2005 Los Angeles County Health Survey Background Summary & Methodology
The 2005 Los Angeles County Health Survey (LACHS) was
commissioned by the Los Angeles County Department of
Health Services and conducted by Field Research
Corporation between January 2005 and June 2005. The 2005
survey was supported by grants from First 5 LA, the
California Department of Health Services through grants
to Family Health, Tobacco Control and Prevention,
Alcohol and Drug Program, Office of AIDS Programs, and from
the Public Health Response and Bioterrorism Preparedness
federal grant.
The 2005 LACHS study expanded upon three previous LACHS
studies conducted for the county in 1997, 1999, and
2002. Each LACHS is structured to include both the
Adult and Child survey components. The overall
objectives of each survey is to update key health status
indicators, health-related behaviors, health insurance
coverage and access to health care among adults and
children living in Los Angeles County (across the
county's 26 health districts and 8 service planning
areas). The study also supports the examination of the
health behaviors and characteristics of the county's
major racial and ethnic groups as well as those
households whose incomes place them below the federal
poverty level. The goal is to provide health planners,
policymakers, community leaders and the public itself
with information about the health and health care needs
of Los Angeles residents.
Sample Size:
8648 adults age 18 years or older, living in Los Angeles County, were interviewed for the Adult survey. A sample of 6032 interviews was completed among parents/caregivers of children age 17 years or less for the Child Survey. Respondents were randomly selected per household by telephone using an unrestricted random digit dial sampling methodology inclusive of all eligible telephone households in Los Angeles County.Languages:
Interviews were conducted in English, Spanish, Chinese (Mandarin and Cantonese), Korean, Vietnamese and Armenian.Weighting:
To generalize the survey data to the overall County population, it was necessary to develop appropriate weights. These weights adjusted for differences in the probability of selection of respondents in each survey population attributable to the sampling design, and for differential contact and response rates among sub-populations during the survey process.Cooperation Rate:
The cooperation rate for the Adult portion of the survey was 49% and the cooperation rate for the Child survey was 78%.Estimating Sampling Error:
In any survey that includes sampling, some degree of error ("sampling error") is introduced by chance alone, even when the sample is chosen randomly. In the present survey, if 50% of the overall sample of adults answered "yes" to a specific question, the sampling error would be plus or minus 1.2 percentage points at the 95% confidence level. This means that if all adults in the population were asked the above question, there is a 95% chance the result would be between 48.8% and 51.2%.Topics of 2005 Health Survey