Risk-benefit and costs of unicompartmental (compared to total) knee replacement for patients with multiple co-morbidities: a non-randomised study, and different novel approaches to minimize confounding (UTMOST)

Study identification

• EU PAS number:
  EUPAS17435
• Study ID:
  28022
• Official title and acronym:
  Risk-benefit and costs of unicompartmental (compared to total) knee replacement for patients with multiple co-morbidities: a non-randomised study, and different novel approaches to minimize confounding (UTMOST)
• DARWIN EU® study:
  No
• Study countries:
  United Kingdom
• Study description:
  Although a RCT (TOPKAT) is ongoing to compare unicompartemental (UKR) and total knee replacement (TKR), limited follow-up and restrictive eligibility criteria will limit external validity to a large number of patients with multiple co-morbidities. Our aims are:1.-To validate a number of analytical methods to minimise confounding: we will replicate TOPKAT by analysing the association between UKR (compared to TKR) and post-operative patient reported outcomes (PROMs) amongst participants in the National Joint Registry for England and Wales(NJR) eligible for TOPKAT (ASA grade <3) using different methods, and then test for a difference between the obtained estimates and TOPKAT.-To study the benefits (PROMs), risks (revision, complications), mortality, costs and cost-effectiveness of UKR (vs TKR) amongst NJR participants not eligible for TOPKAT. Methods previously validated will be applied for this second Aim.We will conduct a cohort analysis using routinely collected data from the NJR linked to hospital admission records (HES) and the National PROMs Database.-Primary outcome: post-operative Oxford Knee Score (PROMs).-Secondary outcomes: one and 5-year risks (revision surgery, systemic infection, wound infection, cardiovascular disease, and venous thromboembolism), mortality, health-related quality of life (EQ-5D), hospital costs (as in HES).-Power: Based on published data, >720 UKR and 8,400 TKR recipients in the co-morbidity cohort will have linked PROMs. With an expected standard deviation of 8, power will be 90% to detect a minimally clinically important difference of 2+ points in Oxford Knee Score.-Statistics: Linear regression will be used to study the association between surgery (UKR vs TKR) and post-operative PROMs. Survival models will be fitted to study time-to-event (one model for each of the proposed secondary outcomes) according to UKR/TKR. Generalized linear models (GLMs) will be used to study costs and their relationship with surgery type.
• Study status:
  Ongoing

Research institutions and networks

Institutions

Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford

United Kingdom

Centre for Statistics in Medicine

Study timelines

Date when funding contract was signed

Planned:31/03/2017

Actual:12/01/2017

Study start date

Planned:02/10/2017

Actual:09/12/2017

Data analysis start date

Planned:02/04/2018

Actual:01/10/2018

Date of final study report

Planned:28/06/2019

Sources of funding

Other

More details on funding

NIHR HTA, University of Oxford

Regulatory

• Was the study required by a regulatory body?:
  No
• Is the study required by a Risk Management Plan (RMP)?:
  Not applicable