Rasch analysis of the Indian vision function questionnaire

Abstract

The general functioning scale of the IND-VFQ consists of two separate unidimensional constructs: visual functioning and mobility. Both these Rasch scaled versions with good psychometric properties are effective tools for the assessment of visually impaired patients in India.

Traditional and Rasch psychometric analyses of the Quality of Life in Adult Cancer Survivors (QLACS) questionnaire in shorter-term cancer survivors 15months post-diagnosis

“…never and seldom) after any reverse scoring. Item fit was assessed using the information-weighted 'infit' meansquare statistic (infit.MnSq), where a value of 1 indicates perfect fit, and values between 0.7 and 1.3 are generally viewed as indicating acceptable fit [46][47][48][49]. Misfitting items outside these limits were iteratively removed, until all remaining items demonstrated fit.…”

Psychometric evaluation of the Revised Illness Perception Questionnaire (IPQ-R) in cancer patients: Confirmatory factor analysis and Rasch analysis

“…Separation statistics ≥2 are generally viewed as a benchmark [41,48,49]. Person reliability, the Rasch equivalent of Cronbach's alpha, was also calculated; values ≥0.70 are seen to indicate acceptable reliability [48][49][50].…”

“…MnSq), where a value of 1 indicates perfect fit, and values between 0.7 and 1.3 are generally viewed as indicating acceptable fit [41,42]. Misfitting items outside these limits were iteratively removed, until all remaining items demonstrated fit.…”

“…Following convention, DIF was evaluated using the criterion of a significant difference of N|0.5| logit between subgroups [41,43]. To control for multiple testing, significance was set at p b .001 (for a strict Bonferroni correction, α = .0003).…”

“…To control for multiple testing, significance was set at p b .001 (for a strict Bonferroni correction, α = .0003). Differences of b|1.0| logit were considered to indicate minor DIF, and differences of ≥|1.0| logit, notable DIF [41,44].…”