Department of Rheumatology & Immunology, Singapore General Hospital, The Academia, Level 4, 20 College Road, Singapore, 169856, Singapore.
Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
Qual Life Res. 2020 Oct;29(10):2823-2833. doi: 10.1007/s11136-020-02535-0. Epub 2020 May 22.
We aimed to develop and calibrate an item bank to measure physical function (PF) in Singapore, a multi-ethnic city in Southeast Asia.
We recruited participants from community and hospital settings stratified for age and gender, with and without medical conditions to administer candidate pool of 61-items derived from the people's perspectives. We calibrated their responses using Samejima's graded response model of item response theory (IRT), including model assumptions, model fit, differential item functioning (DIF), and concurrent and known-groups validity.
496 participants (50% male; 41% above 50 years old; 33.3% Chinese, 32.7% Malay and 34.1% Indian; 35% without chronic illness) were included in the calibration of item bank. 6 items were excluded due to mis-fit and local dependence. Redundancies in the response level was collapsed and re-scoring, while preserving the 5-level response structure. We found the final 55-item PF bank had adequate fit to IRT assumptions of unidimensionality, local independence and monotonicity. Items generally showed discernible ceiling effects with latent scores between - 3.5 to + 1.5. We found no DIF with gender, ethnicity or education. The PF scores correlated in the hypothesized direction with self-reported global health (Spearman's rho = - 0.35, 95% confidence intervals - 0.43 to - 0.27) and discriminated between groups stratified by age, gender and medical conditions.
The 55-item Singapore PF item bank provides an adequate tool for measuring the lower end of PF, with greatest potential utility in healthcare settings where restoration to normal physical functioning is the goal of intervention.
我们旨在开发和校准一个适用于新加坡的体能（PF）项目库，新加坡是东南亚的一个多民族城市。
我们在社区和医院环境中按年龄和性别分层招募参与者，包括有和没有医疗条件的参与者，以管理源自人群视角的 61 项候选项目库。我们使用 Samejima 的项目反应理论（IRT）等级反应模型校准他们的反应，包括模型假设、模型拟合、差异项目功能（DIF）以及同期和已知群体有效性。
共有 496 名参与者（50%为男性；41%年龄在 50 岁以上；33.3%为华人、32.7%为马来人和 34.1%为印度人；35%没有慢性病）参与了项目库的校准。由于拟合不当和局部依赖，有 6 个项目被排除在外。对响应水平进行了冗余性的合并和重新评分，同时保留了 5 级响应结构。我们发现，最终的 55 项体能银行具有足够的 IRT 假设维度、局部独立性和单调性拟合度。各项目普遍显示出明显的上限效应，潜在分数在-3.5 到+1.5 之间。我们没有发现性别、种族或教育方面的 DIF。体能得分与自我报告的总体健康状况呈假设方向相关（Spearman's rho= -0.35，95%置信区间-0.43 至-0.27），并在按年龄、性别和医疗条件分层的组之间具有区分能力。
55 项新加坡体能项目库为测量体能的较低端提供了一个充分的工具，在以恢复正常身体功能为干预目标的医疗保健环境中具有最大的潜在效用。
