Defining Severity Levels for Post-Stroke Upper Limb Motor Impairment and Activity Limitation: A Systematic Review

Background Stroke often results in upper limb motor impairment and activity limitation, however terminology to describe severity levels vary. This hinders data pooling from clinical trials to inform practice. There are no reviews that have synthesized severity levels of stroke-related upper limb motor impairment or activity limitation. Objective To systematically review published literature on descriptors of severity levels for post-stroke upper limb motor impairment and activity limitation. Methods Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched eight major databases. Inclusion criteria: primary research studies, adults post-stroke, severity of upper limb motor impairment and/or activity limitation described. We classified included papers by assessing descriptor precision: ‘green’ (studies including descriptors that used recommended outcome measures, cut-offs or central tendency and dispersion), ‘red’ (descriptors only), and ‘amber’ (remaining studies). Of the ‘green’ studies, we identified the most commonly reported descriptors and measures, and computed cut-off scores using non-parametric statistics. Results From 17,273 records, 750 studies were included. The most commonly used severity descriptors were ‘mild, and/or moderate, and/or severe,’ used in 580 (77%) of studies. For the Fugl-Meyer Assessment (Upper Extremity) (57 studies, 8% of the total number of studies included), ‘severe’ ranged from 0 to 25, ‘moderate’ from 26 to 50, and ‘mild’ from 51 to 66. Limited data from the remaining studies prevented further analysis. Conclusions Our review highlights a lack of standardization of the operationalization of ‘severity’ of post-stroke upper limb motor impairment and activity limitation. It provides a foundation for developing a standardized clinical language to describe severity levels to improve research and clinical practice.