Jason Leonard

An exploratory factor analysis (EFA) can provide a window into the latent dimensions of a disease, such as Long COVID. Discovering the latent factors of Long COVID enables researchers and clinicians to better conceptualize, study and treat this disease. In this study, participants were recruited from social media sites dedicated to COVID and Long COVID. Among the 480 participants, those who completed at least 90% of the survey, reported symptoms for two or more months since COVID-19 symptom onset, and had not been hospitalized for COVID were used in the EFA. The mean duration since initial symptom onset was 74.0 (37.3) weeks. A new questionnaire called The DePaul Symptom Questionnaire-COVID was used to assess self-reports of the frequency and severity of 38 Long COVID symptoms experienced over the most recent month. The most burdensome symptoms were “Symptoms that get worse after physical or mental activities (also known as Post-Exertional Malaise),” “Fatigue/extreme tiredness,” “Difficulty thinking and/or concentrating,” “Sleep problems,” and “Muscle aches.” The EFA resulted in a three-factor model with factors labeled General, PEM/Fatigue/Cognitive Dysfunction, and Psychological, consisting of 16, 6, and 3 items respectively (25 items in total). The reliability of the items in the EFA was.90 using a split-half reliability test. Finally, participant self-reported level of functional impairment was analyzed across the three EFA factors. Interpretations and applications to research and practice are provided.

This study aimed to contribute to the development of a research case definition for post-acute sequelae of SARS CoV-2 infection using a PASC data set and experiences from case definitions developed for myalgic encephalomyelitis/chronic fatigue syndrome. Our database included patients with PASC who provided self-report symptomology during the onset of infection and the time of survey completion. We found that we could distinguish between those with mild, moderate, and severe PASC. Regarding the proportion meeting an ME/CFS case definition, we found 0% in the mildly impaired group, 30.6% to 62.6% in the moderately impaired group, and 74.3% to 89.0% in the severely impaired group. Based on these preliminary data, we propose a 5-part classification system for PASC. Axis 1 involves the variant of the COVID infection and the type of documentation of the infection. Axis 2 involves the time elapsed since infection. Axis 3 involves the type of medical collateral damage to different organs. Axis 4 involves functional impairment classified into three categories: mild, moderate, or severe. Finally, Axis 5 is the identified symptoms. Finally, if the patient has been sick for 6 or more months, it is important to determine whether the person has met the ME/CFS criteria. This proposed 5-part classification system for PASC might bring considerable clarity to diagnosing PASC.