Outcomes Among Patients Referred to Outpatient Rehabilitation Clinics After COVID-19 diagnosis

United States, January 2020-March 2021

Jessica S. Rogers-Brown, PhD; Valentine Wanga, PhD; Catherine Okoro, PhD; Diane Brozowsky, MBA; Alan Evans, DPT; David Hopwood, MSHI; Jennifer R. Cope, MD; Brendan R. Jackson, MD; Dena Bushman, MSN, MPH; Alfonso C. Hernandez-Romieu, MD; Robert A. Bonacci, MD; Tim McLeod, MPH; Jennifer R. Chevinsky, MD; Alyson B. Goodman, MD; Meredith G. Dixson, MD; Caitlyn Lufty, MPH; Julie Rushmore, PhD, DVM; Emily Koumans, MD; Sapna Bamrah Morris, MD; William Thompson, PhD


Morbidity and Mortality Weekly Report. 2021;70(27) 

In This Article

Abstract and Introduction


As of June 30, 2021, 33.5 million persons in the United States had received a diagnosis of COVID-19.[1] Although most patients infected with SARS-CoV-2, the virus that causes COVID-19, recover within a few weeks, some experience post–COVID-19 conditions. These range from new or returning to ongoing health problems that can continue beyond 4 weeks. Persons who were asymptomatic at the time of infection can also experience post–COVID-19 conditions. Data on post–COVID-19 conditions are emerging and information on rehabilitation needs among persons recovering from COVID-19 is limited. Using data acquired during January 2020–March 2021 from Select Medical* outpatient rehabilitation clinics, CDC compared patient-reported measures of health, physical endurance, and health care use between patients who had recovered from COVID-19 (post–COVID-19 patients) and patients needing rehabilitation because of a current or previous diagnosis of a neoplasm (cancer) who had not experienced COVID-19 (control patients). All patients had been referred to outpatient rehabilitation. Compared with control patients, post–COVID-19 patients had higher age- and sex-adjusted odds of reporting worse physical health (adjusted odds ratio [aOR] = 1.8), pain (aOR = 2.3), and difficulty with physical activities (aOR = 1.6). Post–COVID-19 patients also had worse physical endurance, measured by the 6-minute walk test (6MWT) (p<0.001) compared with control patients. Among patients referred to outpatient rehabilitation, those recovering from COVID-19 had poorer physical health and functional status than those who had cancer, or were recovering from cancer but not COVID-19. Patients recovering from COVID-19 might need additional clinical support, including tailored physical and mental health rehabilitation services.

Data were obtained from electronic health records (EHRs) of patients referred to Select Medical's outpatient rehabilitation clinics during January 2020–March 2021. Epidemiologic, clinical, and functional data from 1,295 post–COVID-19 patients and 2,395 control patients were examined. Post-COVID-19 patients were defined as those who were referred to a Select Medical facility for post–COVID-19 physical rehabilitation. Control patients, defined as those needing rehabilitation for a current or previous diagnosis of cancer with no history of an International Classification of Diseases, Tenth Revision (ICD-10) COVID-19 diagnosis code,§ were referred to a Select Medical cancer rehabilitation program. This control population was chosen because patients in this group completed the same initial evaluations as patients referred for post–COVID-19 rehabilitation. Information on type of cancer or interval since diagnosis was not available. Patient data were collected from EHRs and initial clinical evaluation, which included self-reported health measures and a 6MWT. At intake, self-reported measures and clinical evaluations were administered for health, physical endurance, and health care use.

Using validated scales, CDC assessed patients' mental and physical health, functional health, social participation ability, applied cognition, and physical endurance with Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health (version 1.2; National Institutes of Health), PROMIS Physical Function, PROMIS Ability, Quality of Life in Neurologic Disorders (Neuro-QoL),** and the 6MWT,†† respectively. For self-reported item-level data, five-point Likert scales were recoded to proportions. T-scores were computed for composite measures of physical and mental health, social participation ability, and applied cognition, where the summed raw scores were converted to T-scores based on standardized scoring tables; T-scores were designed to have a mean of 50 and a standard deviation (SD) of 10 for the general adult population Logistic regression analysis, adjusted for age and sex, was used to examine differences in patient-reported measures of health, physical endurance, and health care use between post–COVID-19 and control patients.§§ All analyses were conducted using SAS (version 9.4; SAS Institute). This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.¶¶

Post–COVID-19 patients referred for rehabilitation services differed from control patients by several characteristics, including sex, age, race, ethnicity, employment status, health insurance coverage, and U.S. Census region (Table 1). Compared with control patients, post–COVID-19 patients were more likely to be male, younger, in the labor force, insured by a commercial plan or a worker's compensation plan, and less likely to be covered by Medicaid or Medicare (Table 1). Post–COVID-19 patients were more likely to have received a diagnosis of generalized muscle weakness or fatigue (72.7% versus 42.3%) and patient-reported symptoms of generalized muscle weakness, malaise, and fatigue (69.0% versus 59.7%) (Table 2).

Compared with control patients, post–COVID-19 patients had higher prevalences of reported fair or poor general health (32.9% versus 25.4%), poorer physical health (44.1% versus 32.6%), pain level ≥7 (on a scale of 0–10) (40.4% versus 24.8%), and difficulty with physical activities (32.3% versus 24.2%) (Table 3). Post–COVID-19 patients also reported a higher prevalence of fair or poor overall mental health than control patients (19.1% versus 15.3%). Post–COVID-19 patients and control patients reported more challenges with applied cognition as indicated by T-scores (42.2 versus 41.2), both approximately one SD below the normative sample with which the scale was developed. Post–COVID-19 patients also demonstrated reduced physical endurance on the 6MWT compared with control patients (distance of 303 m versus 377 m; p<0.001) and reported increased difficulty completing chores (38.2% versus 25.2%), navigating stairs (40.2% versus 18.3%), running errands or shopping (34.3% versus 16.0%), and walking for 15 minutes (38.2% versus 16.6%). Compared with control patients, post–COVID-19 patients also reported more difficulty doing usual work or work at home (37.2% versus 20.4%) and challenges in ability to participate in activities with friends (33.0% versus 18.8%). For measures of health care use, post–COVID-19 patients required significantly more visits (median = 9, interquartile range [IQR] = 4–20) than control patients (median = 5, IQR 1–11; p<0.001) and longer therapy duration (median = 35 days, IQR = 15–71 days versus median = 27 days, IQR = 0–57 days; p<0.001).

*Data used were from Select Medical, a network of rehabilitation clinics in 36 states and the District of Columbia. https://www.selectmedical.com/
§ International Classification of Diseases, Tenth Revision codes used to examine potential post-COVID condition were J96.01, M62.81, R.26.2, R26.89 R53, R53.1, and R53.83.
PROMIS items use a Likert-type response scale (https://commonfund.nih.gov/promis/index). The 10 PROMIS items used in this analysis included overall self-rated health; overall quality of life; overall physical health; overall mental health; and individual items on fatigue, pain, emotional distress, and social activities and roles. Most questions asked about a person's experience "in general," with items on fatigue, pain, and emotional problems experienced during the past 7 days. Psychometric evaluation of the PROMIS global health items were based on two global physical health (GPH) and global mental health (GMH) scales. The PROMIS GPH scale included four items that rated overall physical health (physical functioning, physical activities, pain, and fatigue). GPH and GMH total raw scores were computed by summing item scores that ranged from 1 to 5, such that higher scores reflected better functioning and are then rescaled to a mean of 50 and an SD of 10 using nationally normative data from the U.S. general population. The estimated correlation between the GPH and GMH was 0.63.
**Neuro-QoL is a set of self-report measures that assesses the health-related quality of life of adults with neurologic disorders. Neuro-QoL AC-GC assesses perceived difficulties in everyday cognitive abilities, such as memory, attention, and decision-making. https://www.healthmeasures.net/explore-measurement-systems/neuro-qol
††Physical endurance was assessed using the 6-minute walk test. A poor 6-minute walk distance (e.g., <300 m) might have prognostic value (i.e., usually associated with an increased risk of mortality), and a change of 14.0 to 30.5 m might be clinically relevant.
§§Other demographic variables besides sex and age had substantial proportions of missing data (26%–75%); therefore, these variables were not included in the analysis.
¶¶45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. Sect. 241(d); 5 U.S.C. Sect. 552a; 44 U.S.C. Sect. 3501 et seq.