A randomised controlled trial of the clinical and cost-effectiveness of ultrasound-guided intra-articular corticosteroid and local anaesthetic injections: the hip injection trial (HIT) protocol

Abstract

Background

Evidence on the effectiveness of intra-articular corticosteroid injection for hip osteoarthritis is limited and conflicting. The primary objective of the Hip Injection Trial (HIT) is to compare pain intensity over 6 months, in people with hip OA between those receiving an ultrasound-guided intra-articular hip injection of corticosteroid with 1% lidocaine hydrochloride plus best current treatment with those receiving best current treatment alone. Secondary objectives are to determine specified comparative clinical and cost-effectiveness outcomes, and to explore, in a linked qualitative study, the lived experiences of patients with hip OA and experiences and impact of, ultrasound-guided intra-articular hip injection.

Methods

The HIT trial is a pragmatic, three-parallel group, single-blind, superiority, randomised controlled trial in patients with painful hip OA with a linked qualitative study. The current protocol is described, in addition to details and rationale for amendments since trial registration. 204 patients with moderate-to-severe hip OA will be recruited. Participants are randomised on an equal basis (1:1:1 ratio) to one of three interventions: (1) best current treatment, (2) best current treatment plus ultrasound-guided intra-articular hip injection of corticosteroid (triamcinolone acetonide 40 mg) with 1% lidocaine hydrochloride, or (3) best current treatment plus an ultrasound-guided intra-articular hip injection of 1% lidocaine hydrochloride alone. The primary endpoint is patient-reported hip pain intensity across 2 weeks, 2 months, 4 months and 6 months post-randomisation. Recruitment is over 29 months with a 6-month follow-up period. To address the primary objective, the analysis will compare participants’ ‘average’ follow-up pain NRS scores, based on a random effects linear repeated-measures model. Data on adverse events are collected and reported in accordance with national guidance and reviewed by external monitoring committees. Individual semi-structured interviews are being conducted with up to 30 trial participants across all three arms of the trial.

Discussion

To ensure healthcare services improve outcomes for patients, we need to ensure there is a robust and appropriate evidence-base to support clinical decision making. The HIT trial will answer important questions regarding the clinical and cost-effectiveness of intra-articular corticosteroid injections.

Trial registration

ISRCTN: 50550256, 28th July 2015.