Increasing health care costs is an international problem from which SouthAfrica is not excluded. Prescription medication contributes most to these high health care costs,and methods to reduce their costs to society are implemented worldwide. In South Africa, sucha method is a managed care reference medicine price list, as introduced by a PBM (pharmacybenefit management) company. This step had some cost implications in the private healthsector in South Africa, and these implications were investigated in this study. Central nervoussystem (CNS) medicine items are among the top ten medicine items claimed and represent asubstantial amount of the costs of all medicine items claimed during the study period.Antidepressants, a subdivision of the CNS agents, comprise the largest share of CNS agentsclaimed and CNS costs, and were therefore investigated more closely.The objective of this study was to analyse the usage patterns and costs of centralnervous system medicine items, and more specifically, the antidepressants, against thebackground of the implementation of a managed care reference medicine price list in the privatesector of South Africa.This study was conducted as a retrospective, non-experimental quantitative researchproject. The study population consisted of all medicine items claimed as observed on thedatabase over the two-year study period of May 2001 to April 2002 (pre-MPL) and May 2002 toApril 2003 (post-MPL). Data were provided by MedschemeTM/lnterpharm, and the StatisticalAnalysis System® SAS 8.2® was used to extract the data from the database.The central nervous system agents had a prevalence of 8.10% (N=49098736) and atotal cost of R757576976.72 over the two-year study period. The cost per CNS item increasedby 5.98% or R11.50 per CNS item in the year after MPL implementation, and the cost perprescription containing CNS medicine items increased by 4.09% or R9.07 per prescription. CNSagents are classified into ten sub-pharmacological groups, according to the MIMSC3 (Snyman,2003:13a). One of these sub-pharmacological groups, antidepressants, comprised 33.97% of allCNS medicine items claimed (N=3978364) and 45.53% of all costs associated with CNSmedicine items (N=R757576976.72) over the study period. The number one antidepressantclaimed was amitriptyline, a tricyclic antidepressant. Of the antidepressants with genericsubstitutes, all with the exception of clomipramine, were prescribed at generic substitution ratesof more than 50%. After the MPL implementation, generic antidepressant products were morefrequently prescribed (16.48% increase, N=617190), although patient co-payments did notdecrease immediately. Some innovator products had price reductions after the implementationof the MPL.This study indicates that cost minimisation analyses and retrospective drug utilisation reviewsare valuable tools in the evaluation of managed care medicine price lists.
