Although most patients with COVID-19 recover within a few weeks, a subset of patients experience ongoing symptoms, a condition referred to as long COVID or post-COVID-19 condition (PCC). A case-control study based on a health insurance claims database was conducted to assess 12-month outcomes in a cohort of people with PCC compared with a propensity-matched comparison group who had similar baseline characteristics.

The study sample comprised 13,435 adults with PCC and 26,870 matched adults who hadn't had COVID. Participants with PCC had a relatively high level of chronic conditions before they had COVID.

The PCC cohort had a consistent elevation in adverse outcomes compared with the control group. During follow-up, the PCC cohort had increased health care utilization for cardiac arrhythmias, pulmonary embolism, ischemic stroke, coronary artery disease, heart failure, chronic obstructive pulmonary disease, and asthma. The PCC cohort also had increased mortality compared with the control group (2.8% versus 1.2%), implying an excess death rate of 16.4 per 1,000 individuals.

The study used claims data, which provide information about people who've received care, so those who self-managed their symptoms were excluded. In addition, the study period predates the availability of vaccines, which may limit the generalizability of the results.

The authors conclude that it will be crucial for clinicians to assess the ongoing needs of patients with PCC, especially regarding the onset of chronic conditions following the initial COVID-19 illness.