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Personal protective effect of wearing surgical face masks in public spaces on self-reported respiratory symptoms in adults: pragmatic randomised superiority trial

Author/s: 
Runar Barstad Solberg, Atle Fretheim, Ingeborg Hess Elgersma, Mette Fagernes, Bjørn Gunnar Iversen, Lars G Hemkens, Christopher James Rose, Petter Elstrøm

Objective: To evaluate the personal protective effects of wearing versus not wearing surgical face masks in public spaces on self-reported respiratory symptoms over a 14 day period.

Design: Pragmatic randomised superiority trial.

Setting: Norway.

Participants: 4647 adults aged ≥18 years: 2371 were assigned to the intervention arm and 2276 to the control arm.

Interventions: Participants in the intervention arm were assigned to wear a surgical face mask in public spaces (eg, shopping centres, streets, public transport) over a 14 day period (mask wearing at home or work was not mentioned). Participants in the control arm were assigned to not wear a surgical face mask in public places.

Main outcome measures: The primary outcome was self-reported respiratory symptoms consistent with a respiratory infection. Secondary outcomes included self-reported and registered covid-19 infection.

Results: Between 10 February 2023 and 27 April 2023, 4647 participants were randomised of whom 4575 (2788 women (60.9%); mean age 51.0 (standard deviation 15.0) years) were included in the intention-to-treat analysis: 2313 (50.6%) in the intervention arm and 2262 (49.4%) in the control arm. 163 events (8.9%) of self-reported symptoms consistent with respiratory infection were reported in the intervention arm and 239 (12.2%) in the control arm. The marginal odds ratio was 0.71 (95% confidence interval (CI) 0.58 to 0.87; P=0.001) favouring the face mask intervention. The absolute risk difference was -3.2% (95% CI -5.2% to -1.3%; P<0.001). No statistically significant effect was found on self- reported (marginal odds ratio 1.07, 95% CI 0.58 to 1.98; P=0.82) or registered covid-19 infection (effect estimate and 95% CI not estimable owing to lack of events in the intervention arm).

Conclusion: Wearing a surgical face mask in public spaces over 14 days reduces the risk of self-reported symptoms consistent with a respiratory infection, compared with not wearing a surgical face mask.

Trial registration: ClinicalTrials.gov NCT05690516.

Keywords 
Betacoronavirus COVID-19 masks face masks respiratory tract infections

Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis.

Author/s: 
Martineau, Adrian R., Jolliffe, David A., Greenberg, Lauren, Aloia, John F., Bergman, Peter, Dubnov-Rax, Gal, Esposito, Susanna, Ganmaa, Davaasambuu, Ginde, Adit A., Goodall, Emma C., Grant, Cameron C., Janssens, Wim, Jensen, Megan E., Kerley, Conor P., Laaksi, Ilkka, Manaseki-Holland, Semira, Mauger, David, Murdoch, David R., Neale, Rachel, Rees, Judy R., Simpson, Steve Jr., Stelmach, Iwona, Kumar, Geeta Trilok, Mitsuyoshi, Urashima, Camargo, Carlos A. Jr., Griffiths, Christopher J., Hooper, Richard L.

BACKGROUND:

Randomised controlled trials (RCTs) exploring the potential of vitamin D to prevent acuterespiratory infections have yielded mixed results. Individual participant data (IPD) meta-analysis has the potential to identify factors that may explain this heterogeneity.

OBJECTIVES:

To assess the overall effect of vitamin D supplementation on the risk of acute respiratory infections (ARIs) and to identify factors modifying this effect.

DATA SOURCES:

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, ClinicalTrials.gov and the International Standard Randomised Controlled Trials Number (ISRCTN) registry.

STUDY SELECTION:

Randomised, double-blind, placebo-controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration having incidence of acute respiratory infection as a prespecified efficacy outcome were selected.

STUDY APPRAISAL:

Study quality was assessed using the Cochrane Collaboration Risk of Bias tool to assess sequence generation, allocation concealment, blinding of participants, personnel and outcome assessors, completeness of outcome data, evidence of selective outcome reporting and other potential threats to validity.

RESULTS:

We identified 25 eligible RCTs (a total of 11,321 participants, aged from 0 to 95 years). IPD were obtained for 10,933 out of 11,321 (96.6%) participants. Vitamin D supplementation reduced the risk of ARI among all participants [adjusted odds ratio (aOR) 0.88, 95% confidence interval (CI) 0.81 to 0.96; heterogeneity p < 0.001]. Subgroup analysis revealed that protective effects were seen in individuals receiving daily or weekly vitamin D without additional bolus doses (aOR 0.81, 95% CI 0.72 to 0.91), but not in those receiving one or more bolus doses (aOR 0.97, 95% CI 0.86 to 1.10; p = 0.05). Among those receiving daily or weekly vitamin D, protective effects of vitamin D were stronger in individuals with a baseline 25-hydroxyvitamin D [25(OH)D] concentration of < 25 nmol/l (aOR 0.30, 95% CI 0.17 to 0.53) than in those with a baseline 25(OH)D concentration of ≥ 25 nmol/l (aOR 0.75, 95% CI 0.60 to 0.95; p = 0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (aOR 0.98, 95% CI 0.80 to 1.20; p = 0.83). The body of evidence contributing to these analyses was assessed as being of high quality.

LIMITATIONS:

Our study had limited power to detect the effects of vitamin D supplementation on the risk of upper versus lower respiratory infection, analysed separately.

CONCLUSIONS:

Vitamin D supplementation was safe, and it protected against ARIs overall. Very deficient individuals and those not receiving bolus doses experienced the benefit. Incorporation of additional IPD from ongoing trials in the field has the potential to increase statistical power for analyses of secondary outcomes.

Keywords 
vitamin D dietary supplements respiratory infections

Intermittent Inhaled Corticosteroids and Long-Acting Muscarinic Antagonists for Asthma

Author/s: 
Sobieraj, Diana M., Baker, William L., Weeda, Erin R., Nguyen, Elaine, Coleman, Craig I., White, C. Michael, Lazarus, Stephen C., Blake, Kathryn V., Lang, Jason E.

Objective. To assess efficacy of intermittent inhaled corticosteroid (ICS) therapy in different populations (0 to 4 years old with recurrent wheezing, 5 years and older with persistent asthma, with or without long-acting beta agonist [LABA]), and to assess efficacy of added long-acting muscarinic antagonist (LAMA) in patients 12 years and older with uncontrolled, persistent asthma.

Data sources. MEDLINE®, Embase®, Cochrane Central, and Cochrane Database of Systematic Reviews bibliographic databases from earliest date through March 23, 2017; hand searches of references of relevant studies; www.clinicaltrials.gov and the International Controlled Trials Registry Platform.

Review methods. Two investigators screened abstracts of identified references for eligibility and subsequently reviewed full-text files. We abstracted data, performed meta-analyses when appropriate, assessed the risk of bias of each individual study, and graded the strength of evidence for each comparison and outcome. Outcomes for which data were extracted included exacerbations, mortality, asthma control composite scores, spirometry, asthma-specific quality of life, and rescue medication use.

Results. We included 56 unique studies (54 randomized controlled trials, 2 observational studies) in this review. Compared to rescue short-acting beta-agonist (SABA) use, adding intermittent ICS reduces the risk of exacerbation requiring oral steroids and improves caregiver quality of life in children less than 5 years old with recurrent wheezing in the setting of a respiratory tract infection (RTI). In patients 12 years and older with persistent asthma, differences in intermittent ICS versus controller use of ICS were not detected, although few studies provided evidence, leading to primarily low strength of evidence ratings. Using ICS and LABA as both a controller and quick relief therapy reduced the risk of exacerbations and improved symptom control in patients 12 years and older compared to ICS controller (with or without LABA). Data in patients 4 to 11 years old suggest lower risk of exacerbations with ICS and LABA controller and quick relief use, but with a lower strength of evidence than in the older population. In patients 12 years and older with uncontrolled, persistent asthma, LAMA versus placebo as add-on to ICS reduces the risk of exacerbations requiring systemic corticosteroids and improves lung function measure through spirometry. Current evidence does not suggest that a difference exists in the efficacy of LAMA versus LABA as add-on to ICS. Triple therapy of ICS, LAMA, and LABA improves lung function measured through spirometry, although the risk of exacerbation was not different versus ICS and LABA.

Conclusions. Intermittent ICS added to SABA during an RTI provides benefit to patients less than 5 years of age with recurrent wheezing. In patients 12 years and older with persistent asthma, differences in intermittent ICS versus controller use of ICS were not detected, although few studies provided evidence for this question. In patients 12 years and older with persistent asthma, using ICS and LABA as both a controller and quick relief therapy may be more effective at preventing exacerbations than ICS controller (with or without LABA). LAMA is effective in the management of uncontrolled, persistent asthma in patients 12 years of age and older, and current evidence does not suggest a difference between LAMA and LABA as add-on to ICS.

Keywords 
asthma musacarinic antagonist corticosteroids
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