Factors associated with the development, severity, and resolution of post COVID-19 condition in adults living in Canada, January 2020 to August 2022.

OBJECTIVES

We aimed to characterize the burden of post COVID-19 condition (PCC) among adults in Canada and identify factors associated with its occurrence, severity, and resolution.

METHODS

We used self-report data from a population-based cross-sectional probability survey of adults in Canada conducted between April and August 2022. Incidence and prevalence of PCC were estimated using confirmed infections, as well as confirmed and suspected combined. Multivariable modeling using confirmed cases identified associated factors.

RESULTS

As of August 2022, 17.2% (95% CI 15.7, 18.8) of adults with confirmed infections and 16.7% (95% CI 15.5, 18.0) of adults with confirmed or suspected infections experienced PCC, translating to 3.3% (95% CI 3.0, 3.6) and 4.4% (95% CI 4.1, 4.8) of all adults, respectively. Age less than 65 years (aORs of 1.75 to 2.14), more pre-existing comorbidities (aORs of 1.75 to 3.57), and a more severe initial infection (aORs of 3.52 to 9.69) were all associated with higher odds of PCC, while male sex at birth (aOR = 0.54, 95% CI 0.41, 0.70), identifying as Black (aOR = 0.23, 95% CI 0.11, 0.51), and being infected after 2020 (aORs of 0.24 to 0.55) were associated with lower odds. Those residing in a rural area (aOR = 2.31, 95% CI 1.35, 3.93), or reporting a disability (aOR = 2.87, 95% CI 1.14, 7.25), pre-existing chronic lung condition (aOR = 5.47, 95% CI 1.85, 16.12) or back problem (aOR = 2.34, 95% CI 1.26, 4.36), or PCC headache (aOR = 2.47, 95% CI 1.60, 3.83) or weakness (aOR = 2.27, 95% CI 1.41, 3.68) had higher odds of greater limitations in daily activities, while males had lower odds (aOR = 0.54, 95% CI 0.34, 0.85). Two or more pre-existing chronic conditions (aHRs from 0.33 to 0.38), or PCC symptoms relating to the heart (aHR = 0.25, 95% CI 0.07, 0.90), brain fog (aHR = 0.44, 95% CI 0.23, 0.86), or stress/anxiety (aHR = 0.48, 95% CI 0.24, 0.96) were associated with a decreased rate of symptom resolution.

CONCLUSION

Over the first two and a half years of the pandemic, a substantial proportion of infected adults in Canada reported PCC. Females and people with comorbidities were disproportionately impacted.