Understanding the value of the 1-Minute Sit-to-Stand test in preoperative functional assessment: beyond the lung, going towards a multidimensional framework?| Rassegna di Patologia dell'Apparato Respiratorio

Articolo

Dear Editor,

Preoperative evaluation before thoracic surgery requires more than the prediction of postoperative lung function. Although pulmonary function tests and imaging-based estimates remain central, perioperative outcomes are also shaped by exercise capacity, muscle performance, frailty, symptom burden, and overall tolerance to physiological stress ¹. This supports the need for practical tools able to capture global functional reserve in routine clinical assessment.

Cardiopulmonary exercise testing (CPET) is generally considered the most comprehensive method for assessing exercise capacity and perioperative risk ². However, CPET is not always available, requires specific expertise and equipment, and is not necessarily indicated for all patients. In particular, its use can be limited by severe musculoskeletal or neurological impairment, poor cooperation, or clinical conditions that preclude maximal or symptom-limited exercise testing. In everyday clinical practice, simpler field tests continue to have an important role within stepwise assessment pathways. They can help identify patients with preserved functional capacity, detect those who require further evaluation, and provide useful information for prehabilitation, perioperative planning, and postoperative monitoring. Among field tests, the 6-minute walk test (6MWT) has historically been the most widely used. It is simple, inexpensive, and clinically informative, but it requires a standardized corridor, staff time, and adequate space. These requirements may limit its feasibility in many outpatient clinics or surgical pathways. The 1-minute sit-to-stand test (1STS) has therefore attracted increasing interest as a rapid, practical, and space-saving alternative. Requiring only a standard chair and minimal equipment, it can be performed in small clinical settings and may provide clinically relevant information on exercise tolerance, lower-limb muscle function, exertional dyspnea, and functional reserve. Importantly, the 1STS should not be interpreted merely as a shorter substitute for the 6MWT. Although both tests provide information on functional capacity, they stress partly different physiological domains. The 6MWT mainly reflects integrated submaximal walking capacity over a longer period, whereas the 1STS challenges repeated sit-to-stand transitions, lower-limb muscle endurance, coordination, ventilatory response to effort, symptom perception, and behavioral factors such as confidence and pacing strategy. These dimensions may be particularly relevant in surgical candidates, because postoperative recovery depends not only on pulmonary mechanics, but also on global functional reserve, frailty, muscle performance, and the ability to tolerate repeated physiological stress. For this reason, the value of field exercise tests should not be judged only by their ability to independently predict postoperative complications, but by their contribution to a broader, multidimensional assessment of surgical risk. In this context, the recent study by Uzer et al. evaluating the predictive value of the 1STS compared with the 6MWT in patients undergoing thoracic surgery provides a useful opportunity to reconsider how the 1STS should be positioned in preoperative evaluation ³. In their study, preoperative 1STS and 6MWT results were analyzed in relation to postoperative outcomes, with the aim of clarifying whether these tools could support perioperative risk stratification. The authors reported that neither test independently predicted postoperative complications and concluded that functional assessments should not be used as standalone tools for perioperative risk stratification. We agree with this conclusion, which is consistent with the heterogeneous evidence regarding the predictive value of field exercise tests in surgical candidates. However, the absence of independent predictive value should not necessarily be interpreted as a negative finding. One of the most relevant contributions of the study is the demonstration of meaningful comparability between the 1STS and the 6MWT. The reported correlations between 1STS performance, FEV₁, 6MWT distance, and Borg dyspnea scores suggest that the 1STS captures clinically relevant dimensions of functional status. Moreover, the association between post-STS dyspnea and postoperative complications is particularly interesting, as it indicates that symptom perception during exertion may provide additional information beyond simple performance metrics or peripheral oxygen saturation. This is clinically relevant because functional reserve is not limited to cardiopulmonary capacity, but also includes muscle endurance, symptom burden, and the patient’s physiological response to exertion ⁴. A central issue is how the research question is framed. Asking whether the 1STS can predict postoperative complications “as well as traditional functional tests” may intrinsically lead to a negative interpretation, since traditional field tests themselves are not established standalone predictors of postoperative complications. The available literature on the 6MWT remains inconsistent: some studies have shown an association between shorter walking distance and increased postoperative risk, whereas others have failed to demonstrate a significant relationship ^5,6. Therefore, the most appropriate question may not be whether the 1STS can replace established predictors of postoperative complications, but whether it can serve as a practical screening tool within a stepwise preoperative assessment strategy.

In line with this view, preliminary data from Sebio-Garcia et al. showed a strong association between relative VO₂peak and 1STS performance in patients awaiting lung cancer surgery, supporting the potential role of the 1STS as a simple screening tool to identify patients who may require more comprehensive functional evaluation ⁷. As concerns the Uzer et al. study, some methodological aspects should also be considered when interpreting the findings. First, the study population appeared to be relatively low risk, with preserved baseline functional status and generally acceptable pulmonary function. This may have reduced the discriminatory ability of performance-based tests, making it more difficult to detect differences between patients who did and did not develop complications. Second, the limited number of postoperative events in relation to the number of variables included in the multivariable model may have affected the stability of the regression analysis and increased the risk of overfitting. Third, the study does not clearly report whether functional tests were repeated or whether standardized procedures were applied. This is relevant because field exercise tests are affected by learning effects, familiarization, pacing strategy, confidence, and symptom perception. Current ERS/ATS standards recommend repeated testing for the 6MWT because of the documented learning effect ⁸, and similar considerations have been reported for the 1STS, for which repeated measurements may improve reliability (Tab. I) ⁹. From this perspective, the 1STS should not be dismissed because it fails to independently predict postoperative complications. Rather, its potential value lies in its feasibility, reproducibility, and ability to provide complementary information on functional status. In thoracic surgery candidates, it may help identify patients who require more detailed assessment, such as cardiopulmonary exercise testing, ventilation-perfusion evaluation, or targeted prehabilitation. It may also be particularly useful in settings where the 6MWT is difficult to perform because of space, time, staffing, or logistical constraints. Overall, the 1STS may not be a standalone predictor of postoperative complications, but perhaps it does not need to be. Its clinical relevance should be judged not by whether it replaces traditional functional tests or established risk models, but by whether it supports multidimensional risk assessment, identifies patients who require further evaluation, and helps select those who may benefit from preoperative optimization or targeted prehabilitation. Future studies should evaluate the 1STS within integrated preoperative pathways, using standardized protocols, repeated measurements, and clinically meaningful outcomes that extend beyond binary postoperative complications.

History

Ricevuto/Received: 29/05/2026

Accettato/Accepted: 23/06/2026

Figure e tabelle

Riferimenti bibliografici

1. Orlandi R, Degiovanni S, Uslenghi C. Pulmonary function prediction in lung cancer resection candidates: the latest insights. Breathe (Sheff). 2025; 21:250041. DOI
2. Brunelli A, Charloux A, Bolliger CT. The European Respiratory Society and European Society of Thoracic Surgeons clinical guidelines for evaluating fitness for radical treatment (surgery and chemoradiotherapy) in patients with lung cancer. Eur J Cardiothorac Surg. 2009; 36:181-184. DOI
3. Uzer F, Keskin H, Aygun Z. Can the 1-minute sit-to-stand test predict postoperative complications as well as traditional functional tests?. Respir Med. 2026; 254:108730. DOI
4. Gillis C, Ljungqvist O, Carli F. Prehabilitation, enhanced recovery after surgery, or both? A narrative review. Br J Anaesth. 2022; 128:434-448. DOI
5. Lee H, Kim HK, Kang D. Prognostic value of 6-min walk test to predict postoperative cardiopulmonary complications in patients with non-small cell lung cancer. Chest. 2020; 157:1665-1673. DOI
6. Ha D, Mazzone PJ, Ries AL. The utility of exercise testing in patients with lung cancer. J Thorac Oncol. 2016; 11:1397-1410. DOI
7. Garcia RS, Quadflieg K, Chen YX. Association between one-minute sit-to-stand test and cardiorespiratory fitness in patients awaiting lung cancer surgery. Eur Respir J. 2025; 66DOI
8. Holland AE, Spruit MA, Troosters T. An official European Respiratory Society/American Thoracic Society technical standard: field walking tests in chronic respiratory disease. Eur Respir J. 2014; 44:1428-1446. DOI
9. Crook S, Büsching G, Schultz K. A multicentre validation of the 1-min sit-to-stand test in patients with COPD. Eur Respir J. 2017; 49:1601871. DOI