Post by Nadica (She/Her) on Jul 16, 2024 19:52:31 GMT
Allergic diseases as risk factors for Long-COVID symptoms: Systematic review of prospective cohort studies - Published Nov 8, 2023
Abstract
Objective
The role of allergy as a risk factor for Long-COVID (LC) is unclear and has not been thoroughly examined yet. We aimed to systematically review and appraise the epidemiological evidence on allergic diseases as risk factors for LC.
Design
This is an initial systematic review. Two reviewers independently performed the study selection and data extraction using Covidence. Risk of bias (RoB) and certainty of evidence (GRADE) were assessed. Random effects meta-analyses were used to pool unadjusted ORs within homogeneous data subsets.
Data Sources
We retrieved articles published between January 1st, 2020 and January 19th, 2023 from MEDLINE via PubMed, Scopus, the WHO-COVID-19 database and the LOVE platform (Epistemonikos Foundation). In addition, citations and reference lists were searched.
Eligibility Criteria
We included prospective cohort studies recruiting individuals of all ages with confirmed SARS-CoV-2 infection that were followed up for at least 12 months for LC symptoms where information on pre-existing allergic diseases was available. We excluded all study designs that were not prospective cohort studies and all publication types that were not original articles.
Results
We identified 13 studies (9967 participants, range 39–1950 per study), all assessed as high RoB, due to population selection and methods used to ascertain the exposures and the outcome. Four studies did not provide sufficient data to calculate Odds Ratios. The evidence supported a possible relationship between LC and allergy, but was very uncertain. For example, pre-existing asthma measured in hospital-based populations (6 studies, 4019 participants) may be associated with increased risk of LC (Odds Ratio 1.94, 95% CI 1.08, 3.50) and findings were similar for pre-existing rhinitis (3 studies, 1141 participants; Odds Ratio 1.96, 95% CI 1.61, 2.39), both very low certainty evidence.
Conclusions
Pre-existing asthma or rhinitis may increase the risk of LC.
Key Message
-In 13 included studies, the proportion of people with LC ranged from 11% to 90%.
-Pre-existing asthma measured in a hospital-based population and pre-existing rhinitis was associated with increased risk of LC.
-Evidence was of very low certainty, related to population selection and exposure and outcome measurements.
Graphical Abstract
We systematically reviewed and appraised the epidemiological evidence on allergic diseases as risk factors for Long-COVID. Meta-analysis revealed that pre-existing asthma measured in hospital-based populations and pre-existing rhinitis were significantly associated with increased Long-COVID incidences. Asthma and rhinitis may increase the risk of Long-COVID but the certainty of evidence is very low. CI, confidence interval; OR, odds ratio
Abstract
Objective
The role of allergy as a risk factor for Long-COVID (LC) is unclear and has not been thoroughly examined yet. We aimed to systematically review and appraise the epidemiological evidence on allergic diseases as risk factors for LC.
Design
This is an initial systematic review. Two reviewers independently performed the study selection and data extraction using Covidence. Risk of bias (RoB) and certainty of evidence (GRADE) were assessed. Random effects meta-analyses were used to pool unadjusted ORs within homogeneous data subsets.
Data Sources
We retrieved articles published between January 1st, 2020 and January 19th, 2023 from MEDLINE via PubMed, Scopus, the WHO-COVID-19 database and the LOVE platform (Epistemonikos Foundation). In addition, citations and reference lists were searched.
Eligibility Criteria
We included prospective cohort studies recruiting individuals of all ages with confirmed SARS-CoV-2 infection that were followed up for at least 12 months for LC symptoms where information on pre-existing allergic diseases was available. We excluded all study designs that were not prospective cohort studies and all publication types that were not original articles.
Results
We identified 13 studies (9967 participants, range 39–1950 per study), all assessed as high RoB, due to population selection and methods used to ascertain the exposures and the outcome. Four studies did not provide sufficient data to calculate Odds Ratios. The evidence supported a possible relationship between LC and allergy, but was very uncertain. For example, pre-existing asthma measured in hospital-based populations (6 studies, 4019 participants) may be associated with increased risk of LC (Odds Ratio 1.94, 95% CI 1.08, 3.50) and findings were similar for pre-existing rhinitis (3 studies, 1141 participants; Odds Ratio 1.96, 95% CI 1.61, 2.39), both very low certainty evidence.
Conclusions
Pre-existing asthma or rhinitis may increase the risk of LC.
Key Message
-In 13 included studies, the proportion of people with LC ranged from 11% to 90%.
-Pre-existing asthma measured in a hospital-based population and pre-existing rhinitis was associated with increased risk of LC.
-Evidence was of very low certainty, related to population selection and exposure and outcome measurements.
Graphical Abstract
We systematically reviewed and appraised the epidemiological evidence on allergic diseases as risk factors for Long-COVID. Meta-analysis revealed that pre-existing asthma measured in hospital-based populations and pre-existing rhinitis were significantly associated with increased Long-COVID incidences. Asthma and rhinitis may increase the risk of Long-COVID but the certainty of evidence is very low. CI, confidence interval; OR, odds ratio