The 2002 Los Angeles County Health Survey
(LACHS) was commissioned by the Los Angeles County
Department of Health Services and conducted by Field
Research Corporation between October 2002 and March
2003. The 2002 survey was supported by grants from
First 5 LA, the California Department of Health Services
through grants to Family Health, Tobacco Control and
Prevention, and Alcohol and Drug Programs, and from the
Public Health Response and Bioterrorism Preparedness
federal grant.
The 2002 LACHS study expanded upon two previous
LACHS studies conducted for the county in 1997 and
1999. 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: 8,167 adults age 18 years or older,
living in Los Angeles County, were interviewed for the
Adult survey. A sample of 5,995 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 and
Vietnamese.
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 57% 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%.