Application of the findings of the European Stroke Prevention Study 2 (ESPS-2) to a New Zealand ischaemic stroke cost analysis.

Abstract

The aim of this study was to apply the findings of the European Stroke Prevention Study 2 (ESPS-2) to a paper that quantified and described the annual cost of ischaemic stroke in New Zealand, and to compare the cost of alternative drug regimens in the secondary prevention of ischaemic stroke. Comparisons were made between the costs of low-dosage aspirin (acetylsalicylic acid) monotherapy and a combination of modified-release dipyridamole and low-dosage aspirin. Differences in undiscounted costs were calculated over a 2-year period. The New Zealand cost per stroke event was multiplied by the ESPS-2 incremental reduction in stroke events to derive the cost of strokes avoided. As the focus of the paper was on direct medical costs, the primary perspective adopted was that of a healthcare provider or funder, but a societal perspective was also considered by evaluation of direct nonmedical and indirect costs. Compared with aspirin monotherapy, combination therapy generated incremental net direct costs of 18.22 New Zealand dollars ($NZ) per patient or $NZ18,223 per 1000 patients. However, individually, each treatment regimen resulted in direct cost savings when compared with placebo: combination therapy $NZ905.16 per patient; aspirin monotherapy $NZ923.39 per patient (a difference between the 2 regimens of $NZ18.22 per patient). Total direct and indirect incremental cost savings were $NZ40.96 per patient, and $NZ40,963 per 1000 patients, for the combination therapy. The analysis demonstrates that changing patients from low-dosage aspirin to a combination therapy of modified-release dipyridamole plus low-dosage aspirin would result in a small rise in incremental direct costs (using our conservative assumptions relating to hospital and continuing institutional care costs). If less conservative unit cost assumptions were adopted, a more likely outcome would be a saving in direct incremental costs of up to $NZ400 per patient treated.