UCB Pharma, Alfred-Nobel-Strasse 10, 40789, Monheim am Rhein, Germany.
Pharmerit International, Bethesda, MD, USA.
Qual Life Res. 2021 Mar;30(3):945-954. doi: 10.1007/s11136-020-02686-0. Epub 2020 Oct 31.
To evaluate the psychometric performance of the Ankylosing Spondylitis Quality of Life (ASQoL) scale in patients with non-radiographic axial spondyloarthritis (nr-axSpA) to assess its appropriateness as an outcome measure in future clinical studies.
Patients with active axSpA from a Phase III, randomized, double-blind, placebo-controlled trial (RAPID-axSpA, NCT01087762) were included (N = 325). Modified New York (mNY) classification criteria were used to classify patients as having ankylosing spondylitis or nr-axSpA; those with nr-axSpA were further categorized based on objective signs of inflammation. Psychometric properties of the ASQoL were assessed/documented using a mixture of modern psychometric methods and classical test theory methods. These included exploratory factor analysis and item response theory models to assess the domain structure, test the utility of a single domain relative to subdomains, assess bias, and generate statistics to guide an empirical scoring algorithm. The reliability and validity of scores were evaluated via internal consistency, test-retest reliability, concurrent validity, and known-groups validity. Score responsiveness was assessed via anchor-based clinically meaningful change, supplemented with empirical cumulative distribution function visualizations.
The ASQoL data were defined by four domains. However, a four-domain solution was found to be inferior to a bifactor solution in which the four domains were included within a total domain. Scoring statistics supported a unit-weighted total score. Within the nr-axSpA population with objective signs of inflammation, the ASQoL mean score had adequate reliability, validity, and ability to detect clinically meaningful change.
Our findings suggest that the ASQoL is an appropriate outcome measure in interventional clinical trials in patients with nr-axSpA.
评估强直性脊柱炎生活质量量表（ASQoL）在非放射学中轴型脊柱关节炎（nr-axSpA）患者中的心理测量性能，以评估其作为未来临床研究中结局测量指标的适宜性。
纳入了一项 III 期、随机、双盲、安慰剂对照试验（RAPID-axSpA，NCT01087762）中活动型 axSpA 患者（N=325）。采用改良纽约（mNY）分类标准将患者分类为强直性脊柱炎或 nr-axSpA；nr-axSpA 患者进一步根据炎症的客观指标进行分类。采用现代心理测量方法和经典测试理论方法相结合的方法评估/记录 ASQoL 的心理测量特性。这些方法包括探索性因子分析和项目反应理论模型，以评估域结构，测试单一域相对于子域的效用，评估偏差，并生成统计数据以指导经验评分算法。通过内部一致性、重测信度、同时效度和已知组有效性评估分数的可靠性和有效性。通过基于锚的临床有意义的变化评估得分的反应性，并用经验累积分布函数可视化进行补充。
ASQoL 数据由四个域定义。然而，发现四域解决方案不如双因子解决方案优越，其中四个域包含在总域内。评分统计数据支持单位加权总分。在有炎症客观指标的 nr-axSpA 人群中，ASQoL 平均得分具有足够的可靠性、有效性和检测临床有意义变化的能力。
我们的研究结果表明，ASQoL 是 nr-axSpA 患者干预性临床试验中合适的结局测量指标。
