Physical Function Differences by COVID-19 Status: A Cross-sectional Analysis From the RECOVER Adult Cohort

Importance Many adults with prior SARS-CoV-2 infection have persistent limitations, but few studies have examined objective physical function impairment that persist longer than 3 months after infection. Objective The objective was to characterize physical function impairment among adults with and without SARS-CoV-2 infection. Design This study was a retrospective, cross-sectional analysis. Setting Researching COVID to Enhance Recovery (RECOVER) initiative, a multi-site observational study in the United States (ClinicalTrials.gov: NCT05172024). Participants Participants were adults ≥18 years old with and without SARS-CoV-2 infection. Exposures Groups were defined based on COVID-19 status at enrollment: never diagnosed (control), diagnosed with COVID-19 ≤ 12 weeks (recent COVID-19), or > 12 weeks prior to enrollment (remote COVID-19). The RECOVER-Adult Long COVID Index was used to further characterize by Index ≥12 versus 0. Main Outcomes/Measures Physical function (main outcome) was assessed by number of repetitions on a 30-second sit-to-stand test (30STS). Results 30STS assessments at enrollment were available from 11,578 participants. 30STS repetitions were lowest in the remote COVID-19 group (n = 4942) with 11.5 (SD = 4.2) repetitions compared to 12.5 (SD = 4.7) repetitions among controls (n = 1887) or 12.2 (SD = 4.5) in recent COVID-19 (n = 4698). Remote COVID-19, but not recent COVID-19, was associated with lower physical function in the adjusted model (-0.61 repetitions; SD = 0.21). Those with RECOVER Long COVID Research Index ≥12 performed 1.6 (SD = 0.2) fewer repetitions than those with an Index equal 0. Conclusions Physical function impairment did not show clinically meaningful group differences between RECOVER Adult Cohort participants by COVID-19 status, or by Long COVID Index. Individual responses over time or in response to an intervention may be more clinically relevant. Relevance In the RECOVER adult cohort, overall physical function differences by time since COVID-19 or by Long COVID Index were small. Individualized assessments are needed to determine functional impairment following COVID-19 diagnosis and subsequent steps for rehabilitation interventions.