The iatrogenic costs of NSAID therapy: a population study.

OBJECTIVE To estimate the iatrogenic costs of nonsteroidal antiinflammatory drug (NSAID) treatment from the perspective of the Italian National Health Service. METHODS We conducted a retrospective cohort study using the primary and secondary care claims data registered in the regional health service database in the Friuli-Venezia Giulia (Italy). The study cohort comprised all persons(265,114) who received at least one prescription for any NSAID between August 1996 and July 1998. The outcomes of interest were the costs of medical interventions for upper gastrointestinal disorders following NSAID treatment (i.e., prescriptions for gastroprotective drugs, hospitalizations, and outpatient diagnostic procedures). RESULTS The study population received a total of 660,311 NSAID prescriptions for a cost of 6,587,533 Euros (0.53 euro per treatment day). The cost of medical interventions for gastrointestinal events added 58% to the cost of NSAID therapy (0.31 euro per NSAID treatment day, up to 64% directly attributable to NSAID use). The iatrogenic costs were generated by 12.4% of the patients, 77% of whom had a positive history of gastrointestinal disorders and 82% of whom were older than 50 years. Co-prescriptions for gastroprotective drugs accounted for 78.6% of the overall iatrogenic costs. The iatrogenic costs did not differ between cyclooxygenase (COX) nonselective and COX-2 preferential drugs within strata of age and prior history of gastrointestinal disorders, but were significantly higher for the parenteral NSAIDs than the oral or rectal formulations. CONCLUSIONS In Italy, the iatrogenic costs of NSAID therapy add 58% to the cost of NSAID treatment; most of the cost is generated by co-prescriptions of gastroprotective drugs to elderly NSAID users or patients with a history of gastrointestinal disorders.