Can EQ-5D-3L utility values of low back pain patients be validly predicted by the Oswestry Disability Index for use in cost-effectiveness analyses?

Appropriateness and Quality of Composite Endpoint Use and Reporting in Spine Surgery: A Systematic Review

BACKGROUND

A composite endpoint (CEP) is a measure comprising 2 or more separate component outcomes. The use of these constructs is increasing. We sought to conduct a systematic review on the usage, quality of reporting, and appropriate use of CEPs in spine surgery research.

METHODS

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Articles reporting randomized controlled trials of a spine surgery intervention using a CEP as a primary outcome were included. We assessed the quality of CEP reporting, appropriateness of CEP use, and correspondence between CEP treatment effect and component outcome treatment effect in the included trials.

RESULTS

Of 2,321 initial titles, 43 citations were included for analysis, which reported on 20 unique trials. All trials reported the CEP construct well. In 85% of trials, the CEP design was driven by US Food and Drug Administration guidance. In the majority of trials, the reporting of CEP results did not adhere to published recommendations: 43% of tests that reported statistically significant results on component outcomes were not statistically significant when adjusted for multiple testing. 67% of trials did not meet appropriateness criteria for CEP use. In addition, CEP treatment effect tended to be 6% higher than the median treatment effect for component outcomes.

CONCLUSION

Given that CEP analysis was not appropriate for the majority of spine surgery trials and the inherent challenges in the reporting and interpretation of CEP analysis, CEP use should not be mandated by regulatory bodies in spine surgery trials.

LEVEL OF EVIDENCE

Level I. See Instructions for Authors for a complete description of levels of evidence.

Mapping Oswestry Disability Index Responses to EQ-5D-3L Utility Values: Are Cost-Utility Results Valid?

OBJECTIVES

To develop and validate approaches for mapping Oswestry Disability Index responses to 3-level version of EQ-5D utility values and to evaluate the impact of using mapped utility values on cost-utility results compared with published regression models.

METHODS

Three response mapping approaches were developed in a random sample of 70% of 18 692 patients with low back pain: nonparametric approach (Non-p), nonparametric approach excluding logical inconsistencies (Non-peLI), and ordinal logistic regression (OLR). Performance was assessed in the remaining 30% using R-square (R²), root mean square error (RMSE), and mean absolute error (MAE). To evaluate whether MAEs and their 95% limits of agreement (LA) were clinically relevant, a minimally clinically important difference of 0.074 was used. Probabilities of cost-effectiveness estimated using observed and mapped utility values were compared in 2 economic evaluations.

RESULTS

The Non-p performed the best (R² = 0.43; RMSE = 0.22; MAE = 0.03; 95% LA = -0.40 to 0.47) compared with the Non-peLI (R² = 0.07; RMSE = 0.29; MAE = -0.15; 95% LA = -0.63 to 0.34) and OLR (R² = 0.22; RMSE = 0.26; MAE = 0.02; 95% LA = -0.49 to 0.53). MAEs were lower than the minimally clinically important difference for the Non-p and OLR but not for the Non-peLI. Differences in probabilities of cost-effectiveness ranged from 1% to 4% (Non-p), 0.1% to 9% (Non-peLI), and 0.1% to 20% (OLR).

CONCLUSIONS

Results suggest that the developed response mapping approaches are not valid for estimating individual patients' 3-level version of EQ-5D utility values, and-depending on the approach-may considerably affect cost-utility results. The developed approaches did not perform better than previously published regression-based models and are therefore not recommended for use in economic evaluations.

Effect of different weekly frequencies of Chen-style Tai Chi in elders with chronic non-specific low back pain: study protocol for a randomised controlled trial

BACKGROUND

Tai Chi (TC), as one of mild to moderate exercise therapies specifically recommended by clinical practice guideline from the American College of Physician, is a viable option for chronic non-specific low back pain (CNLBP) treatment. Nevertheless, limited studies focused on the effect of different weekly frequencies of TC in elders with CNLBP. This superiority study aims to compare the differences of TC with different weekly frequencies in elders with CNLBP on the premise of proving its effectiveness, and identifying whether mindfulness mediates the effect of TC on treatment outcomes.

METHODS

In total, 284 senior citizens with CNLBP will be recruited in this single-centre, randomised, single-blinded (outcome assessors, data managers and the statistician), parallel controlled trial. Participants will be randomly divided into either one of three TC groups (1, 3, or 5 sessions/week, on the basis of weekly health educational lectures) or weekly health educational lectures, sustaining for 12 weeks, followed by 12 weeks of follow-up after the end of intervention. The primary outcome (the changes of LBP intensity at rest) will be measured at baseline before randomisation and immediately after the completion of weeks 4, 8 and 12 of the intervention, and the end of follow-up (week 24) using the visual analogue scale (VAS, 0-10 cm) to put a mark on the VAS scale to show how severities of their average low back pain have been over the past 24 h. Secondary outcomes, including Beck Depression Inventory-II, Pain Catastrophising Scale and Five Facet Mindfulness Questionnaire, Oswestry Disability Index and Short Form-36, will be measured at baseline and immediately after the completion of week 12 of the intervention and end of follow-up. The intention-to-treat and per-protocol principles will be used to analyse outcomes with a setting at α = 0.05 as statistical significance.

DISCUSSION

This comprehensive and detailed protocol will be the first trial to compare the effectiveness of different weekly frequencies of TC in elders with CNLBP. The outcomes may provide valuable data about the choice of the ideal number of sessions to further normalise the application of exercise for clinicians.

TRIAL REGISTRATION

Chinese clinical trial registry ChiCTR2200058190 . Registered on 1 April 2022.