Reliability and validity of subjective measures of aerobic intensity in adults with spinal cord injury: a systematic review

Objective: To systematically synthesize and appraise research regarding test-retest reliability or criterion validity of subjective measures for assessing aerobic exercise intensity in adults with spinal cord injury (SCI). Data Sources: Electronic databases (Pubmed, PsychINFO, SPORTDiscus, EMBASE and CINAHL) were searched from inception to 1-1-2016. Study Selection: Studies involving at least 50% of participants with SCI who performed an aerobic exercise test that included measurement of subjective and objective intensity based on test-retest reliability or criterion validity protocols. Data Extraction: Characteristics were extracted on study design, measures, participants, protocols, and results. Each study was evaluated for risk of bias based on strength of the study design and a quality checklist score (COnsensus-based Standards for the selection of health Measurement Instruments [COSMIN]). Data Synthesis: The seven eligible studies (one for reliability, six for validity) evaluated overall, peripheral and/or central ratings of perceived exertion on a 6-20 scale (RPE 6-20). No eligible studies were identified for other subjective intensity measures. The evidence for reliability and validity were synthesized separately for each measure, and assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Overall, very low GRADE confidence ratings were established for reliability and validity evidence generalizable to the entire population with SCI and various upper-body and lower-body modalities. There was low confidence for the evidence showing that overall RPE 6-20 has acceptable validity for adults with SCI and high fitness levels performing moderate to vigorous-intensity upper-body aerobic exercise. Conclusions: Health care professionals and scientists need to be aware of the very low to low confidence in the evidence, which currently prohibits a strong clinical recommendation for the use of subjective measures for assessing aerobic exercise intensity in adults with SCI. However, a tentative, conditional recommendation regarding overall RPE 6-20 seems applicable depending on participants’ fitness level as well as the exercise intensity and modality used.