Prevalence of long-term effects in individuals diagnosed with COVID-19: an updated living systematic review

Abstract

Background: Patients have described symptoms persisting or recurring for weeks after acute COVID-19 illness referred to as post COVID-19 conditions. The objective of this living systematic review is to document the prevalence of post COVID-19 conditions 4-12 weeks (short-term) and >12 weeks (long-term) after COVID-19 diagnosis. Methods: We conducted a systematic review of primary peer-reviewed published literature reporting on the prevalence of the symptoms, sequelae and difficulties conducting usual activities ≥4 weeks after COVID-19 diagnosis. We adapted a previous search strategy used by the U.K. National Institute for Health and Care Excellence and updated it to search for new research published until January 15, 2021 in Embase, Medline, PsychInfo, and Cochrane Central. Two independent reviewers screened references; one reviewer extracted data and assessed risk of bias and certainty in the evidence while another verified them. Prevalence data from laboratory-confirmed individuals were meta-analyzed, where appropriate, using a random effects model and synthesized separately in the short- and long-term periods after COVID-19 diagnosis; data from clinically-diagnosed populations were synthesized narratively. Results: Of the 2807 unique citations, 36 observational studies met our inclusion criteria. Over 100 post COVID-19 conditions were reported in laboratory-confirmed individuals. Eighty-three percent (95%CI: 65-93%; low certainty) and 56% (95%CI: 34-75%; very low certainty) reported persistence or presence of one or more symptoms in the short- and long-term, respectively. The most prevalent symptoms in both periods included: fatigue, general pain or discomfort, sleep disturbances, shortness of breath and anxiety or depression (point estimates ranging from 22-51%; low to very low certainty). Interpretation: Our data indicate that a substantial proportion of individuals reported a variety of symptoms ≥4 weeks after COVID-19 diagnosis. Due to low certainty in the evidence, further research is needed to determine the true burden of post COVID-19 conditions.

Clinical coding of long COVID in English primary care: a federated analysis of 58 million patient records in situ using OpenSAFELY

“…A recent systematic review found a very high prevalence of persisting COVID symptoms after COVID diagnosis 2 . For symptoms lasting 4-12 weeks 83% of people reported at least one persisting symptom, while for symptoms lasting beyond 12 weeks, the proportion was 56%.…”

An Overview of Post–COVID-19 Condition (Long COVID)

“…Evidence from a preprint systematic review 23 suggests that 83% of people with confirmed COVID-19 may experience 1 or more symptoms after 4 to 12 weeks of their infections. These symptoms may include body and muscle aches, dyspnea (i.e., shortness of breath) or breathing difficulties, and weakness or fatigue, which have been reported by multiple studies.…”

“…These symptoms may include body and muscle aches, dyspnea (i.e., shortness of breath) or breathing difficulties, and weakness or fatigue, which have been reported by multiple studies. 21,[23][24][25][26][27][28][29] After 12 weeks, the systematic review reported that 56% of people may experience 1 or more symptoms, with fatigue being 1 of the most common symptoms and experienced by nearly half of people (47%). 23 Other new or persisting symptoms after 12 weeks include breathing difficulties or shortness of breath, post-exertional malaise (worsening of symptoms after physical or mental activity), cognitive dysfunction, reduced exercise capacity, and loss of taste and/or smell.…”

“…21,[23][24][25][26][27][28][29] After 12 weeks, the systematic review reported that 56% of people may experience 1 or more symptoms, with fatigue being 1 of the most common symptoms and experienced by nearly half of people (47%). 23 Other new or persisting symptoms after 12 weeks include breathing difficulties or shortness of breath, post-exertional malaise (worsening of symptoms after physical or mental activity), cognitive dysfunction, reduced exercise capacity, and loss of taste and/or smell. 22,[30][31][32][33][34] The preprint systematic review noted that there is relatively little research examining the prevalence of symptoms after 12 weeks and that many studies have limited sample sizes (fewer than 200 people) and are often without comparison groups, increasing the risk of bias.…”

“…22,[30][31][32][33][34] The preprint systematic review noted that there is relatively little research examining the prevalence of symptoms after 12 weeks and that many studies have limited sample sizes (fewer than 200 people) and are often without comparison groups, increasing the risk of bias. 23 Without comparatives, studies are limited in attributing the reported symptoms specifically to post-COVID-19, as other pre-existing health conditions and factors may also be contributing to symptom occurrence. There may be differences by age, sex, and other factors, and symptoms may change over time, all of which warrants more in-depth and longer-term research.…”