A microcosting analysis of zoledronic acid and pamidronate therapy in patients with metastatic bone disease

Our goal was to calculate resource use associated with administration of zo ledronic acid, compared with pamidronate, as palliative care for patients w ith metastatic bone lesions. We conducted a time-and-motion study of therap y administration at each of three outpatient chemotherapy infusion sites pa rticipating in clinical trials of zoledronic acid and pamidronate. We devel oped a data-collection instrument to record all staff effort and patient re source use in drug administration. The main outcome measures were (a) direc t costs of therapy administration per patient and (b) opportunity benefits expressed as the availability of resources gained per year. The average vis it time for patients receiving the study dose of zoledronic acid, 4 mg, was 1 h, 6 min, compared to 2 h, 52 min for patients receiving a 90-mg dose of pamidronate. Infusion time accounted for much of the difference. In the ba se-case analysis, total direct costs per patient were $728 for zoledronic a cid and $776 for pamidronate. The opportunity benefit for infusion of zoled ronic acid vs pamidronate in the base case was 1.8 chairs per day, or 426 c hairs per 240-workday year. Results were sensitive to changes in infusion f acility size, days of operation, and average number of patients treated. Sh orter infusion time associated with the administration of zoledronic acid, compared with pamidronate, yields substantial time savings for patients, as well as opportunity benefits for outpatient oncology facilities.