Six Minute Walk Test Changes during Long-Term Acute Care Hospital Rehabilitation for Patients Post COVID-19

RESEARCH OBJECTIVES: To explore Six Minute Walk Test (6MWT) improvements in patients admitted to long-term acute care hospitals (LTACHs) for severe and prolonged SARS-Cov-2 illness (COVID-19). DESIGN: National retrospective longitudinal cohort. SETTING: Five LTACHs in USA. PARTICIPANTS: 184 (77.3% of 238 total) participants post-COVID-19 [mean age 64.5 (13.1) years] for whom 6MWT scores were available at admission and discharge. INTERVENTIONS: Participants received standard inpatient LTACH care. 6MWT distance measured using established procedures. MAIN OUTCOME MEASURES: 6MWT distance change. We defined improvement as 54m, which is the minimal clinically important difference (MCID) identified for individuals with pulmonary diseases . RESULTS: Prior to LTACH transfer, participants’ average hospitalization length of stay was 30.9 days (SD=20.1), with 85% staying in an ICU for ≥3 days, 58% diagnosed with acute respiratory distress syndrome, 65% receiving mechanical ventilation, and 30% having tracheostomies. During LTACH stay, average 6MWT distance increased from admission [median 0m (IQR 0-0)] to discharge [median 13.4m (IQR, 0-82)], with 32% of participants exceeding the MCID. The discharge average 6MWT distance for those who improved was 180.9m (SD=112.5; range=61-592) versus 10.1m (SD=17.8; range=0-95.7) for those without improvement. Patients who improved were younger (60.8 vs. 66.3 years; p=0.01), ventilated for less time (18.7 vs 26.9 days; p=0.004) and were less likely to have a tracheostomy (15.5% vs 37.9%; p=0.002). CONCLUSIONS: Among a national cohort of patients with the most severe and prolonged COVID-19 illness, nearly one-third had improved 6MWT distance exceeding established MCID thresholds. Short distances traversed by those not exceeding the MCID confirm persisting mobility dysfunction expected to hinder community participation. Even for those exceeding the MCID threshold, many did not achieve the 6MWT distance threshold of 205m previously identified as discriminating between home and community ambulators. Collectively, findings highlight the need for further research to identify strategies (medical, therapeutic) to enhance walking during rehabilitation and post discharge for patients cared for in LTACH settings following hospitalization for COVID-19. AUTHOR(S) DISCLOSURES: Research supported by grants from NALTH and the National Institute on Aging (PI: Makam).