Identifying people with post-COVID condition using linked, population-based administrative health data from Manitoba, Canada: prevalence and predictors in a cohort of COVID-positive individuals.

OBJECTIVE

Many individuals exposed to SARS-CoV-2 experience long-term symptoms as part of a syndrome called post-COVID condition (PCC). Research on PCC is still emerging but is urgently needed to support diagnosis, clinical treatment guidelines and health system resource allocation. In this study, we developed a method to identify PCC cases using administrative health data and report PCC prevalence and predictive factors in Manitoba, Canada.

DESIGN

Cohort study.

SETTING

Manitoba, Canada.

PARTICIPANTS

All Manitobans who tested positive for SARS-CoV-2 during population-wide PCR testing from March 2020 to December 2021 (n=66 365) and were subsequently deemed to have PCC based on International Classification of Disease-9/10 diagnostic codes and prescription drug codes (n=11 316). Additional PCC cases were identified using predictive modelling to assess patterns of health service use, including physician visits, emergency department visits and hospitalisation for any reason (n=4155).

OUTCOMES

We measured PCC prevalence as % PCC cases among Manitobans with positive tests and identified predictive factors associated with PCC by calculating odds ratios with 95% confidence intervals, adjusted for sociodemographic and clinical characteristics (aOR).

RESULTS

Among 66 365 Manitobans with positive tests, we identified 15 471 (23%) as having PCC. Being female (aOR 1.64, 95% CI 1.58 to 1.71), being age 60-79 (aOR 1.33, 95% CI 1.25 to 1.41) or age 80+ (aOR 1.62, 95% CI 1.46 to 1.80), being hospitalised within 14 days of COVID-19 infection (aOR 1.95, 95% CI 1.80 to 2.10) and having a Charlson Comorbidity Index of 1+ (aOR 1.95, 95% CI 1.78 to 2.14) were predictive of PCC. Receiving 1+ doses of the COVID-19 vaccine (one dose, aOR 0.80, 95% CI 0.74 to 0.86; two doses, aOR 0.29, 95% CI 0.22 to 0.31) decreased the odds of PCC.

CONCLUSIONS

This data-driven approach expands our understanding of the prevalence and epidemiology of PCC and may be applied in other jurisdictions with population-based data. The study provides additional insights into risk and protective factors for PCC to inform health system planning and service delivery.