Discussion
In our study, the overall prevalence of fatigue persistence among the COVID survivors was 62.9%. Townsend et al. reported that more than half of COVID-19 survivors reported fatigue, even after ten weeks later, regardless of their initial infection’s seriousness (Townsend et al., 2020). In another study, fatigue (55%) was the most common reported symptom among post-COVID patients who recovered from acute illness (Garrigues et al., 2020). The Italian study by Carfi et al. (2020) also had a similar result, with 53% (143 COVID-19 patients) reporting fatigue after a mean of 60 days of the first COVID-19 symptom. Locally, in a study conducted among physicians at Dhaka Medical College Hospital, fatigue level was found to be higher among SARS-CoV-2 infected individuals compared to control group. But, interestingly, no association could be established between fatigue and pre-existing co-morbidities, which are in stark contrast to our findings (Hasan et al., 2020). Another study conducted at same institution among post-COVID patients after one month, found 70% of study participants to be suffering from some form of fatigue (Mahmud et al., 2021).
On binary logistic regression, negative association was found between age and fatigue level. While the older age group is vulnerable to post-COVID complications, younger age groups are not immune to after effects of COVID-19. In a prospective Norwegian study, 21% of young people aged 16-30, isolating at home were still suffering from fatigue 6-months after their initial infection (Blomberg et al., 2021). Hence, while the association between age and fatigue level needs to be further evaluated, young people, contrary to popular belief, are highly susceptible to post-COVID complications like fatigue.
Statistically significant association was found between fatigue level and diabetes mellitus, on admission SpO2, hypertension, and ischemic heart disease. Previous studies indicate, diabetes mellitus and cardiac functioning status are common and independent predictors of fatigue among affected individuals (Kalra & Sahay, 2018; Fritschi & Quinn, 2010; Nelesen et al., 2008). Hence, our study findings perfectly complement previous researches on fatigue and its associated variables.
Among clinical and laboratory markers, fatigue was statistically associated with on admission SpO2, Hb%, serum ferritin, d-dimer, and CRP level. The relationship between Hb% and fatigue is previously documented in numerous studies where patients with lower Hb% tend to suffer from higher fatigue level (Holzner et al., 2002; Jacobsen et al., 2004). CRP, d-dimer, and serum ferritin are markers of acute infection in COVID-19 and previous studies indicate towards a strong association among these biomarkers and prevalence of fatigue (Vaucher et al., 2012; Cho et al., 2009; Townsend et al., 2021).