Table 2.

Select studies on building/home-based exposure reduction and asthma outcomes in children (2000–2017).

Reference	Population	Study design	Exposure focus	Intervention	Exposure outcome	Asthma outcome	Comments
Carter et. al.(83)	104 enrolled 6–16 y/o inner-city children with asthma (Atlanta, GA, US)	RCT Single blinded	Dust mite and cockroach allergen	Intervention 1 (n=35): allergen impermeable covers + effective roach bait, instructions to wash bedding once/wk. in hot water, and education re dust mite and cockroach cleaning measures Intervention 2 (placebo) (n=34): allergen permeable covers, instructions to wash bedding once/wk. in cold water Control 2 (n=35) Routine medical care; no home visits [85 completed study; 30/25/30] Significant allergen reduction defined as 70% decrease	No difference between intervention vs placebo in percent attaining 70% decrease in allergen reduction; cockroach allergen reduction measures ineffective	Decreased acute visits for asthma in those home visited Decreased acute visits in those allergic to dust mite who had decreased dust mite exposure	Applying allergen avoidance challenging in poor communities because of multiple sensitivities and problems applying protocols in this environment
Morgan et al. (2004) (84)	937 5–11 y/o inner-city children with asthma sensitized to ≥ 1/11 indoor allergen (7 US cities; ICAS)	RCT	Indoor allergens. ETS	Intervention (n=469): Multifaceted: 1 yr. of education + allergen impermeable covers + HEPA vacuum cleaner + bedroom HEPA air cleaner + remediation with IPM tailored to each child’s sensitization/exposure profile Control (n=468): Evaluation every 6 months	Reduction in dust mite and cockroach allergen levels	Decreased asthma symptoms during the intervention year (3.39 vs. 4.20 days) and the year after. Decreased urgent visits	Separate effects of each component of intervention unknown; No direct ETS exposure measures Cost: $1500 to $2000/child--similar to cost of mid-range ICS & albuterol for a child with moderately severe asthma
Phipatanakul et al.(2004) (85)	18 mouse infested homes of mouse sensitized inner city asthmatic children (Boston, US)	RCT	Mouse allergen	Intervention (n=12): Professionally delivered IPM Control (n=6): No IPM	Reduction (~75%) in settled dust mouse allergen levels in intervention vs. control homes	No clinical improvement in lung function or symptoms detected	Insufficient power to detect lung function or clinical response Unknown what degree of mouse allergen reduction and length of time of reduction required to improve symptoms
Krieger et al. (2005) (86)	274 4–12y/o children with asthma from low income families (Seattle-King County WA, US)	RCT	Multiple asthma “triggers”	Intervention (n=138): Multifaceted: 5–8 home visits by community health worker over 1 year including home assessment, education, support for behavior change and resources to reduce exposures Control(n=136): 1 visit, limited resources	N/A	Increased parent/caregiver actions to reduce exposures Decreased urgent visits, and increased caregiver QOL No differences in asthma symptoms between groups	Separate effects of each component of intervention unknown; Intervention not tailored to child’s sensitivities Exposures not measured Projected 4 yr. savings: $189–$721
Eggleston et al.(2005)(87)	100 6–12 y/o children with asthma from low income families (Baltimore MD, US)	RCT	PM10 & PM2.5; indoor allergens (focus on cockroach, mouse)	Intervention( n=50): Multifaceted:1 yr. of education + allergen impermeable covers + bedroom HEPA air cleaner + remediation with IPM for mice and for cockroach (if infestation signs or if child sensitized) Control (n=50): treated at end of 1-yr trial	Reductions of ~39% in PM10 & PM2.5, and ~50% in cockroach allergen	Decreased daytime asthma symptoms No differences in other asthma outcomes, including acute care and quality of life measures.	Separate effects of each component of intervention unknown; Population included some children with mild intermittent asthma symptoms and no atopy
Chew et al. (2006) (88)	3 uninhabited water-damaged homes after a major hurricane (New Orleans, LA; US)	Pre-post treatment comparison	Mold (spore counts, cultures, PCR analysis, glucan), endotoxin, and PM	Intervention: Removal of drywall, carpet, insulation, and all water-damaged furnishings	Reductions in mold and endotoxin pre-post, but high levels during clean-up	N/A	Pre- and during treatment mold and endotoxin levels were orders of magnitudes above those in homes without severe water damage Adequate respirator use recommended during clean-up
Kercsmar et al. (2006) (74)	62 2–17 y/o children with asthma in homes with mold (Cuyahoga County, IL, US)	RCT	Mold scores; allergen levels	Intervention (n=29) and Control (n=33): asthma action plan, education, individualized problem solving Intervention group only: + Household repairs and modifications	At 6-mo, but not at 12 mo., greater reduction in mold scores in intervention group compared to control	Decreased asthma symptom days and prevalence of exacerbations in intervention compared to control	Low sample size, limited power frequency of families moving complexity of applying for household repairs and working with landlords
Sever et al. (2007)(89)	60 cockroach infested homes (NC, US)	3-arm RCT	Cockroach/Bla g 1	Intervention 1 (n=20): 12-mo professional entomologist pest control Intervention 2 (n=20):12-mo contract-based services performed by pest control companies Control (n=20)	Compared to control: Intervention 1: reduction in Bla g 1(~90%) Intervention 2: No reduction	N/A	Suggest increase education of commercial pest control companies in most effective eradication methods and education of families
Pongracic et al. (2008) (90)	312 5–11 y/o inner-city children with asthma and sensitization to a rodent (subset of ICAS; 7 US cities)	RCT	Rodent allergen/Mus m 1	Intervention (N=150): ICAS (Inner-City Asthma Study) rodent module: 1 yr. of education + allergen impermeable covers + HEPA vacuum cleaner + bedroom HEPA air cleaner +filling rodent access points and setting traps throughout home Control (N=155): 97% received at least 1 other module	80% bedrooms had detectable mouse allergen. Intervention: reduction in mouse allergen (~27%) in bedroom floor but not bed Control: Increase in mouse allergen (~28%)	No primary outcome (symptom) change Decreased school absenteeism, nights of child/caretaker waking and caretaker change in plans	Did not measure rat allergen; cannot evaluate whether findings relate to change in this exposure Unknown how HEPA air purifier, which most homes received, contributed to these results
Howden-Chapman et al. (2008) (91)	409 households of 6–12 y/o children with asthma (5 New Zealand communities)	RCT	Nitrogen dioxide	Intervention (N=200): Installation of a non-polluting more effective heater (heat pump, wood pellet burner, or flued (vented) gas) before winter Control (N=209): Given replacement heater at end of 1 yr. trial	Reduction in NO2 levels in living rooms and bedrooms	No primary outcome (lung function) improvement Less health care utilization for asthma and night time awakening Fewer lower respiratory symptoms	Engagement with community coordinators Multiethnic, including Maori, who have greater burden of respiratory disease Challenges include: Complex communication Technical difficulties with Piko (for lung function measurement)
Bryant-Stephens et al. (2009)(92)	264 2–16 y/o children with asthma (Philadelphia) PA, US)	Randomized 6-mo Crossover	Dust, pests, pets, ETS	Immediate (n=144) or delayed (n=120) intervention: 6-mo (5 visit) family education+ supplies for trigger reduction (allergen impermeable covers, roach bait, mice traps, cleaning airs, storage bins, replacement for curtains/carpet) given by lay health educators	Reduction in rodents Increased use of impermeable covers (measured @ 2.5 mo. post intervention)	Decreased nighttime wheeze and cough Decreased ED and inpatient visits (1-yr, not 6-mo post intervention)	Separate effects of individual interventions unknown High drop out in the delayed intervention group The longer in the study, the better the outcome No skin testing No formal cost effectiveness analysis (cost ~$500/home)
Breysse et al. (2011) (93)	49 adults, 29 children from 31 units in a low income 3-building, 60-unit apartment complex (MN, US)	Cross-sectional health survey of pre-immediately post renovation health, followed by survey 12–18 mo. post renovation	Green specifications targeting ventilation, moisture, mold, pests, radon	Intervention: Renovation according to Enterprise Green Communities green specifications, using “healthy Housing” features. New mechanical ventilation installed(94)	Reduction in energy use (45%) Tightening of building envelope Functional exhaust fans Fresh air @ 70% of ASHRE standard Lower radon Annual average 982 indoor CO2 ppm	Immediately post renovation: Self-report of cleaner, more comfortable, safer housing Improvement in overall adult health, in non-asthma respiratory health (adults + children) and in asthma health (adults)	Potential recall bias Non-randomized, unblinded study design Non independence of health reports from residents in same apartment Potential communication problems with non-English speaking residents Potential selection bias towards healthier residents Some retrofitting required as not all renovations worked Report of health benefits appear fewer in follow up
Butz et al. (2011) (64)	126 children with asthma, residing with a smoker (Baltimore MD, US)	RCT	Indoor PM and ETS exposure	Intervention 1 (n=41):6-mo air cleaner Intervention 2 (n=41):Air cleaner + health coach Control (n=44): Delayed air cleaner	Reduction in PM levels No additional PM reduction with health coach No air nicotine or urine cotinine reduction	No change in symptom-free days	Reduction in PM in homes with smokers not sufficient to meet EPA standards for outdoor air quality Air cleaners do not reduce nicotine exposure Limitations: ventilation of household unmeasured, adherence to air cleaner not fully assessed, limited f/up time (6 mo.)
Lanphear et al.(2011) (65)	215 6–12 y/o children with asthma exposed to ≥5 cigarettes/day (Cincinnati OH, US)	RCT Double-blinded	Particle counts: >0.3μm >0.5μm	Intervention (n=110):2 active HEPA air cleaners Control (n=115): 2 inactive HEPA air cleaners	Reduction in PM >3 μm levels No air nicotine, cotinine reduction	Decreased unscheduled asthma visits No change in asthma symptoms or FENO	Baseline asthma morbidity and exposures of 2 groups not entirely comparable Efficacy of HEPA filters may vary by room size, ventilation
Mitchell et al. (2012) (95)	182 4–12 y/o children with moderate to severe asthma living in post Hurricane Katrina flooded areas (New Orleans LA, US)	Observational, pre-post intervention study	Indoor allergens, moisture and mold	Intervention: Individually tailored multi-faceted environmental intervention plus asthma counselor (timing of introduction of counselor varied)	Reduction in bedroom mold spores and in Alternaria in settled dust	Reduction (45%) in asthma symptom days Children with asthma counselor had greater symptom decrease	Separate effects of individual interventions unknown Unclear whether mold decrease occurred because of intervention
Hoppe et al. (2012) (96)	Families living in 73 flood/water damaged homes (Cedar Rapids IA, US)	Cross-sectional assessment of homes and health at two levels of remediation (in-progress (n=24) or complete (n=49))	Extensive, (e.g., Mold, bacteria, endotoxin, PM, allergens)	Intervention: Removal of drywall, carpet, insulation, and all water-damaged furnishings	Levels of mold, bacteria, endotoxin, PM, glucan higher in homes with remediation in progress compared with homes with remediation complete	Compared to before the flood, residents of in-progress homes reported more allergies All residents reported more and wheeze and meds for breathing problems	Cross-sectional Stage of in-progress clean up variable Many in-progress families not moved back full time Potential participation bias
Turyk et al. (2013) (97)	218 <18 y/o children with asthma from 138 families (Chicago IL, US)	Observational, pre-post intervention study		Intervention: Asthma management education, plus individually tailored low-cost asthma home trigger remediation (e.g., allergen impermeable covers, home walkthrough covering reduction in asthma triggers, provision of environmental remediation tools), and referrals to social or medical agencies when appropriate	Reduction in many environmental triggers	Lack of improvement in asthma controller use and other asthma management activities Decreased asthma symptoms, urgent care and ED visits, hospitalization, missed school days, missed work days for caretakers	Separate effects of individual interventions unknown Mobility high, unclear how that influenced intervention or outcome Lack of data on allergen sensitization or lung function
Breysse et al. (2014)(98)	102 low income households in rental properties with 1 or more children with not well-controlled asthma(King Country WA, US)	Observational, pre-post intervention study with historical comparison group		Intervention (n=34): Weatherization plus community health worker(CHW) education Historical comparison group (n=68): CHW education without weatherization	Reduction in evidence of water damage greater with intervention group, but No consistent evidence for greater improvement in intervention vs. comparison group in other environmental exposures	Increased asthma control Increased caregiver quality-of-life	Separate effects of weatherization and CHW not demonstrated Small study size IPM not used
Colton et al. (2014) (99)	31 low income households in rental housing	Observational comparison of exposures and health in green vs conventional housing, including in those who move between housing types.		Intervention (n=18): Move from conventional to new buildings designed to green standards. Smoke-free policies and IPM practices employed. Control 1(n=6): Move from conventional to conventional housing Control 2(n=7): Live in conventional housing [61 visits including pre and post for 24 who moved]	Green vs conventional housing: Lower PM2.5, NO2, and nicotine Fewer reports of mold, pests, inadequate ventilation, and stuffiness	Fewer sick building syndrome symptoms	Suggested benefits of move to green housing need further assessment Number of controls limit pre-post analysis
Colton et al. (2015)(80)	235 households in 3 Boston public housing 188 residents (80%) with 2 visits	Observational comparison of conditions and health in green vs conventional housing. Visits included home inspection and questionnaire.		Visits to Green Units (n = 201) and conventional Public Housing Units (n = 222)	Fewer reports and observations of mold, pests, inadequate ventilation, and secondhand smoke in green compared to conventional housing.	Fewer asthma symptoms, hospital visits, school absences for children in green compared to conventional public housing.	Suggested benefits of move to green housing Effects observed only for children with asthma; effects on adults not certain.
DiMango et al. (2016)(100)	110 adults and 137 children with asthma sensitized and exposed to at least 1 indoor allergen	RCT	Key allergens in vacuumed settled dust (cat, dog, dust mite, cockroach and mouse)	Following optimization of asthma treatment and control, randomization to: Intervention (n=125): Multifaceted: 40-wk education + allergen impermeable covers + HEPA vacuum cleaner + bedroom HEPA air cleaner Control (n=122): education not related to allergen avoidance	Intervention: reduction in all allergens (cat, dog, dust mite allergens; cockroach, mouse). Control: reduction in dust mite and mouse allergen (bedroom) and cockroach allergen (kitchen).	Improvement in asthma control in both arms with no difference between groups.	Lack of difference between intervention and control groups in achieved allergen reduction may explain lack of effect of active intervention on asthma outcomes Intervention did not include intensive targeted IPM; post hoc analyses suggested improvement when mouse allergen was reduced Not powered to assess effects in adults v children
Matsui et al (2017)(101)	350 children and adolescents with asthma sensitized and exposed to mouse allergen (Baltimore MD; Boston MA, US)	RCT	Mouse allergen	IPM+Education Group (n=181): application of rodenticide, sealing holes that could serve as entry points for mice, trap placement, targeted cleaning, allergen-proof mattress/pillow encasements, portable air purifiers. If infestation persisted or recurred, additional treatments were delivered. Education (n=180): Written material and demonstration of the materials needed to set traps and seal holes.	No difference in mouse allergen levels between groups. ~70% reduction in mouse allergen in both groups.	No difference in asthma symptoms or other asthma outcomes between groups. Across both groups, reduction in mouse allergen was associated with improvements in asthma symptoms, rescue medication use, acute visits, and mouse-specific IgE.	Large reduction in mouse allergen observed in education group was unexpected. Results suggest education alone may be effective in some populations, but study did not include control group that received no education about pest management. Majority of children’s homes continued to have mouse allergen levels above levels previously associated with asthma morbidity.
Rabito et al (2017)(102)	102 5–7 y/o children with moderate to severe asthma in cockroach-infested homes(New Orleans, LA; US)	RCT	Cockroach allergen	Intervention (n=53): 12-mo with trapping & bait placement at baseline, 1, 3, 6, 9, and 12 mo in areas with evidence of cockroach. Control (n=49): 12-mo with trapping but no bait placement at baseline, 1, 3, 6, 9, and 12 mo after baseline.	Fewer cockroaches in intervention homes.	Fewer asthma symptoms and unscheduled health care utilization. Fewer with FEV1<80% predicted.	Suggested benefits of single intervention with strategic insecticidal bait placement. Limited by sample size and lack of blinded treatment and blinded assessment personnel.
Murray et al (2017)(103)	286 3–17 y/o mite-sensitized children with emergency hospital attendance for asthma exacerbation (North-West England)	RCT [Age group (3–10 y; 11–17 y) stratified]	Dust mite allergen	Intervention (n=146): 12-mo with mite-impermeable bed encasings. Control (n=138): 12-mo with no encasings.	Lower dust mite (Der p 1) levels.	Fewer hospital visits with an exacerbation. No difference in risk of prednisolone use for exacerbation.	Suggested benefit of single intervention with mite-impermeable bed encasings. Limited in that all data on exacerbations and oral corticosteroids reported by parents/carers. No measured adherence to meds or asthma trigger data.

RCT=Randomized controlled trial; ETS=environmental tobacco smoke; IPM=integrated pest management; PM=particulate mass; ICS=inhaled corticosteroids; QOL=quality of life; ICAS=Inner City Asthma Study. References (2000–2016) selected by Workshop participants as representative and illustrative of asthma management intervention studies in children.