Risk of new diagnoses and exacerbations of chronic conditions after SARS-CoV-2 infection: a systematic review update

The large number of people infected by SARS-CoV-2 necessitates estimation of the future health care burdens. We updated a systematic review examining associations between SARS-CoV-2 infection and incidence of new diagnoses and exacerbations of chronic conditions. Updated searches were run September 4, 2024, in the MEDLINE and Embase databases for observational studies with a control group, adjustment by sex and comorbid conditions, and reporting age-stratified data for 1 or more chronic condition category (n = 12) or condition type (n = 46) of interest. Two human reviewers screened 50% of titles and abstracts, then DistillerAI acted as second reviewer. Two human reviewers assessed full texts of relevant studies for eligibility based on a priori criteria. One reviewer extracted data and assessed risk of bias using the JBI cohort studies checklist; a second reviewer verified results data and risk-of-bias assessments. Pooled hazard ratios (HRs) were estimated with inverse-variance weighting. Using the Grading of Recommendations, Assessment, Development, and Evaluation approach, 2 reviewers assessed certainty in conclusions of little to no association (ie, HR = 0.75-1.25), small to moderate association (ie, HR = 0.51-0.74 or 1.26-1.99), or large association (ie, HR ≤ 0.50 or ≥ 2.00). We identified 46 new studies and brought forward 23 studies from the original review. After SARS-CoV-2 infection, there is probably increased risk of new diagnoses for several chronic conditions, especially in adults. Most findings are based on data from earlier pandemic periods; their relevance to contemporary populations is uncertain due to differences in vaccination rates and circulating variants of concern. PROSPERO registration identifier CRD42024585278.