运用项目反应理论（IRT）提高溃疡性结肠炎患者简单临床结肠炎活动指数（SCCAI）的效率。

Using item response theory (IRT) to improve the efficiency of the Simple Clinical Colitis Activity Index (SCCAI) for patients with ulcerative colitis.

作者信息

Walsh Alissa, Cao Rena, Wong Darren, Kantschuster Ramona, Matini Lawrence, Wilson Jean, Kormilitzin Andrey, South Matthew, Travis Simon, Bauermeister Sarah

机构信息

Translational Gastroenterology Unit, NIHR Oxford Biomedical Research Centre, Nuffield Department of Experimental Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.

Department of Psychiatry, University of Oxford, Oxford, UK.

出版信息

BMC Gastroenterol. 2021 Mar 22;21(1):132. doi: 10.1186/s12876-021-01621-y.

DOI:10.1186/s12876-021-01621-y

PMID:33752610

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7983213/

Abstract

BACKGROUND

The SCCAI was designed to facilitate assessment of disease activity in ulcerative colitis (UC). We aimed to interrogate the metric properties of individual items of the SCCAI using item response theory (IRT) analysis, to simplify and improve its performance.

METHODS

The original 9-item SCCAI was collected through TrueColours, a real-time software platform which allows remote entry and monitoring of patients with UC. Data were securely uploaded onto Dementias Platform UK Data Portal, where they were analysed in Stata 16.1 SE. A 2-parameter (2-PL) logistic IRT model was estimated to evaluate each item of the SCCAI for its informativeness (discrimination). A revised scale was generated and re-assessed following systematic removal of items.

RESULTS

SCCAI data for 516 UC patients (41 years, SD = 15) treated in Oxford were examined. After initial item deletion (Erythema nodosum, Pyoderma gangrenosum), a 7-item scale was estimated. Discrimination values (information) ranged from 0.41 to 2.52 indicating selected item inefficiency with three items < 1.70 which is a suggested discriminatory value for optimal efficiency. Systematic item deletions found that a 4-item scale (bowel frequency day; bowel frequency nocturnal; urgency to defaecation; rectal bleeding) was more informative and discriminatory of trait severity (discrimination values of 1.50 to 2.78). The 4-item scale possesses higher scalability and unidimensionality, suggesting that the responses to items are either direct endorsement (patient selection by symptom) or non-endorsement of the trait (disease activity).

CONCLUSION

Reduction of the SCCAI from the original 9-item scale to a 4-item scale provides optimum trait information that will minimise response burden. This new 4-item scale needs validation against other measures of disease activity such as faecal calprotectin, endoscopy and histopathology.

摘要

背景

SCCAI旨在促进溃疡性结肠炎（UC）疾病活动的评估。我们旨在使用项目反应理论（IRT）分析来探究SCCAI各个项目的度量属性，以简化并改善其性能。

方法

最初的9项SCCAI是通过TrueColours收集的，这是一个实时软件平台，可允许对UC患者进行远程录入和监测。数据被安全地上传到英国痴呆症平台数据门户，在那里使用Stata 16.1 SE进行分析。估计了一个双参数（2-PL）逻辑IRT模型，以评估SCCAI每个项目的信息量（区分度）。在系统地删除项目后生成并重新评估了一个修订量表。

结果

对牛津治疗的516例UC患者（41岁，标准差=15）的SCCAI数据进行了检查。在最初删除项目（结节性红斑、坏疽性脓皮病）后，估计了一个7项量表。区分度值（信息量）范围为0.41至2.52，表明所选项目效率低下，其中三个项目<1.70，而1.70是最佳效率的建议区分度值。系统的项目删除发现，一个4项量表（日间排便频率；夜间排便频率；排便急迫感；直肠出血）对特征严重程度更具信息量和区分度（区分度值为1.50至2.78）。4项量表具有更高的可扩展性和单维性，这表明对项目的回答要么是直接认可（按症状选择患者），要么是不认可该特征（疾病活动）。