Intravenous bisphosphonates for post-menopausal osteoporosis: adherence to a network guideline

An evidence-based guideline on the use of intravenous (i.v.) bisphosphonates in post-menopausal osteoporosis was developed across a healthcare system and approved by clinical experts and Pharmacy and Therapeutics Committees. The objective of the study was to evaluate adherence to the guideline at hospitals in the healthcare system.

Post-menopausal women who received i.v. zoledronic acid or i.v. ibandronate for osteoporosis between September 2007 and October 2008 were identified through a data repository that provides patient-level longitudinal information on diagnoses, medications and laboratory tests. Manual review of electronic medical records supplemented the data capture. The guideline recommends use of i.v. bisphosphonates in patients: (i) who have had a recent vertebral or hip fracture; (ii) who cannot stand or sit upright for 30-60 min; (iii) who have oesophageal dysmotility or varices; (iv) who have documented adherence issues or, (v) who failed to tolerate oral bisphosphonates after 12 months. In addition, specific monitoring tests are recommended prior to administration.

Among the 220 women that received an i.v. bisphosphonate (hospitals A/B: n = 92 vs. hospital C: n = 128), 72% met the criteria for use. The results were similar when examined by institution (hospitals A/B 66% vs. hospital C 77%; P = 0·094). On review of the electronic medical records, an additional reason for using i.v. bisphosphonates was identified: persistent bone loss despite oral bisphosphonate therapy. When this criterion for use was included, the adherence rate increased to 80% (hospitals A/B 72% vs. hospital C 86%; P = 0·009). Serum calcium and 25-OH vitamin D were performed in 75% (hospitals A/B 77% vs. hospital C 73%; P = 0·53), and 86% (hospitals A/B 84% vs. hospital C 87%; P = 0·53) of patients respectively.

Adherence to an i.v. bisphosphonates evidence-based guideline was adequate (defined as at least 80%) although room for improvement in meeting the criteria for use at one hospital and for conducting baseline serum calcium levels was noted. A future project is warranted to re-assesses adherence after the measures to improve guideline adherence are implemented.