The 1-minute sit-to-stand test to detect desaturation during 6-minute walk test in interstitial lung disease

Although the 6 min walk test (6MWT) is well-established for assessing desaturation in patients with interstitial lung disease (ILD), it cannot be easily performed in primary healthcare settings. This retrospective observational study aimed to evaluate the usefulness of the 1 min sit-to-stand test (1STST) for assessing desaturation during 6MWT in ILD patients with normal resting blood oxygen levels. We included 116 patients, and the pulse oxygen saturation (SpO2) for both methods was analyzed. The SpO2 nadir during the 1STST and 6MWT correlated strongly (ρ = 0.82). The frequency of patients with nadir SpO2 < 90% was consistent for both tests (κ = 0.82). 1STST was superior to diffusing capacity for carbon monoxide in detecting desaturation during the 6MWT. These findings were similarly stratified according to performance status or dyspnea scale. The 1STST can easily measure exertional desaturation in ILD patients with normal resting blood oxygen levels and is an alternative to the 6MWT.