2002 Los Angeles County Health Survey Background Summary & Methodology

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%.

Topics of 2002 Health Survey

Main Page of LA County Health Survey