Outcome measures within exercise-based rehabilitation interventions for people with long-term conditions: an analysis based on an overview of systematic reviews

<bold>Background:</bold> The similarities of disease-related symptoms (e.g., fatigue, reduced physical capacity) across long-term conditions (LTCs) and the evidence for widespread health benefits of exercise supports the need for rehabilitation services that include multiple LTCs. If exercise-based rehabilitation is to be developed for those with multiple LTCs, there is need of a consensus on relevant outcome measures. <bold>Aim:</bold> To determine which outcomes have been used in rehabilitation trials for single LTCs to inform the development of a core outcome set for future studies in people with multiple LTCs. <bold>Methods:</bold> An overview of systematic reviews assessing the impact of exercise-based interventions for LTCs. We extracted outcome measures from trials included within reviews that showed effectiveness and organised these into outcome domains. <bold>Results:</bold> 29 outcome domains across 1020 measures were reported in 30 reviews conducted across 25 LTCs. The most common outcome domains were health-related quality of life (HRQOL) and exercise capacity (number of LTCs=both 22). Short Form-36 (number of studies [k]=16) and EuroQoL-5D (k=9) were the most common measures for HRQOL, and six-minute walk test (k=17) and VO2max/peak (k=15) for exercise capacity. Other common domains (and measures) included strength (LTCs=17; handgrip [k=12], sit-to-stand [k=12]) and body composition (LTCs=14; BMI [k=8], body weight [k=7]). <bold>Conclusion:</bold> Given the wide range of outcome measures and domains reported in previous exercise-based intervention research across individual LTCs, there is urgent need to derive a core outcome set for future trials in those with multiple LTCs.