[Calcitonin prescriptions: an estimate of the expenditure due to inadequate prescription].

Background: The use of calcitonin is very common in patients diagnosed with osteoporosis. The objective of this study was to determine the percentage of adequate prescriptions of calcitonin for patients with osteoporosis and to estimate the costs due to inadequate prescription.

Patients And Methods: Observational study. Four pharmacies in Osona County (Barcelona) were randomly selected. During two time periods, July-September and November-December of 1994, all women filling prescriptions for calcitonin in any of the eight pharmacies were invited to participate in the study. Adequate and inadequate prescription of calcitonin was determined based on the patient's clinical record. Justifiable and non-justifiable prescriptions were then determined after implementing a protocol and reviewing X-rays of the spine.

Results: Forty-eight women agreed to participate (participation rate: 68%). In the first analysis, 58.3% (95% CI: 43-72) of prescriptions were determined to be inadequate whereas in the second analysis 29.2% (95% CI: 17-44) were considered non-justifiable. Chronic back pain was associated with non-justifiable prescription of calcitonin (odds ratio: 5.2; 95% CI: 1.3-33.4). In the best of situations, the excess in annual spending due to inadequate prescription was estimated at 13 million pesetas for Osona County, 1,300 million for Catalonia, and 4,300 million for Spain.

Conclusions: Between one-third and one-half of patients prescribed calcitonin in the study area apparently do not need it. Many cases of chronic back pain are being treated as osteoporosis without being properly studied. The costs derived from this incorrect practice are important. This study highlights the need for better practices in the diagnosis of osteoporosis.