Background: Zoledronic acid infusions are licensed for the treatment of osteoporosis and other bone disorders. Hypocalcaemia, a common side effect, increases the risk of complications. The risk of hypocalcaemia is further increased by a deficiency in 25-OH Vitamin D (VD). Pre-dose screening (PDS) is necessary to detect sub-optimal levels of serum VD and adjusted calcium (AC) early to avoid delayed treatment.
Objectives: Audit adherence to University Hospitals Birmingham (UHB) trust guidelines regarding:
1. The completion of PDS of serum VD and AC prior to administration of Zoledronic acid.
2. The appropriate management of adequate and sub-optimal serum VD results.
Methods: The study sample (n=51) was recruited from 284 patients. Included patients initiated Zoledronic acid in 2015, received two doses by December 2016, and failed to fulfil any exclusion criteria. The PDS results and management of these patients were recorded for both doses, highlighting 102 doses for analysis. Patient supplementation history was also recorded.
Findings: There was 100% adherence to the PDS standard. It was found that a greater proportion of patients had sub-optimal VD than AC levels (18.6% vs 0% respectively).
There was 98% adherence to the overarching management algorithm. Management of those with adequate VD levels showed greater adherence to guidelines compared to those with sub-optimal levels (100% vs 89.5% respectively).
Conclusions: The high adherence to PDS and management guidelines is a positive finding with only 2% of management decisions being off-protocol due to specialist decision.
Interestingly, seven patients with adequate VD levels on initial screening were found to have sub-optimal levels on PDS for the subsequent dose. This offers support for trust guidance to repeat PDS, however, there is scope to investigate this by cost-benefit analysis.
Additionally, 63% of patients with sub-optimal VD were supplemented, highlighting potential for further research into the efficacy of supplementation and patient compliance.