Factors associated with reduction in quality of life after SARS-CoV-2 infection.

Long-term changes in health-related quality of life (HrQoL) after SARS-CoV-2 infection are common, but their causes and consequences are poorly understood. This prospective, population-based study examined associations between HrQoL and 49 demographic and clinical variables. HrQoL was assessed using the European Quality-of-Life-5-Dimensions-5-Level-Version in 3,475 participants (56% female; aged 18-88 years) approximately 9 months (baseline) and 26 months (follow-up) after their initial infection. Results were compared with the demographic and clinical variables using recursive feature elimination and random forest regression analyses. A statistically significant improvement in HrQoL was observed during the observation period. At baseline, 39% of the variance in HrQoL was explained by fatigue, muscle pain, number of remaining symptoms (RS), perceived stress, and age. At follow-up, fatigue, RS, perceived stress, muscle and joint pain, and age explained 54% of the variance in HrQoL. Changes in HrQoL were associated with changes in fatigue, RS, and perceived stress, meaning that if these decreased from baseline to follow-up, then HrQoL was improved. However, it was not possible to predict whether an individual's HrQoL would improve or worsen 1 year later based on baseline variable scores. The aforementioned symptoms are specifically associated with impairment in the population's usual activities.