Effect of School Integrated Pest Management or Classroom Air Filter Purifiers on Asthma Symptoms in Students With Active Asthma

Abstract

for the School Inner-City Asthma Intervention study team IMPORTANCE School and classroom allergens and particles are associated with asthma morbidity, but the benefit of environmental remediation is not known. OBJECTIVE To determine whether use of a school-wide integrated pest management (IPM) program or high-efficiency particulate air (HEPA) filter purifiers in the classrooms improve asthma symptoms in students with active asthma.DESIGN, SETTING, AND PARTICIPANTS Factorial randomized clinical trial of a school-wide IPM program and HEPA filter purifiers in the classrooms was conducted from 2015 to 2020 (School Inner-City Asthma Intervention Study). There were 236 students with active asthma attending 41 participating urban elementary schools located in the Northeastern US who were randomized to IPM by school and HEPA filter purifiers by classroom. The date of final follow-up was June 20, 2020. INTERVENTIONSThe school-wide IPM program consisted of application of rodenticide, sealing entry points, trap placement, targeted cleaning, and brief educational handouts for school staff. Infestation was assessed every 3 months, with additional treatments as needed. Control schools received no IPM, cleaning, or education. Classroom portable HEPA filter purifiers were deployed and the filters were changed every 3 months. Control classrooms received sham HEPA filters that looked and sounded like active HEPA filter purifiers. Randomization was done independently (split-plot design), with matching by the number of enrolled students to ensure a nearly exact 1:1 student ratio for each intervention with 118 students randomized to each group. Participants, investigators, and those assessing outcomes were blinded to the interventions. MAIN OUTCOMES AND MEASURESThe primary outcome was the number of symptom-days with asthma during a 2-week period. Symptom-days were assessed every 2 months during the 10 months after randomization. RESULTS Among the 236 students who were randomized (mean age, 8.1 [SD, 2.0] years; 113 [48%] female), all completed the trial. At baseline, the 2-week mean was 2.2 (SD, 3.9) symptom-days with asthma and 98% of the classrooms had detectable levels of mouse allergen. The results were pooled because there was no statistically significant difference between the 2 interventions (P = .18 for interaction). During a 2-week period, the mean was 1.5 symptom-days with asthma after use of the school-wide IPM program vs 1.9 symptom-days after no IPM across the school year (incidence rate ratio, 0.71 [95% CI, 0.38-1.33]), which was not statistically significantly different. During a 2-week period, the mean was 1.6 symptom-days with asthma after use of HEPA filter purifiers in the classrooms vs 1.8 symptom-days after use of sham HEPA filter purifiers across the school year (incidence rate ratio, 1.47 [95% CI, 0.79-2.75]), which was not statistically significantly different. There were no intervention-related adverse events.CONCLUSIONS AND RELEVANCE Among children with active asthma, use of a school-wide IPM program or class...

Update on indoor allergens and their impact on pediatric asthma

“…In a 2021 study of classrooms in the inner-city northeast, 98% contained detectable mouse allergen. 33 In an earlier study, by Sheehan et al, 34 mouse allergen was detected in 99% of school dust samples, and levels of mouse allergen in schools were significantly higher than in students' homes (median settled dust level, 0.90 vs 0.14 mg/g; P < .001).…”

“…The authors postulate that combined reduction of both allergic and irritant triggers of asthma limited the susceptibility to viral-induced wheeze that is common during the fall and winter seasons. 33 The interplay between indoor allergens, irritants, and viral infections complicates the study of the impact on indoor allergens on asthma morbidity. Multifaceted interventions reducing all of these triggers are more likely to be successful.…”

The role of environmental allergen control in the management of asthma

“…Further work to sustain benefit and comprehensively support improvements in home, school, and other environments, while costly, may be needed. 67…”

Environmental Interventions for Asthma

“…[165][166][167][168][169][170] More recently, work in the schools to determine the effectiveness of a school and classroom-based environmental intervention to reduce asthma morbidity was recently reported by the School Inner-City Asthma Intervention Study (SICAS-2). 171 In the SICAS-2 study, an NIH/NIAID randomized clinical trial which examined the effect of school-wide IPM or classroom high-efficiency particulate air filter purifiers on asthma symptoms in students with active asthma, 236 children with asthma from 41 schools who lived in inner-city neighborhoods were included, with validated classroom interventions to decrease allergen environment content, IPM (reapplied every 3 months as needed), and HEPA filter purifiers used. Measurements of allergen content and exposure (dust and airborne) were collected in classroom samples at baseline and post-intervention, in addition to similar assessments of dust collections from the subjects' homes.…”