Title: A randomised controlled trial of patient directed self management of pain (PaDSMaP) compared to treatment as usual following total knee replacement
Funder: Department of Health (England)

Abstract: Background Over the last 4 years the numbers of primary total knee replacements (TKR) operations have increased by 163% to 73,455 in England and Wales, and are expected to continue increasing due to the ageing demographic of the UK population and increasing confidence of a good outcome from the surgery by surgeons and patients. However patients experienced substantial pain post-operatively which can reduce the time taken for patients to mobilise and return to normal activities and may predispose patients to develop chronic pain and adverse events. A patient’s level of pain and satisfaction with care may be influenced by who delivers pain control medications i.e. whether it is patient-directed self management of pain (PaDSMaP) or under nurse control (treatment as usual, TAU). Aims This pragmatic randomised controlled trial (RCT) will evaluate the efficacy and cost-effectiveness of patient-directed self management of pain (PaDSMaP) compared to nurse-controlled analgesia (TAU) in patients who have undergone a primary TKR. The primary outcome will be to compare the patient’s levels of pain at three days after a primary TKR operation in the 2 groups. It will also compare the two groups up to 6 weeks post-operatively with respect to satisfaction with pain control, quality of life (QOL), activities of daily living (ADL), adverse effects and time to mobilisation. Further, it will determine the acceptability of PaDSMaP to patients and the multidisciplinary surgical and ward teams Finally it will determine the interventions’ relative costs and cost effectiveness. Plan of Investigation A prospective, randomised, parallel-group, single blinded, active-control study of PaDSMaP (patient-directed self management of pain) compared to TAU (nurse-controlled analgesia) for patients undergoing a primary unilateral TKR at a district general teaching hospital the Norfolk and Norwich University Hospital Foundation Trust (N&NUHFT). The data analysis will be blinded. A sample of 72 patients per arm is sufficient to detect a between-group difference of 0.5 standard deviations (approximately 12 points) in the primary outcome measure, a 0-100 visual analogue scale pain score at three days after a primary TKR operation, with 80% power and allowing for 10% drop out. Secondary outcomes will include satisfaction with pain control, QOL, ADL, adverse effects, time to mobilisation, and costs. Potential Impact It is hoped that the results of this study will allow the NHS to improve post-operative pain control after TKR. Hopefully it will also improve patient’s satisfaction with their pain control, reduce time to mobilisation, and reduce the incidence of adverse events. It is likely that the information from this study will be relevant to post-operative analgesic care in general for all patients capable of managing oral analgesics. In addition to the funds requested here the patients entered into this study will form a cohort that will be audited for up to 5 years to determine the impact of pre-operative characteristics (anxiety, depression, pain levels) and post-operative pain control on the long-term success or failure of TKRs as defined by the development of chronic pain, ADL and QOL.


Research activity codes: 7.1 INDIVIDUAL CARE NEEDS
Health categories: MUSCULOSKELETAL