Is the 1-minute sit-to-stand test a good tool for the evaluation of the impact of pulmonary rehabilitation? Determination of the minimal important difference in COPD

Figures & data

Table 1 Baseline characteristics of the patients

Male/female, n	30/18
Age, year	64±9.8
BMI, kg/m^2	26.4±7
Smoking, pack-year	44.7±21.8
Dyspnea, mMRC	2.2±0.7
Charlson index	3.5±1.7
Lung function:
* FEV1, % predicted	52.3±16.9
* FVC, % predicted	77.6±19.6
* FEV1/FVC	54.4±12.5
* RV/TLC, % predicted	135.4±27.5
* MIP, % predicted#	79.8±20.2
Exercise testing:
* 6MWD, m	387.6±111
* 6MWD, %#	64±38
* 6MWT desaturation, n (%)	20 (42)
* QMVC, %#	72.5±21.8
* Peak O2 consumption, ml/min/kg	13.8±3
* Peak O2 consumption, %#	61.2±15.3
SGRQ total score	55.1 ± 15.1
HAD total score	16±6.8
BODE index	3.1±1.5

Notes: Data are presented as mean ± SD unless otherwise indicated. Post-bronchodilator results are provided in percentage of predicted value.

# Predicted values are from Uldry et al³⁵ for MIP, from Troosters et al³⁷ for the 6MWD, from Hogrel et al³⁸ for QMVC and from Hansen et al³⁹ for Peak O₂ consumption. 6MWT desaturation, fall of at least 4% of the SpO₂, and post-test SpO₂ <90% according to Wedzicha et al³⁶.

Abbreviations: BMI, body mass index; BODE, body mass index, airflow obstruction, dyspnoea and exercise capacity index; FEV₁, forced expiratory volume in 1s; FVC, forced vital capacity; HAD, hospital anxiety depression; MIP, maximal inspiratory pressure; mMRC, modified medical research council scale; 6MWD, 6-minute walk distance; QMVC, quadriceps maximum voluntary contraction; RV/TLC, residual volume/total lung capacity; SGRQ, saint george respiratory questionnaire.

Table 2 Main determinants of 1-minute STS repetitions at baseline (multivariate analysis)

Variables	b	Correlation coefficient (r)	P-value
6MWD, m	0.038	0.834	<10^−3
Height, cm	−0.438	−0.532	<10^−3
QMVC, Newton	0.016	0.236	0.065
b0	74.254

Notes: The predicted equation is based on a linear regression analysis with the following form: 1-minute STS repetitions = b0 + (b × 6MWD) + (b × height) + (b × QMVC) =74.254 + 0.038× 6MWD −0.438× height + 0.016 × QMVC).

Abbreviations: 6MWD, 6-minute walk distance; QMVC, quadriceps maximal voluntary contraction; STS, sit-to-stand.

Table 3 Change of the parameters measured during 1-minute STS test at baseline and at the end of PR

	Baseline	End	P-value
1-minute STS repetitions	19.2±6.1	23.0±7.7	<10^−3
Dyspnea, Borg scale	4.9±2.1	4.0± 1.7	0.025
HR, beats/min	101.3±15.7	101.9±15.3	0.705
SpO2, %	91.6±3.9	91.2±4.4	0.902

Notes: The test was performed at the inclusion (Baseline) and at the end of the PR (End). All the variables were measured at the end of each test (1 minute). Data presented as mean ± standard deviation.

Abbreviations: 6MWD, 6-minute walk distance; HR, heart rate; PR, pulmonary rehabilitation; QMVC, quadriceps maximal voluntary contraction; SpO₂, minimal pulse oxygen saturation percentage measured at the end of the test; STS, sit-to-stand.

Table 4 Comparisons between 1-minute STS repetitions, 6MWD and QMVC at baseline and the end of the PR

	Baseline	Change from baseline (absolute value)	Change from baseline (% baseline value)	P-value
1-minute STS repetitions	19.2±6.1	3.8±4.2	23±28	<10^−3
6MWD, m	387.6±111	45.3±47.7	15±17	<10^−3
QMVC, Newton	244.6±83.7	27.4±39.5	14±21	0.003

Notes: The tests were performed at the inclusion (Baseline) and at the end of the PR. Data presented as mean ± standard deviation.

Abbreviations: 6MWD, 6-minute walk distance; QMVC, quadriceps maximal voluntary contraction; STS, sit-to-stand.

Figure 1 Association between change in 1-minute STS test and change in (A) 6-minute walk distance (6MWD) and (B) quadriceps maximal voluntary contraction (QMVC) with pulmonary rehabilitation.

Note: (A and B) The black dotted line is the linear regression of the relation between the two variables.
Abbreviations: 6MWD, 6-minute walk distance; QMVC, quadriceps maximal voluntary contraction; STS, sit-to-stand.

Figure 2 Receiver operating characteristic curve for the identification of the minimal important difference of the 1-minute STS test using a 30 m improvement in 6-minute walk test as anchor.

Abbreviations: STS, sit-to-stand; AUC, area under curve.

UldryCFittingJWMaximal values of sniff nasal inspiratory pressure in healthy subjectsThorax19955043713757785009

 PubMed Web of Science ®Google Scholar

TroostersTGosselinkRDecramerMSix minute walking distance in healthy elderly subjectsEur Respir J199914227027410515400

 PubMed Web of Science ®Google Scholar

HogrelJYPayanCAOllivierGDevelopment of a French isometric strength normative database for adults using quantitative muscle testingArch Phys Med Rehabil200788101289129717908571

 PubMed Web of Science ®Google Scholar

HansenJESueDYWassermanKPredicted values for clinical exercise testingAm Rev Respir Dis19841292 Pt 2S49S556421218

 PubMed Web of Science ®Google Scholar

WedzichaJADomiciliary oxygen therapy services: clinical guidelines and advice for prescribers. Summary of a report of the Royal College of PhysiciansJ R Coll Physicians Lond199933544544710624659

 PubMedGoogle Scholar