Outcome Measurement in Real World Studies of Revascularisation for Chronic Limb Threatening Ischaemia: a Scoping Review and Framework for Appraisal.

Abstract

Real world data are increasingly used to evaluate revascularisation outcomes in chronic limb threatening ischaemia (CLTI). However, variation in data availability, accuracy, completeness, and granularity may influence the validity of outcome measurement. This review mapped outcomes reported in real world studies of CLTI revascularisation, examined how data infrastructure limitations affected outcome measurement and developed a framework for appraising the validity of reported outcomes. This was a scoping review of observational studies evaluating CLTI revascularisation using standalone or linked national registry, administrative, and insurance based datasets. MEDLINE and Embase were systematically searched (2015 - 2025) for eligible studies. Extracted information included data source(s), country, outcome definitions, reporting frequency, time period(s) covered, and linkage status. Outcome measurement issues were assessed in relation to data infrastructure characteristics. Fifty five studies from 10 countries reported 293 outcomes (31 unique). Reporting was dominated by mortality, major amputation, and reintervention, collectively accounting for 47% of all reported outcomes. Composite outcomes including amputation free survival, major adverse limb events, and major adverse cardiovascular events contributed a further 19%. Outcome definitions were heterogeneous, with 22 definitions of reintervention identified. Linkage with civic death registers improved mortality ascertainment. Amputation and reintervention event capture was most robust in data infrastructures supporting granular limb specific procedural analysis. Patient reported outcome measures, patency, and wound healing were infrequently reported. Linkage between registries, administrative datasets and death registers strengthened reliability of long term outcome measurement. A framework for appraising real world studies of CLTI revascularisation reflects these observations. Outcome validity in real world studies of CLTI revascularisation is influenced by the characteristics of the underlying data infrastructures, particularly coding granularity and linkage capability. Greater standardisation of outcome definitions and improved integration of data infrastructures are required to support more reliable and interpretable real world evidence in CLTI.