Usage patterns and cost analysis of angiotensin-converting enzyme (ACE) inhibitors using a medical aid claims database
Abstract
ACE inhibitors have been widely used in the treatment of certain diseases of the
cardiovascular system, the major use being hypertension, since all ACE inhibitors are prescribed for its treatment. ACE inhibitors is also used in the treatment of congestive heart failure.
The angiotensin-converting enzyme (ACE) converts angiotensin 1 into angiotensin 11 and also stimulates the production of aldosterone (a hormone produced in the adrenal glands that influences salt and water retention by the kidneys, increasing blood volume and blood pressure). The cost benefit, cost-effectiveness and cost utility of ACE inhibitors have not been
established. The objective of the study was to review and analyse the cost of ACE
inhibitors by using a medical aid claims database. Data for the study population consisted of all prescriptions containing one or more ACE inhibitor combinations and were extracted from the central database of Interpharm datasystems for a period of one year, from 1 January 2001 to 31 December 2001. A total of 1 475 532 prescriptions containing a total of 2 953 244 ACE inhibitor items represented the study population. Through the analysis of the general medicine utilisation patterns that were obtained from the medicine claims database, it became evident that ACE inhibitor utilisation contributes considerably to the total prevalence and cost of all the medicine items available on the database. It constituted a total prevalence of 4,62% (n =1 475 532) of
all the prescriptions and a total prevalence of 2,31% (n =2 953 244) for all the medicine items in the prescriptions with a cost of 3,65% (n =R379 91 1 472,00).
It was concluded that in the analysis of ACE inhibitors according to the
innovator/generic classification, the majority of ACE inhibitors prescribed during the twelve-month period were for the innovator product, with a prevalence of 82,56% (n=68 162) and a cost of 89,11% (n =R13 863 080, 90). The utilisation of the generic ACE inhibitors, with a prevalence of 17,44% (n =68 162) and at a cost of 10,89% (n=R13 863 080, 90), was under-utilised. If the total number of prescriptions containing innovator ACE inhibitors could be generically substituted, (37,54%) R5 204 392,68 in
cost expenditure could be saved over a twelve-month period. However, the fact that not all the innovator ACE inhibitors have generic equivalents available must be taken into account. If only the prescriptions containing ACE inhibitor items that have generic equivalents were to be substituted with their generic equivalents, R899 751.29(6.5%) would be saved. This was found by adding all the costs saved by substituting innovator drugs with their generics. Consequently, it can be concluded that the extensive use of the innovator ACE inhibitors could mean an exceptional increase in the cost expenditure associated with ACE inhibitor therapy. In completion of the study, recommendations were formulated as an aim to optimise the utilisation of ACE inhibitor generic equivalents.
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- Health Sciences [2061]