Face masks while exercising trial (MERIT): a cross-over randomised controlled study.

OBJECTIVES: Physical exertion is a high-risk activity for aerosol emission of respiratory pathogens. We aimed to determine the safety and tolerability of healthy young adults wearing different types of face mask during moderate-to-high intensity exercise. DESIGN: Cross-over randomised controlled study, completed between June 2021 and January 2022. PARTICIPANTS: Volunteers aged 18-35 years, who exercised regularly and had no significant pre-existing health conditions. INTERVENTIONS: Comparison of wearing a surgical, cloth and filtering face piece (FFP3) mask to no mask during 4×15 min bouts of exercise. Exercise was running outdoors or indoor rowing at moderate-to-high intensity, with consistency of distance travelled between bouts confirmed using a smartphone application (Strava). Each participant completed each bout in random order. OUTCOMES: The primary outcome was change in oxygen saturations. Secondary outcomes were change in heart rate, perceived impact of face mask wearing during exercise and willingness to wear a face mask for future exercise. RESULTS: All 72 volunteers (mean age 23.9) completed the study. Changes in oxygen saturations did not exceed the prespecified non-inferiority margin (2% difference) with any mask type compared with no mask. At the end of exercise, the estimated average difference in oxygen saturations for cloth mask was -0.07% (95% CI -0.39% to 0.25%), for surgical 0.28% (-0.04% to 0.60%) and for FFP3 -0.21% (-0.53% to 0.11%). The corresponding estimated average difference in heart rate for cloth mask was -1.20 bpm (95% CI -4.56 to 2.15), for surgical 0.36 bpm (95% CI -3.01 to 3.73) and for FFP3 0.52 bpm (95% CI -2.85 to 3.89). Wearing a face mask caused additional symptoms such as breathlessness (n=13, 18%) and dizziness (n=7, 10%). 33 participants broadly supported face mask wearing during exercise, particularly indoors, but 22 were opposed. CONCLUSION: This study adds to previous findings (mostly from non-randomised studies) that exercising at moderate-to-high intensity wearing a face mask appears to be safe in healthy, young adults. TRIAL REGISTRATION NUMBER: NCT04932226.

The incidence of Kawasaki disease using hospital admissions data for England 2006-2021.

OBJECTIVE: To describe the incidence of Kawasaki Disease (kDa) between 2006 and 2021 in England. METHODS: We identified all cases in hospital episode statistics with an ICD-10 diagnostic code M303 (for kDa) between 1 April 2006 and 31 March 2021. We validated 83 diagnoses using hospital medical records and found >97% accuracy. We calculated incidence rate ratios (IRRs) using Poisson regression and assessed the influence of age, sex, ethnicity and index of multiple deprivation (IMD). We used Office for National Statistics population estimates for England as the denominator. RESULTS: We identified a total of 5908 cases of kDa in all children under the age of 16 (mean age 3.8, s.d.=3.2, 95% CI: 3.7, 3.9). Incidence in children aged <5 years was 8.9 (95% CI: 8.6, 9.2)/100 000 person-years; in children aged 5-9, 2.4 (95% CI: 2.3, 2.6)/100 000 person-years; and in children aged 10-15, 0.6 (95% CI: 0.6, 0.7). Male : female ratio was 1.5 : 1. Incidence was higher among non-White than White ethnicities [adjusted IRR 2.1 (2.0-2.2) for Asian, 3.0 (2.8-3.3) for Black and 4.5 (4.2-4.8) for other ethnicities]. The incidence increased with socioeconomic deprivation; the adjusted IRR of the least deprived IMD quintile compared with the most deprived quintile was 0.81 (0.77-0.84). CONCLUSIONS: Incidence rates of kDa derived from hospital admission data in England were higher than in studies relying on clinician reporting. We confirm previous findings on the influence of sex and ethnicity on kDa incidence and observe that there was a higher incidence of kDa within more deprived socioeconomic groups.

A systematic review and meta-analysis of the incidence rate of Takayasu arteritis.

OBJECTIVES: Takayasu arteritis (TAK) is a rare autoimmune rheumatic disease causing large-vessel vasculitis. Onset is typically between the ages of 20 and 30 years. It is associated with substantial morbidity and mortality, notably due to its effects on the cardiovascular system. It has a poorly understood global epidemiology. Our objective was to systematically review the available evidence in order to calculate the incidence rate of TAK. METHODS: Three databases (MEDLINE, PubMed and Embase) were searched in November 2019 and the results were screened by two reviewers. A random effects meta-analysis was then conducted in R to calculate the overall incidence rate. Heterogeneity was assessed using I2. The quality of the studies was assessed using an adapted Newcastle-Ottawa scale. Further subgroup analyses were performed by quality, sex, research setting and geographical location. Publication bias was assessed using a Begg's funnel plot. RESULTS: The incidence rate for TAK was 1.11 per million person-years (95% CI 0.70-1.76). The heterogeneity in the data was extremely high in all analyses, which suggests that there was considerable variation in incidence rates across the different populations studied. TAK was found to be more common in women (incidence rate 2.01 per million person-years, 95% CI 1.39-2.90). CONCLUSIONS: TAK is an extremely rare disease. It affects women more commonly than men. There is considerable variation in the incidence rate between populations. We suggest that future research should focus on discrete populations in order to better identify genetic and environmental risk factors.