Self-reported symptom severity, general health, and impairment in post-acute phases of COVID-19: retrospective cohort study of Swedish public employees

Abstract

This study aimed to examine current symptom severity and general health in a sample of primarily non-hospitalized persons with polymerase chain reaction (PCR) confirmed COVID-19 in comparison to PCR negative controls. During the first quarter of 2021, we conducted an online survey among public employees in West Sweden, with a valid COVID-19 test result. The survey assessed past-month severity of 28 symptoms and signs, self-rated health, the WHO Disability Assessment Schedule (WHODAS) 2.0 and illness severity at the time of test. We linked participants' responses to their SARS-CoV-2 PCR tests results. We compared COVID-19 positive and negative participants using univariable and multivariable regression analyses. Out of 56,221 invited, 14,222 (25.3%) responded, with a response rate of 50% among SARS-CoV-2 positive individuals. Analysis included 10,194 participants (86.4% women, mean age 45 years) who tested positive 4-12 weeks (N = 1425; subacute) and > 12 weeks (N = 1584; postcovid) prior to the survey, and 7185 PCR negative participants who did not believe that they had had COVID-19. Symptoms were highly prevalent in all groups, with worst symptoms in subacute phase participants, followed by postcovid phase and PCR negative participants. The most specific symptom for COVID-19 was loss of smell or taste. Both WHODAS 2.0 score and self-rated health were worst in subacute participants, and modestly worse in postcovid participants than in negative controls. Female gender, older age and acute illness severity had larger effects on self-rated health and WHODAS 2.0 score in PCR positive participants than in PCR negative. Studies with longer follow-up are needed to determine the long-term improvement after COVID-19.

Figure 1

Flowchart of the study sample.

Figure 2

Symptoms and signs as reported by study participants according to subgroup. Left panel: Proportion with each severity level of symptoms and signs among study participants [(1) Subacute phase, (2) postcovid phase, (3) PCR negative]. Right panel: Odds ratio of higher severity of each symptom and sign in SARS-CoV-2 positive in the subacute (blue, > 4 weeks and ≤ 12 weeks from positive PCR) and postcovid (green, > 12 weeks from positive PCR) phase compared to PCR negative participants (red, reference category). Odds ratios are from univariable ordinal logistic regression analyses. The scale is logarithmic.

Figure 3

Distribution of WHODAS sum scores according to COVID-19 status. (A) Density plot of WHODAS 2.0 sum scores (range 0–48). Vertical axis presents proportion of participants with each WHODAS score (horizontal axis). Vertical lines represent means of PCR negative participants (red; mean 3.1), postcovid (green, mean 4.3) and subacute groups (blue, mean 6.2). (B) Proportions in each category of self-rated health, from very bad to very good, left to right: PCR subacute phase, postcovid phase and  negative.

Figure 4

Distribution of WHODAS 2.0 score and rating of self-rated health between subgroups. (A) Mean WHODAS 2.0 scores with 95% confidence intervals (left panel) and mean ratio of WHODAS 2.0 scores (right panel, estimated from univariable negative binomial regression analyses) in subgroups where there was a significant interaction between the variable of interest and COVID-19 status on the effect of WHODAS 2.0. (B) Proportions of ratings of self-rated health (left panel) and odds ratios for worse self-rated health (right panel, estimated with univariable ordinal logistic regression) in subgroups where there was a significant interaction between the variable of interest and COVID-19 status on the effect of self-rated health.