Hospital-, anaesthetist-, and patient-level variation in peripheral nerve block utilisation for hip fracture surgery: a population-based cross-sectional study

Background — Unwarranted variation in anaesthesia practice is associated with adverse outcomes. Despite high-certainty evidence of benefit, a minority of hip fracture surgery patients receive a peripheral nerve block. Our objective was to estimate variation in peripheral nerve block use at the hospital, anaesthetist, and patient levels, while identifying predictors of peripheral nerve block use in hip fracture patients.

Methods — After protocol registration (https://osf.io/48bvp/), we conducted a population-based cross-sectional study using linked administrative data in Ontario, Canada. We included adults >65 yr of age having emergency hip fracture surgery from April 1, 2012 to March 31, 2018. Logistic mixed models were used to estimate the variation in peripheral nerve block use attributable to hospital-, anaesthetist-, and patient-level factors with use of peripheral nerve block, quantified using the variance partition coefficient and median odds ratio. Predictors of peripheral nerve block use were estimated and temporally validated.

Results — Of 50 950 patients, 9144 (18.5%) received a peripheral nerve block within 1 day of surgery. Patient-level factors accounted for 14% of variation, whereas 42% and 44% were attributable to the hospital and anaesthetist providing care, respectively. The median odds ratio for receiving a peripheral nerve block was 5.73 at the hospital level and 5.97 at the anaesthetist level. No patient factors had large associations with receipt of a peripheral nerve block (odds ratios significant at the 5% level ranged from 0.86 to 1.35).

Conclusions — Patient factors explain the minimal variation in peripheral nerve block use for hip fracture surgery. Interventions to increase uptake of peripheral nerve blocks for hip fracture patients will likely need to focus on structures and processes at the hospital and anaesthetist levels.