Maislin Greg, Keenan Brendan T, Alamin Todd F, Fielding Louis C, Scherman Ashley, Hachadoorian Robert, Pierre Clifford, Sasso Rick C, Lavelle William F, Chapman Jens
Biomedical Statistical Consulting LLC®, Philadelphia, PA, USA.
Department of Orthopaedic Sugery, Stanford School of Medicine, Redwood City, CA, USA.
Global Spine J. 2025 Jan 27:21925682251316287. doi: 10.1177/21925682251316287.
Prospective Observational Propensity Score.
Randomization may lead to bias when the treatment is unblinded and there is a strong patient preference for treatment arms (such as in spinal device trials). This report describes the rationale and methods utilized to develop a propensity score (PS) model for an investigational device exemption (IDE) trial (NCT03115983) to evaluate decompression and stabilization with an investigational dynamic sagittal tether (DST) vs decompression and Transforaminal Lumbar Interbody Fusion (TLIF) for patients with symptomatic grade I lumbar degenerative spondylolisthesis with spinal stenosis.
Twenty-five baseline covariates were selected for their expected relationship to patient outcomes or enrollment bias. Subclassification by PS quintiles was used to design a sample of investigational DST patients and TLIF controls with excellent covariate balance in which to estimate causal treatment effects. Additionally, balance in PS covariates was compared to available matching covariates from seven randomized spine IDE trials.
The PS subclassification design resulted in excellent balance across baseline covariates, as evidenced by small standardized mean differences and no significant between group differences after accounting for the PS design (all ≥ 0.768). Differences in SMDs among covariates of randomized spine IDE trials were not significant ( = 0.396).
The PS subclassification design achieved excellent covariate balance between DST investigational and TLIF control participants. This PS designed sample shows covariate balance similar to that observed in published studies in which patients were randomized to investigational or control arms.Clinical trial registered with https://www.clinicaltrials.gov (NCT03115983).
前瞻性观察性倾向评分。
当治疗不设盲且患者对治疗组有强烈偏好时（如在脊柱器械试验中），随机分组可能导致偏差。本报告描述了为一项研究性器械豁免（IDE）试验（NCT03115983）开发倾向评分（PS）模型所采用的基本原理和方法，该试验旨在评估使用研究性动态矢状束带（DST）进行减压和稳定与减压及经椎间孔腰椎椎体间融合术（TLIF）治疗有症状的I级腰椎退行性滑脱伴椎管狭窄患者的疗效。
根据25个基线协变量与患者预后或入组偏差的预期关系进行选择。通过PS五分位数进行亚分类，以设计一个研究性DST患者和TLIF对照的样本，该样本具有良好的协变量平衡，用于估计因果治疗效果。此外，将PS协变量的平衡与来自七项随机脊柱IDE试验的可用匹配协变量进行比较。
PS亚分类设计在基线协变量之间实现了良好的平衡，标准化平均差异较小，且在考虑PS设计后组间无显著差异（均≥0.768），这证明了该设计的有效性。随机脊柱IDE试验协变量之间的标准化平均差异无统计学意义（P = 0.396）。
PS亚分类设计在DST研究组和TLIF对照组参与者之间实现了良好的协变量平衡。这个PS设计的样本显示出与已发表研究中观察到的协变量平衡相似，在这些研究中患者被随机分配到研究组或对照组。临床试验已在https://www.clinicaltrials.gov注册（NCT03115983）。
