EVALUATING THE RESPONSIVENESS OF THE PATIENT REPORTED OUTCOMES, BURDENS AND EXPERIENCES (PROBE) QUESTIONNAIRE

Abstract

BACKGROUND. The study of patient reported outcomes (PROs) has seen an exponential increase in recent years. In order to be useful in practice, PRO questionnaires should be evaluated for validity, reliability, and responsiveness. Responsiveness, which assesses a questionnaire’s ability to capture changes in quality of life (QOL) when they occur, has not formally been evaluated in hemophilia-specific questionnaires. PRIMARY OBJECTIVE. To evaluate the responsiveness of the Patient Reported Outcomes, Burdens, and Experiences (PROBE) questionnaire in individuals living with hemophilia A or B following events of interest. SECONDARY OBJECTIVES. To evaluate the responsiveness of PROBE over periods in which no events occur. To explore the use of regression analysis in aiding interpretability. To assess the presence of response shift in the study population. METHODS. Participants will be asked to complete PROBE, as well as questions indicating changes in QOL, following a bleed or surgical intervention, and every 6 months. Responses will be evaluated using anchor-based and distribution-based approaches. OUTCOMES. Minimally important differences (MIDs) and minimally detectable changes (MDCs) will be calculated, graphically represented, and compared to determine a single or small range of MID values. STUDY IMPLICATIONS. Understanding responsiveness will provide increased interpretability of PROBE scores. Using an MID value, one can be confident that a change in PROBE score greater than the MID is beyond measurement error and indicates a change in QOL. This will allow for the use of PROBE in future research trials of drug effectiveness and can offer patients’ perspectives on their changes in QOL when switching to novel therapies. In addition, physicians may be able to use PROBE as a method of tracking and better understanding changes in their patients’ health statuses in the clinical setting.