Nurse case management and housing interventions reduce allergen exposures: the Milwaukee randomized controlled trial

Abstract

Objective: We examined the impact of a combination of home environmental interventions and nurse case management services on total settled dust loadings and on allergen concentrations in the homes of asthmatic children. METHODS Using a randomized longitudinal controlled trial study design, we randomly assigned homes of asthmatic children in Milwaukee to either a control (n = 64) or an intervention (n = 57) group. Control group homes received a visual assessment, education, bed/pillow dust mite encasings, and treatment of lead-based paint hazards. The intervention group received these same services plus nurse case management that included tailored, individual asthma action plans, provision of minor home repairs, home cleaning using special vacuuming and wet washing, and integrated pest management. Dust vacuum samples were collected from measured surface areas of floors in the TV room, kitchen, and child's bedroom at baseline and at three-, six-, and 12-month follow-up visits. Dust loading (mass per surface area) is a means of measuring total dust and the total amount of allergen present.

Results: For the intervention group, geometric mean dust loadings declined significantly from baseline (39 milligrams per square foot [mg/ft2]) to postintervention (11 mg/ft2) (p < 0.001). Baseline dust loading, treatment group, visit, and season were significant predictors of follow-up dust loadings. Mean post-intervention dust loadings were 72% higher in the control group. The total amount of allergen in settled house dust declined significantly following the intervention because total dust loading declined; the concentration of allergens in settled dust did not change significantly.

Conclusion: The combination of nurse case management and home environmental interventions promotes collaboration between health and housing professionals and is effective in reducing exposures to allergens in settled dust.

Figure 1

Sieved dust loading (mg/ft²): actual at baseline and model predicted at follow-up, with the average seasonal effect, from a randomized controlled study of nurse case management and housing intervention effects on allergen exposures among asthmatic children in Milwaukee, 2003–2005

Figure 2

Percent of bla g 1 (cockroach allergen) concentrations greater than the limit of detection by visit and study group (all rooms and surface types combined): results from a randomized controlled study of nurse case management and housing intervention effects on allergen exposures among asthmatic children in Milwaukee, 2003–2005

Figure 3

Percent of bla g 2 (cockroach allergen) concentrations greater than the limit of detection by visit and study group (all rooms and surface types combined): results from a randomized controlled study of nurse case management and housing intervention effects on allergen exposures among asthmatic children in Milwaukee, 2003–2005

Figure 4

Percent of der f 1 (dust mite allergen) concentrations greater than the limit of detection by visit and study group (all rooms and surface types combined): results from a randomized controlled study of nurse case management and housing intervention effects on allergen exposures among asthmatic children in Milwaukee, 2003–2005

Figure 5

Percent of mus m 1 (mouse allergen) concentrations greater than the limit of detection by visit and study group (all rooms and surface types combined): results from a randomized controlled study of nurse case management and housing intervention effects on allergen exposures among asthmatic children in Milwaukee, 2003–2005