A systematic review of trials currently investigating therapeutic modalities for post-acute COVID-19 syndrome and registered on WHO International Clinical Trials Platform.

BACKGROUND: Post-acute COVID-19 syndrome (PACS) is a well-recognized, complex, systemic disease which is associated with substantial morbidity. There is a paucity of established interventions for the treatment of patients with this syndrome. OBJECTIVES: To systematically review registered trials currently investigating therapeutic modalities for PACS. DATA SOURCES: A search was conducted up to the 16 September, 2022, using the COVID-19 section of the WHO Internal Clinical Trials Registry Platform. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS: Interventional clinical trials of any sample size examining any therapeutic modality targeting persistent symptoms among individuals after diagnosis with COVID-19. METHODS: Data on trial characteristics and intervention characteristics were collected and summarized. RESULTS: After screening 17 125 trials, 388 trials, from 42 countries, were eligible. In total, we had 406 interventions, of which 368 were mono-therapeutic strategies, whereas 38 were intervention combinations. Among 824 primary outcomes identified, there were >300 different outcomes. Rehabilitation was the most employed class of intervention in 169 trials. We encountered 76 trials examining the pharmacological agents of various classes, with the most common agent being colchicine. Complementary and alternative medicine encompassed 64 trials exploring traditional Chinese medicine, Ayurveda, homeopathic medications, naturopathic medications, vitamins, dietary supplements, and botanicals. Psychotherapeutic and educational interventions were also employed in 12 and 4 trials, respectively. Other interventions, including transcranial direct current stimulation, transcutaneous auricular vagus nerve stimulation, general electrical stimulation, cranial electrotherapy stimulation, various stem cell interventions, and oxygen therapy interventions, were also employed. CONCLUSION: We identified 388 registered trials, with a high degree of heterogeneity, exploring 144 unique mono-therapeutic interventions for PACS. Most studies target general alleviation of symptoms. There is a need for further high-quality and methodologically robust PACS treatment trials to be conducted with standardization of outcomes while following WHO's recommendation for uniform evaluation and treatment.

Prevalence of post-acute COVID-19 syndrome symptoms at different follow-up periods: a systematic review and meta-analysis.

BACKGROUND: Post-acute coronavirus 2019 (COVID-19) syndrome is now recognized as a complex systemic disease that is associated with substantial morbidity. OBJECTIVES: To estimate the prevalence of persistent symptoms and signs at least 12 weeks after acute COVID-19 at different follow-up periods. DATA SOURCES: Searches were conducted up to October 2021 in Ovid Embase, Ovid Medline, and PubMed. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS: Articles in English that reported the prevalence of persistent symptoms among individuals with confirmed severe acute respiratory syndrome coronavirus 2 infection and included at least 50 patients with a follow-up of at least 12 weeks after acute illness. METHODS: Random-effect meta-analysis was performed to produce a pooled prevalence for each symptom at four different follow-up time intervals. Between-study heterogeneity was evaluated using the I2 statistic and was explored via meta-regression, considering several a priori study-level variables. Risk of bias was assessed using the Joanna Briggs Institute tool and the Newcastle-Ottawa Scale for prevalence studies and comparative studies, respectively. RESULTS: After screening 3209 studies, a total of 63 studies were eligible, with a total COVID-19 population of 257 348. The most commonly reported symptoms were fatigue, dyspnea, sleep disorder, and difficulty concentrating (32%, 25%, 24%, and 22%, respectively, at 3- to <6-month follow-up); effort intolerance, fatigue, sleep disorder, and dyspnea (45%, 36%, 29%, and 25%, respectively, at 6- to <9-month follow-up); fatigue (37%) and dyspnea (21%) at 9 to <12 months; and fatigue, dyspnea, sleep disorder, and myalgia (41%, 31%, 30%, and 22%, respectively, at >12-month follow-up). There was substantial between-study heterogeneity for all reported symptom prevalences. Meta-regressions identified statistically significant effect modifiers: world region, male sex, diabetes mellitus, disease severity, and overall study quality score. Five of six studies including a comparator group consisting of COVID-19-negative cases observed significant adjusted associations between COVID-19 and several long-term symptoms. CONCLUSIONS: This systematic review found that a large proportion of patients experience post-acute COVID-19 syndrome 3 to 12 months after recovery from the acute phase of COVID-19. However, available studies of post-acute COVID-19 syndrome are highly heterogeneous. Future studies need to have appropriate comparator groups, standardized symptom definitions and measurements, and longer follow-up.