Background. The majority of studies assessing minimal clinical important difference in outcome do so for management of chronic low back pain. Those that identify MCID following spinal surgical intervention fail to differentiate between the different pathologies and treatments or use variable methods and anchors in the calculation. Aim. To identify the MCID in scores across the most common spinal surgical procedures using standardised methods of calculation. Method. Prospective longitudinal study following elective lumbar spinal surgery. All patients had a complete set of spinal outcome assessments (ODI and VAS) and self perceived rating of the global and Mcnab criteria. MCID was calculated as defined by Hagg et al. Results. 244 patients of average age 53 years were followed up for 62 months post surgery. The MCID across the range of spinal surgeries was a 10 point change in ODI and 28 points for the VAS. A MCID following lumbar decompression surgery was a 3 point change in ODI and 29 points for VAS; 24 points in ODI and 37 points in the VAS for a discectomy, and 13 points in ODI and 23 point change in VAS for revision surgery. This value also varied depending on the anchor and method used for calculation. Conclusion. The MCID in score varies between different spinal procedures, method of calculation and the external anchor used. Standardised methods of calculating MCID in outcome measures should be used to allow comparative research and assessment. Generalisation of MCID in scores across a range of spinal procedures should be strongly discouraged. Conflicts of Interest. None. Source of Funding. None. This abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting

Objectives. We aimed first to summarise minimal clinically important differences (MCIDs) after total hip (THR) or knee replacement (TKR) in health-related quality of life (HRQoL), measured using the Short-Form 36 (SF-36). Secondly, we aimed to improve the precision of MCID estimates by means of meta-analysis. Methods. We conducted a systematic review of English and non-English articles using MEDLINE, the Cochrane Controlled Trials Register (1960–2011), EMBASE (1991–2011), Web of Science, Academic Search Premier and Science Direct. Bibliographies of included studies were searched in order to find additional studies. Search terms included MCID or minimal clinically important change, THR or TKR and Short-Form 36. We included longitudinal studies that estimated MCID of SF-36 after THR or TKR. Results. Three studies met our inclusion criteria, describing a distinct study population: primary THR, primary TKR and revision THR. No synthesis of study results can be given. Conclusions. Although we found MCIDs in HRQoL after THR or TKR have limited precision and are not validated using external criteria, these are still the best known estimates of MCIDs in HRQoL after THR and TKR to date. We therefore advise these MCIDs to be used as absolute thresholds, but with caution

Background. This article reviews four commonly used approaches to assess patient responsiveness to a treatment or therapy [Return To Normal (RTN), Minimal Important Difference (MID), Minimal Clinically Important Difference (MCID), OMERACT-OARSI (OO)], and demonstrates how each of the methods can be formulated in a multi-level modelling (MLM) framework. Methods. Data from the Arthroplasty Pain Experience (APEX) cohort study was used. Patients undergoing total hip and knee replacement completed the Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire prior to surgery and then at 3, 6 and 12 months after surgery. We compare baseline scores, change scores, and proportion of individuals defined as “responders” using traditional and multi-level model (MLM) approaches to patient responsiveness. Results. Using existing approaches, baseline and change scores are underestimated, and the variance of baseline and change scores overestimated in comparison to MLM approaches. MLM increases the proportion of individuals defined as responding in RTN, MID, and OO criteria compared to existing approaches. Using MLM with the MCID criteria reduces the number of individuals identified as responders. Conclusion. MLM improves the estimation of the standard deviation of baseline and change scores by explicitly incorporating measurement error into the model, and avoiding regression to the mean when making individual predictions. Using refined definitions of responsiveness may lead to a reduction in misclassification when attempting to predict who does and does not respond to an intervention, and clarifies the similarities between existing methods. Approvals. The APEX trials were registered as an International Standardised Randomised Controlled Trial (96095682), approved by Southampton and South West Hampshire Research Ethics Committee (09/H0504/94) and all participants provided informed written consent

Objectives

To define Patient Acceptable Symptom State (PASS) thresholds for the Oxford hip score (OHS) and Oxford knee score (OKS) at mid-term follow-up.