Systematic literature review and assessment of patient-reported outcome instruments in sickle cell disease

Abstract Background Sickle cell disease (SCD) is a chronic condition associated with high mortality and morbidity. It is characterized by acute clinical symptoms such as painful vaso-occlusive crises, which can impair health-related quality of life (HRQL). This study was conducted to identify validated patient-reported outcome (PRO) instruments for use in future trials of potential treatments for SCD. Methods A systematic literature review (SLR) was performed using MEDLINE and EMBASE to identify United States (US)-based studies published in English between 1997 and 2017 that reported on validated PRO instruments used in randomized controlled trials and real-world settings. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist was used to assess the quality of PRO instruments. Results The SLR included 21 studies assessing the psychometric properties of 24 PRO instruments. Fifteen of those instruments were developed and validated for adults and 10 for children (one instrument was used in both children and young adults aged up to 21 years). Only five of the 15 adult instruments and three of the 10 pediatric instruments were developed specifically for SCD. For most instruments, there were few or no data on validation conducted in SCD development cohorts. Of the 24 PRO instruments identified, 16 had strong internal reliability (Cronbach’s α ≥0.80). There was often insufficient information to assess the content validity, construct validity, responsiveness, or test-retest reliability of the instruments identified for both child and adult populations. No validated PRO instruments measuring caregiver burden in SCD were identified. Conclusions The evidence on the psychometric properties of PRO instruments was limited. However, the results of this SLR provide key information on such tools to help inform the design of future clinical trials for patients with SCD in the US