Background: Anti-inflammatory medications are the most common treatment for rheumatic disease in Australia. Recent years have seen large increases in the use of selective cyclooxygenase-2 (COX-2) inhibitors. Predictors of use, costs and benefits of the new medications have not been evaluated.
Aims: To determine trends in selective COX-2 inhibitor, non-steroidal anti-inflammatory drug (NSAID) and anti-ulcer medication (AUM) prescription following the introduction of selective COX-2 inhibitors; to determine predictors of selective COX-2 inhibitor, NSAID and AUM prescribing and to perform a limited evaluation of the costs and benefits associated with the introduction of selective COX-2 inhibitors.
Methods: Groups of consecutive patients attending a hospital rheumatology clinic, private rooms of consulting rheumatologists and a dermatology outpatient clinic were surveyed by investigator-administered questionnaire on three separate occasions. Information was sought about AUM, NSAID and selective COX-2 use and about factors likely to influence selective COX-2 prescribing. Sampling was carried out at 3, 10 and 16 months after the release of COX-2 selective inhibitors in Australia. The final survey was 3 months after Pharmaceutical Benefits Scheme (PBS) listing of celecoxib in Australia. Costs of treatment were calculated from survey findings of frequency of drug use as well as published drug prices and hospitalisation costs.
Results: Four-hundred and fifty-eight patients were surveyed. From the 3 months post-release to the 3 months post-PBS listing, a period of 13 months, COX-2 use in rheumatology patients increased from 18 to 57%. De novo prescription of selective COX-2 inhibitors increased from 42 to 61%. During the same period there was a fall in both NSAID (43-20%) and AUM use (41-27%). Neither selective COX-2 inhibitor nor NSAID prescription was related to risk factors for gastro-intestinal (GI) complications, but AUM use was found to correlate strongly to histories of gastroscopy, GI ulceration or GI bleed. The calculated increase in the cost of treatment was $1 033 002/10 000 patients per year. The net cost per serious GI event prevented was $71 736, compared with the normal cost of treatment of $2004.
Conclusions: Among rheumatology patients, selective COX-2 inhibitors have largely replaced NSAIDs and have resulted in a reduction in AUM consumption, but prescribing patterns for selective COX-2 inhibitors have not been related clearly to risk factors for GI complications. The introduction of selective COX-2 inhibitors has been associated with a significant increase in expenditure.