated with oral antibiotics represented the youngest group of patients (median age 20 years), with 57.8% being female. The annual pharmacotherapy expense per patient on oral antibiotics was R1 971.81 compared with R2 670.20 for all patients, and R6 140.81 for the isotretinoin group. For each of these groups there was an uneven cost distribution among patients. CONCLUSION: The treatment of acne represents a significant burden to funders, estimated at R7.2 million per 100,000 beneficiaries. The distinct age and gender distribution patterns, together with the uneven distribution of costs among patients, provide valuable information for the treatment and management of the condition. This information indicates that the introduction of clinically based, focused management principles supported by sound pharmaco-economic arguments will be required to manage acne effectively.