Internal structure validity and internal consistency reliability of the Minnesota Living with Heart Failure Questionnaire: a systematic review protocol

IntroductionThe Minnesota Living with Heart Failure Questionnaire (MLHFQ) is one of the most used tools to measure health-related quality of life in heart failure. Despite extensive use in research, evidence on the MLHFQ's internal structure validity remains heterogeneous and inconclusive. There are no known reviews that systematically summarise the evidence related to the MLHFQ's factor structure (internal structure validity). This gap highlights a need to critically appraise, summarise and compare the available evidence on the internal structure and internal consistency reliability (ICR) of the MLHFQ.Methods and analysisThe review will adhere to the reporting guidelines of the Cochrane Handbook for Systematic Reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. We will systematically search eleven electronic databases/search engines (Medline, EMBASE, Cumulative Index for Nursing and Allied Health Literature, PsycINFO, Global Health, Health and Psychosocial Instruments, Scopus, Journals, Web of Science, Google Scholar, and Dissertation and Theses Global) for quantitative studies assessing the MLHFQ's factor structure and ICR. Two reviewers will then independently screen studies for eligibility and assess the quality of included studies using the COnsensus-based Standards for the selection of health status Measurement Instruments checklist. Throughout the review, discrepancies will be resolved through consensus or by the involvement of the third reviewer. We will analyse and present results using descriptive statistics (frequencies, proportions and ranges) and narrative synthesis. We will include all the relevant studies published within the timeframe covered by the database. We carried out the preliminary search in November 2022 except for Dissertation and Theses Global which was searched in September 2023; however, we will update the entire search right before the review completion in January 2024.Ethics and disseminationEthical approval is not required as no primary data is being collected from individuals. We intend to share the findings of the review at international conferences and publish manuscripts in peer-reviewed journals.PROSPERO registration numberCRD42023346919.