Clinimetric properties of field exercise tests in cystic fibrosis: a systematic review

Accurate measurement of exercise capacity is an important prognostic indicator for people with cystic fibrosis (pwCF); however, gold-standard, cardiopulmonary exercise tests are commonly unavailable. This review systematically describes the clinimetric properties of field exercise tests for pwCF.

A systematic review was undertaken for studies reporting field exercise tests in pwCF. Four electronic databases were searched for studies published from 1990 to January 2024. Where available, clinimetric properties reported included reliability, validity, responsiveness and interpretability.

4041 studies were identified with 153 eligible for inclusion. 10 different field exercise tests were described, including six walk/run tests (incremental shuttle walk test (ISWT), modified shuttle test-15 levels (MST-15), MST-25 levels (MST-25), 20-m shuttle test, 6-min walk test (6MWT) and 12-min walk test (12MWT)), three step tests (3-min step test (3MST), incremental step test and Alfred step test (A-STEP)) and the 1-min sit-to-stand test (1STS). Reliability was found for the ISWT, MST-15, 6MWT, 1STS and 3MST (intraclass correlation coefficients >0.80). The ISWT, MST-15 and 6MWT were found to be valid (concurrent and discriminate). Responsiveness was supported for the 6MWT only. Four tests (MST-15, 6MWT, 3MST and 1STS) demonstrated ceiling effects.

This review supports the reliability, validity and responsiveness of the 6MWT in pwCF. The ISWT and MST-15 were found to be valid. The 1STS is reliable and feasible, but its utility is limited by ceiling effects. The 3MST, MST-25, 20-m shuttle test, incremental step test, A-STEP and 12MWT require further investigations of their clinimetric properties.