Progressive exercise compared with best-practice advice, with or without corticosteroid injection, for rotator cuff disorders: the GRASP factorial RCT.

BACKGROUND: Rotator cuff-related shoulder pain is very common, but there is uncertainty regarding which modes of exercise delivery are optimal and the long-term benefits of corticosteroid injections.
OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of progressive exercise compared with best-practice physiotherapy advice, with or without corticosteroid injection, in adults with a rotator cuff disorder.
DESIGN: This was a pragmatic multicentre superiority randomised controlled trial (with a 2 × 2 factorial design).
SETTING: Twenty NHS primary care-based musculoskeletal and related physiotherapy services. PARTICIPANTS: Adults aged ≥ 18 years with a new episode of rotator cuff-related shoulder pain in the previous 6 months.
INTERVENTIONS: A total of 708 participants were randomised (March 2017-May 2019) by a centralised computer-generated 1 : 1 : 1 : 1 allocation ratio to one of four interventions: (1) progressive exercise (n = 174) (six or fewer physiotherapy sessions), (2) best-practice advice (n = 174) (one physiotherapy session), (3) corticosteroid injection then progressive exercise (n = 182) (six or fewer physiotherapy sessions) or (4) corticosteroid injection then best-practice advice (n = 178) (one physiotherapy session). MAIN OUTCOME MEASURES: The primary outcome was Shoulder Pain and Disability Index (SPADI) score over 12 months. Secondary outcomes included SPADI subdomains, the EuroQol 5 Dimensions, five-level version, sleep disturbance, fear avoidance, pain self-efficacy, return to activity, Global Impression of Treatment and health resource use. Outcomes were collected by postal questionnaires at 8 weeks and at 6 and 12 months. A within-trial economic evaluation was also conducted. The primary analysis was intention to treat.
RESULTS: Participants had a mean age of 55.5 (standard deviation 13.1) years and 49.3% were female. The mean baseline SPADI score was 54.1 (standard deviation 18.5). Follow-up rates were 91% at 8 weeks and 87% at 6 and 12 months. There was an overall improvement in SPADI score from baseline in each group over time. Over 12 months, there was no evidence of a difference in the SPADI scores between the progressive exercise intervention and the best-practice advice intervention in shoulder pain and function (adjusted mean difference between groups over 12 months -0.66, 99% confidence interval -4.52 to 3.20). There was also no difference in SPADI scores between the progressive exercise intervention and best-practice advice intervention when analysed at the 8-week and 6- and 12-month time points. Injection resulted in improvement in shoulder pain and function at 8 weeks compared with no injection (adjusted mean difference -5.64, 99% confidence interval -9.93 to -1.35), but not when analysed over 12 months (adjusted mean difference -1.11, 99% confidence interval -4.47 to 2.26), or at 6 and 12 months. There were no serious adverse events. In the base-case analysis, adding injection to best-practice advice gained 0.021 quality-adjusted life-years (p = 0.184) and increased the cost by £10 per participant (p = 0.747). Progressive exercise alone was £52 (p = 0.247) more expensive per participant than best-practice advice, and gained 0.019 QALYs (p = 0.220). At a ceiling ratio of £20,000 per quality-adjusted life-year, injection plus best-practice advice had a 54.93% probability of being the most cost-effective treatment. LIMITATIONS: Participants and physiotherapists were not blinded to group allocation. Twelve-month follow-up may be insufficient for identifying all safety concerns.
CONCLUSIONS: Progressive exercise was not superior to a best-practice advice session with a physiotherapist. Subacromial corticosteroid injection improved shoulder pain and function, but provided only modest short-term benefit. Best-practice advice in combination with corticosteroid injection was expected to be most cost-effective, although there was substantial uncertainty. FUTURE WORK: Longer-term follow-up, including any serious adverse effects of corticosteroid injection. TRIAL REGISTRATION: Current Controlled Trials ISRCTN16539266 and EudraCT 2016-002991-28. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 48. See the NIHR Journals Library website for further project information.