Table 2.

Asthma intervenion trials.

Study	Intervention type	Description of intervention	Home environmental effects	Health effects
Brunekreef et al. 2002	Mechanical	Mite-impermeable bedding covers	Lower house dust mite count	No important clinical benefits in children < 2 years of age
Halken 2004	Mechanical	Mite-impermeable bedding covers	Lower house dust mite count	Reduced need for inhaled steroids in asthmatic children
Popplewell et al. 2000	Mechanical	HEPA and standard vacuum cleaners	Reduced house dust mite, cat and dog allergens with HEPA	Improved peak respiratory flow rate, bronchodilator usage
Warner et al. 2002	Mechanical	HEPA vacuum cleaners and whole-house mechanical ventilation system	Reduced dampness and house dust mite count	Improved histamine levels with whole-house ventilation; no significant added benefit from HEPA
van der Heide 1999	Mechanical	Bedroom and living room air cleaners	Reduced airborne cat and dog allergen	Improved peak expiratory flow rate; reduced airway hyper responsiveness
Somerville et al. 2000	Mechanical	Central heating systems	Reduced dampness; improved energy efficiency	Improved asthma outcome measures; fewer sick school days
Wakefield et al. 2002	Education	Parents refraining from smoking in the home	No significant difference in parental behavior	No significant improvement in children’s health
McIntosh et al. 1994	Education	Parents refraining from smoking in the home	No significant difference in parental behavior	No significant improvement in children’s health
Fitzpatrick et al. 1992	Education	Asthma camp for asthmatic children and their parents	Improved use of medication and breathing exercises	Reduced school absences, emergency department visits, and hospitalizations
Krieger et al. 2005	Combination	Community health workers deployed to Seattle, WA, homes: high-intensity, low-intensity interventions	Reduction in numerous home allergens	Reduced children’s asthma symptom days and use of urgent health services
NCICAS  Kattan et al. 2005  Morgan et al. 2004  Sullivan et al. 2002	Combination	Seven cities: comprehensive home environmental interventions and education targeted to children’s allergies	Reduction in numerous home allergens	Reduction in asthma symptom days in children, use of albuterol inhalers, and unscheduled clinic visits
Carter et al. 2001 Hayden et al. 1997	Combination	Interventions in homes of hospitalized asthmatic children with home visits: active, placebo, and control	Reduction in house dust mite	Reduced children’s acute asthma hospital visits; no difference in active vs. placebo groups