{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:30:46Z","timestamp":1760236246764,"version":"build-2065373602"},"reference-count":21,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,12]],"date-time":"2021-11-12T00:00:00Z","timestamp":1636675200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>COVID-19 survivors are associated with acute respiratory failure (ARF) and show a high prevalence of impairment in physical performance. The present studied aimed to assess whether we may cluster these individuals according to an exercise test. The presented study is a retrospective analysis of 154 survivors who were admitted to two hospitals of Istituti Clinici Scientifici Maugeri network, Italy. Clinical characteristics, walked distance, heart rate (HR), pulse oximetry (SpO2), dyspnoea, and leg fatigue (Borg scale: Borg-D and Borg-F, respectively) while performing the six-minute walking test (6MWT) were entered into unsupervised clustering analysis. Multivariate linear regression identified variables that were informative for the set of variables used for cluster definition. Cluster 1 (C1: 86.4% of participants) and Cluster 2 (C2: 13.6%) were identified. Compared to C1, the individuals in C2 were significantly older, showed significantly higher increase in fatigue and in dyspnoea, greater reduction in SpO2, and a lower HRpeak during the test. The need of walking aids, time from admission to acute care hospitals, age, body mass index, endotracheal intubation, baseline HR and baseline Borg-D, and exercise-induced SpO2\u00a0change were significantly associated with the variables that were used for cluster definition. Different characteristics and physiological parameters during the 6MWT characterise survivors of COVID-19-associated ARF. These results may help in the management of the long-term effects of the disease.<\/jats:p>","DOI":"10.3390\/ijerph182211868","type":"journal-article","created":{"date-parts":[[2021,11,12]],"date-time":"2021-11-12T08:10:22Z","timestamp":1636704622000},"page":"11868","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Clusters of Survivors of COVID-19 Associated Acute Respiratory Failure According to Response to Exercise"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9389-7915","authenticated-orcid":false,"given":"Michele","family":"Vitacca","sequence":"first","affiliation":[{"name":"Respiratory Rehabilitation of the Institute of Lumezzane, Istituti Clinici Scientifici Maugeri IRCCS, 25065 Lumezzane, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3982-2098","authenticated-orcid":false,"given":"Mara","family":"Paneroni","sequence":"additional","affiliation":[{"name":"Respiratory Rehabilitation of the Institute of Lumezzane, Istituti Clinici Scientifici Maugeri IRCCS, 25065 Lumezzane, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alberto","family":"Malovini","sequence":"additional","affiliation":[{"name":"Laboratory of Informatics and Systems Engineering for Clinical Research of the Institute of Pavia, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Annalisa","family":"Carlucci","sequence":"additional","affiliation":[{"name":"Respiratory Rehabilitation of the Institute of Pavia, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy"},{"name":"Department of Medicine and Surgery, Universit\u00e0 Insubria, 21100 Varese, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chiara","family":"Binda","sequence":"additional","affiliation":[{"name":"Respiratory Rehabilitation of the Institute of Pavia, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy"},{"name":"Department of Medicine and Surgery, Universit\u00e0 Insubria, 21100 Varese, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vincenzo","family":"Sanci","sequence":"additional","affiliation":[{"name":"Respiratory Rehabilitation of the Institute of Pavia, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5331-1393","authenticated-orcid":false,"given":"Nicolino","family":"Ambrosino","sequence":"additional","affiliation":[{"name":"Respiratory Rehabilitation of the Institute of Montescano, Istituti Clinici Scientifici Maugeri IRCCS, 27040 Montescano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,12]]},"reference":[{"key":"ref_1","unstructured":"Johns Hopkins Coronavirus Resource Center (2021, September 23). 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