Patient-reported outcome measures (PROMs) used among liver transplant recipients: a systematic review and methodological quality appraisal

Aim: To identify instruments used to measure patient-reported outcomes after LT, and critically evaluate their measurement properties.

Methods: Five online databases were searched to find English-language LT-specific PROMs from their inception to October 2024. Studies describing the development or validation of PROMs were included. Two reviewers extracted and synthesized information about the characteristics of the studies and instruments. The methodological quality of the included studies was evaluated using the Consensus-Based Standards for the Selection of Health Measurement Instrument (COSMIN). Two reviewers independently evaluated the methodological quality of the included instruments.

Results: A total of 17 studies involving 14 PROMs met the inclusion criteria and were included in this review. The included PROMs assessed a range of outcomes, including health-related quality of life, therapeutic adherence, symptom experience, social participation, feeling for the donor, satisfaction and informational needs. None of the 14 scales reported the ten boxes of measurement properties outlined by the COSMIN. Among all the measurement properties, content validity from expert (64.3%, 9/14) and internal consistency (57.1%, 8/14) were the two most frequently measured attributes. Less than half of the studies evaluated the content validity from the patients' perspective. Four studies evaluated structural validity using exploratory factor analysis, but no study conducted confirmatory factor analysis or used IRT method to measure the structural validity.

Conclusion: This systematic review provided an overall picture and detailed analysis of LT-specific PROMs, and highlighted the paucity of well-developed and validated instruments. Further studies are urgently needed, both in terms of exploring patients' health concerns after LT and validating the instruments.

Reporting method: This study is reported according to the PRISMA Statement.