Connecting real-world digital mobility assessment to clinical outcomes for regulatory and clinical endorsement-the Mobilise-D study protocol.

BACKGROUND: The development of optimal strategies to treat impaired mobility related to ageing and chronic disease requires better ways to detect and measure it. Digital health technology, including body worn sensors, has the potential to directly and accurately capture real-world mobility. Mobilise-D consists of 34 partners from 13 countries who are working together to jointly develop and implement a digital mobility assessment solution to demonstrate that real-world digital mobility outcomes have the potential to provide a better, safer, and quicker way to assess, monitor, and predict the efficacy of new interventions on impaired mobility. The overarching objective of the study is to establish the clinical validity of digital outcomes in patient populations impacted by mobility challenges, and to support engagement with regulatory and health technology agencies towards acceptance of digital mobility assessment in regulatory and health technology assessment decisions. METHODS/DESIGN: The Mobilise-D clinical validation study is a longitudinal observational cohort study that will recruit 2400 participants from four clinical cohorts. The populations of the Innovative Medicine Initiative-Joint Undertaking represent neurodegenerative conditions (Parkinson's Disease), respiratory disease (Chronic Obstructive Pulmonary Disease), neuro-inflammatory disorder (Multiple Sclerosis), fall-related injuries, osteoporosis, sarcopenia, and frailty (Proximal Femoral Fracture). In total, 17 clinical sites in ten countries will recruit participants who will be evaluated every six months over a period of two years. A wide range of core and cohort specific outcome measures will be collected, spanning patient-reported, observer-reported, and clinician-reported outcomes as well as performance-based outcomes (physical measures and cognitive/mental measures). Daily-living mobility and physical capacity will be assessed directly using a wearable device. These four clinical cohorts were chosen to obtain generalizable clinical findings, including diverse clinical, cultural, geographical, and age representation. The disease cohorts include a broad and heterogeneous range of subject characteristics with varying chronic care needs, and represent different trajectories of mobility disability. DISCUSSION: The results of Mobilise-D will provide longitudinal data on the use of digital mobility outcomes to identify, stratify, and monitor disability. This will support the development of widespread, cost-effective access to optimal clinical mobility management through personalised healthcare. Further, Mobilise-D will provide evidence-based, direct measures which can be endorsed by regulatory agencies and health technology assessment bodies to quantify the impact of disease-modifying interventions on mobility. TRIAL REGISTRATION: ISRCTN12051706.

Comparing cost-effectiveness of X-Stop with minimally invasive decompression in lumbar spinal stenosis: a randomized controlled trial.

STUDY DESIGN: Randomized clinical trial with 2-year follow-up. OBJECTIVE: To compare the cost-effectiveness of X-stop to minimally invasive decompression in patients with symptomatic lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Although surgery is more costly than nonoperative treatment, health outcomes for more than 2 years were shown to be significantly better. Surgical treatment with minimally invasive decompression is widely used. X-stop is introduced as another minimally invasive technique showing good results compared with nonoperative treatment. METHODS: We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either minimally invasive decompression or X-stop. Quality-adjusted life-years were based on EuroQol EQ-5D. The hospital unit costs were estimated by means of the top-down approach. Each cost unit was converted into a monetary value by dividing the overall cost by the amount of cost units produced. The analysis of costs and health outcomes is presented by the incremental cost-effectiveness ratio. RESULTS: The study was terminated after a midway interim analysis because of significantly higher reoperation rate in the X-stop group (33%). The incremental cost for X-stop compared with minimally invasive decompression was &OV0556;2832 (95% confidence interval: 1886-3778), whereas the incremental health gain was 0.11 quality-adjusted life-year (95% confidence interval: -0.01 to 0.23). Based on the incremental cost and effect, the incremental cost-effectiveness ratio was &OV0556;25,700. CONCLUSION: The majority of the bootstrap samples displayed in the northeast corner of the cost-effectiveness plane, giving a 50% likelihood that X-stop is cost-effective at the extra cost of &OV0556;25,700 (incremental cost-effectiveness ratio) for a quality-adjusted life-year. The significantly higher cost of X-stop is mainly due to implant cost and the significantly higher reoperation rate. LEVEL OF EVIDENCE: 2.

MRI evaluation of lumbar spinal stenosis: is a rapid visual assessment as good as area measurement?

BACKGROUND: Lumbar spinal stenosis (LSS) is commonly assessed on MRI by measuring dural sac cross-sectional area (DSCA). A new method, morphological grading A-D, has recently been introduced as an alternative method. OBJECTIVE: The aim of this study is to compare these two different methods for assessing LSS on MRI and study their reliability and intercorrelation. METHODS: On pretreatment MRI of 84 patients, two experienced radiologists independently classified level L2/L3, L3/L4 and L4/L5 as no, relative or significant stenosis using both methods. Agreement was analyzed by weighted Kappa. The correlation between the two methods was analysed using Spearman correlation, and visualized in a box plot. RESULTS: The interobserver agreement (95 % CI) was 0.69 (0.61-0.77) and 0.65 (0.56-0.74), respectively. The intraobserver agreements for DSCA were 0.77 (0.60-0.74) and 0.80 (0.66-0.93). On morphological grading A-D it was 0.78 (0.65-0.92) and 0.81 (0.68-0.94). The correlation coefficient between the two methods was 0.85 (p < 0.001). Grades C and D were under the limit value for significant stenosis using the DSCA. CONCLUSIONS: The study shows that the inter- and intraobserver agreements of DSCA and morphological grading A-D were acceptable and their intercorrelation is strong. Both methods may be used in the MRI evaluation of LSS.

Cost-effectiveness of total disc replacement versus multidisciplinary rehabilitation in patients with chronic low back pain: a Norwegian multicenter RCT.

STUDY DESIGN: Randomized clinical trial with 2-year follow-up. OBJECTIVE: To evaluate the cost-effectiveness of total disc replacement (TDR) versus multidisciplinary rehabilitation (MDR) in patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: The existing studies on CLBP report cost-effectiveness of fusion surgery versus disc replacement and fusion versus rehabilitation. This study evaluated the cost-effectiveness of TDR versus MDR. METHODS: Between April 2004 and May 2007, 173 patients with CLBP (>1 yr) were randomized to TDR (n = 86) or MDR (n = 87). Treatment effects (Euro Qol 5D [EQ-5D] and Short Form 6D [SF-6D]) and relevant direct and indirect costs at 6 weeks and at 3, 6, 12, and 24 months after treatment were assessed. Gain in quality-adjusted life years (QALYs) after 2 years was estimated. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio. RESULTS: The mean QALYs gained (standard deviation) using EQ-5D was 1.29 (0.53) in the TDR group and 0.95 (0.52) in the MDR group, a significant difference of 0.34 (95% confidence interval 0.18-0.50). The mean total cost per patient in the TDR group was &OV0556;87,622 (58,351) compared with &OV0556;74,116 (58,237) in the MDR group, which was not significantly different (95% confidence interval: -4041 to 31,755). The incremental cost-effectiveness ratio for the TDR procedure varied from &OV0556;39,748 using EQ-5D (TDR cost-effective) to &OV0556;128,328 using SF-6D (TDR not cost-effective). The dropout rate was 20% (15% TDR group, 24% MDR group). Five patients moved from the MDR to the TDR group, whereas 9 patients randomized to TDR declined surgery. Using per-protocol analysis instead of intention-to-treat analysis indicated that TDR was not cost-effective, irrespective of the use of EQ-5D or SF-6D. CONCLUSION: In this study, TDR was cost-effective compared with MDR after 2 years when using EQ-5D for assessing QALYs gained and a willingness to pay of &OV0556;74,600 (kr500,000/QALY). TDR was not cost-effective when SF-6D was used; therefore, our results should be interpreted with caution. Longer follow-up is needed to accurately assess the cost-effectiveness of TDR. LEVEL OF EVIDENCE: 2.