Krieger 2005.
| Methods |
Study design: randomized controlled trial Sampling frame: Households with a child age 4 to 12 with diagnosed persistent asthma who spent at least 50% of nights there, with income below 200% of 1996 poverty threshold or child enrolled in Medicaid, English‐, Spanish‐, or Vietnamese‐speaking caregiver, in King County Sampling method: participants recruited from community and public health clinics, local hospitals and emergency departments, and referrals from community residents and agencies Collection method: in‐home interview |
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| Participants |
Communities: King County, Washington Country: USA Ages included in assessment: 4 to 12 years Reasons provided for selection of intervention community: coalition established to serve a specific racially and ethnically diverse urban community of concentrated disadvantage Intervention community (population size): King County, WA (not stated) |
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| Interventions |
Name of intervention: Seattle‐King County Healthy Homes Project Theory: Social Cognitive Theory and Transtheoretical Stages of Change Model Aim: to assess the effectiveness of a community health worker intervention focused on reducing exposure to indoor asthma triggers Description of costs and resources: Estimated marginal cost of high‐intensity intervention relative to low‐intensity intervention was $124,000. Hoover provided vacuums at cost, Group Health Co‐operative donated free enrollment in tobacco cessation program, and the local hazardous waste management program donated green cleaning kits and pails Components of the intervention: “high‐intensity intervention”: A community health worker conducted an initial home environmental assessment, provided individualized action plans, and made additional visits over a 12‐month period to provide education, support, materials such as low‐emission vacuums and bedding encasements), assistance with roach and rodent eradication, and advocacy for improved housing conditions. “Low‐intensity intervention”: received the initial assessment, home action plan, limited education, and bedding encasements. Start date: 1999 |
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| Outcomes | Outcomes and measures: 1. Days with asthma symptoms/2 weeks (reported by caregiver) 2. Urgent health services use for asthma/2 months (reported by caregiver) | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Method of randomization not stated |
| Allocation concealment (selection bias) | Unclear risk | Method of allocation concealment not specified |
| Baseline outcome measurement similar | Low risk | Baseline outcome measurements similar between 2 groups |
| Baseline characteristics similar | Unclear risk | Baseline characteristics similar on most factors, except high‐intensity intervention group tended to have more severe asthma than low‐intensity group |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Study group was revealed to some interviewers at exit interview |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | 12% lost to follow‐up, proportion lost similar between 2 groups, and study authors state that completers were similar at baseline across intervention groups. Primary analysis included only study completers; intention‐to‐treat analysis presented in text for only 1 of 2 main outcomes |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Participants and personnel not blinded |
| Protection against contamination | Unclear risk | None reported, unclear whether study participants from the same county would have interaction with one another |
| Selective reporting (reporting bias) | Low risk | Main study outcomes reported |