Applying Rasch analysis to evaluate measurement equivalence of different administration formats of the Activity Limitation scale of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR)

Abstract

BackgroundElectronic formats of patient-reported outcome (PRO) measures are now routinely used in clinical research studies. When changing from a validated paper and pen to electronic administration it is necessary to establish their equivalence. This study reports on the value of Rasch analysis in this process.MethodsThree groups of US pulmonary hypertension (PH) patients participated. The first completed an electronic version of the CAMPHOR Activity Limitation scale (e-sample) and this was compared with two pen and paper administrated samples (pp1 and pp2). The three databases were combined and analysed for fit to the Rasch model. Equivalence was evaluated by differential item functioning (DIF) analyses.ResultsThe three datasets were matched randomly in terms of sample size (n = 147). Mean age (years) and percentage of male respondents were as follows: e-sample (51.7, 16.0 %); pp1 (50.0, 14.0 %); pp2 (55.5, 40.4 %). The combined dataset achieved fit to the Rasch model. Two items showed evidence of borderline DIF. Further analyses showed the inclusion of these items had little impact on Rasch estimates indicating the DIF identified was unimportant.ConclusionsDifferences between the performance of the electronic and pen and paper administrations of the CAMPHOR Activity Limitation scale were minor. The results were successful in showing how the Rasch model can be used to determine the equivalence of alternative formats of PRO measures.

Comparison of Patient‐ and Parent‐Reported Quality of Life for Patients Treated for Persistent Obstructive Sleep Apnea

“…5 These tools evaluate the patient's and the family's perceptions of the impact of the disease on their lives, and they have long been used for adults and children in various medical disciplines (eg, the evaluation of pain management, rheumatoid arthritis, and pulmonary hypertension). [6][7][8] Moreover, it was demonstrated that children as young as 5 years can self-report pain intensity when they use age-appropriate standardized instruments. 9,10 Given the importance of patient-reported outcome tools in measuring HRQOL and the dearth of literature regarding the effect of OSA treatment on QOL, our aim was to (1) evaluate the impact of the treatment of persistent OSA on QOL with these tools and (2) compare parent-and selfreported Pediatric Quality of Life Inventory (PedsQL) scores.…”

German translation, cultural adaption and validation of the unidimensional self-efficacy scale for multiple sclerosis: a study protocol

“…Person and summary item fit residuals reflect perfect model fit if their mean and SD are close to 0 and 1, respectively 87 88…”

Assessing the equivalence of Web-based and paper-and-pencil questionnaires using differential item and test functioning (DIF and DTF) analysis: a case of the Four-Dimensional Symptom Questionnaire (4DSQ)

“…Mean scores can then be compared between groups. This is a fairly weak design to assess measurement equivalence [ 7 ]. In the latter design, participants are randomly assigned to one of two study arms in which they either first complete the P&P PRO and then the ePRO or the other way around.…”

“…The research designs, discussed above, assess only a small aspect of true measurement equivalence because they fail to address equivalence of item-level responses [ 7 , 8 ]. Contemporary approaches to measurement equivalence employ differential item functioning (DIF) analysis [ 9 ].…”

“…Whereas DIF analysis dates back to at least the 1980s [ 12 ], the method is relatively new in mode of administration equivalence research. In a non-systematic search, we identified only a dozen such studies (e.g., [ 7 , 8 , 13 – 15 ]). The ISPOR ePRO good research practice task force report briefly mentioned DIF analysis as ‘another approach’ without giving the method much attention [ 2 ].…”