An Exploratory Factor Analysis of Long Covid

Abstract

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.

Comparing Frequency and Severity Ratings for ME/CFS versus Controls

“…Initially, patients with Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) had case definitions that only stipulated symptom occurrence. Unfortunately, many of the somatic symptoms among patients with this illness are relatively common, so there was a need to move beyond assessing symptoms by just measuring occurrence in order to better differentiate symptoms that are common but not a burden to the patients versus those that are a burden to patients [1]. This was achieved by measuring frequency rather than just occurrence of symptoms, as a highly frequent somatic symptom was considered to be more of a burden than one that occurred not frequently.…”