The five-repetition sit-to-stand test (5STS) is reliable, valid and responsive in patients with COPD, providing a more practical alternative to tests such as the 6-minute walk test or incremental shuttle walk test for measuring functional outcomes, according to U.K. researchers.
Investigators compared 5STS results in 50 patients with COPD to data collected from the incremental shuttle walk (ISW), quadriceps maximum voluntary contraction (QMVC), St George’s Respiratory Questionnaire (SGRQ) and Age Dyspnoea Obstruction index (ADO), BODE index (iBODE). Responsiveness was determined by measuring 5STS before and after outpatient pulmonary rehabilitation (PR) in 239 patients. Minimum clinically important difference (MCID) was estimated using anchor-based methods.
The 5STS results significantly correlated with several measures of exercise capacity, including the incremental shuttle walk test, and lower limb muscle strength, as measured by quadriceps maximum voluntary contraction. Poorer scores were associated with worse health-related quality of life and dyspnea, as well as worsening prognosis indices. However, there was no association with FEV1.
Being quick and cheap to perform gives the 5STS an advantage over other tests, according to the authors. They also noted that it takes limited space, making it feasible for most healthcare settings including the outpatient clinic and home.
Researchers noted that in patients with very poor function, alternatives such as the habitual gait speed over 4m or a battery of physical tests might be more appropriate due to a “floor effect,” caused by 15% of their sample being unable to complete the test.