Community Health Survey: Methodology
The Community Health Survey (CHS) has been conducted annually by the New York City Department of Health and Mental Hygiene since 2002. Data collected from the CHS are used to better understand the health and risk behaviors of New Yorkers and to track key indicators over time. For more information on the CHS, visit:
The target population of the CHS includes non-institutionalized adults aged 18 and older who live in a household with a landline telephone in New York City (the five borough area). Starting in 2009, adults living in households with only cell phones have also been included in the survey.
Most years the CHS includes approximately 125 questions, covering the following health topics: general health status and mental health, health care access, cardiovascular health, diabetes, asthma, immunizations, nutrition and physical activity, smoking, HIV, sexual behavior, alcohol consumption, cancer screening and other health topics. A core group of demographics variables are included every year to facilitate weighting and comparisons among different groups of New Yorkers.
The CHS uses a stratified random sample to produce neighborhood and citywide estimates. Strata are defined using the United Hospital Fund's (UHF) neighborhood designation, modified slightly for the addition of new zip codes since UHF's initial definitions. There are 42 UHF neighborhoods in NYC, each defined by several adjoining zip codes.
Starting in 2009, a second sample consisting of cell-only households with New York City exchanges was added. This design is non-overlapping because in the cell-only sample, adults living in households with landline telephones were screened out.
A computer-assisted telephone interviewing (CATI) system is used to collect the survey data. The CHS sampling frame was constructed with a list of telephone numbers provided by a commercial vendor. Upon agreement to participate in the survey, one adult is randomly selected from the household to complete the interview.
Interviewing is conducted in a variety of languages. Every year, the questionnaire is translated from English into Spanish, Russian, and Chinese. Some years, live translation services are provided by Language Line (including Hindi, Arabic, Farsi, and Haitian Creole). From 2002 to 2007 data were collected by CUNY Baruch College Survey Research Unit. Since 2008, Abt-SRBI, a survey research company based in New York City, has been collecting data for the CHS. Typically, data collection begins in March of the study year and ends in November. The average length of the survey is 25 minutes.
The survey sampling methodology does not capture the following groups: households without any telephone service and (prior to 2009) households that only have a cell phone. The CHS also excludes adults living in institutional group housing, such as college dormitories.
SAMPLE SIZE, RESPONSE AND COOPERATION RATES
The sample size (completed interviews), the response rate and the cooperation rate are provided for each year of the survey in the table below.
Response and cooperation rates are measurements of overall survey participation among those sampled. More specifically, the Cooperation Rate is defined as the number of those who participated in the survey, divided by the number of individuals in the sample who were contacted and identified as eligible. The Response Rate is a more conservative measure and is defined as the number of individuals who participated in the survey, divided by the number of individuals in the sample who were contacted and identified as eligible, as well as those never contacted and those with unknown elgibility.
While there are multiple ways to calculate both these rates, the Health Department uses AAPOR's third definition (1) for the CHS, as provided in the table.
*RR and CR rates for 2009 - 2011 are combined landline and cell rates. Complete telephone disposition reports are available for both the landline and cell-phone samples.
In order to appropriately analyze CHS data, a weight is applied to each record. The weight consists of an adjustment for the probability of selection (number of adults in each household / number of residential telephone lines), as well as a post-stratification weight. The post-stratification weights are created by weighting each record up to the population of the UHF neighborhood, while taking into account the respondent's age, gender and race. Starting in 2009, responses were also weighted to account for the distribution of the adult population comprising three telephone usage categories (landline only, landline and cell, cell only) using data from the 2008 New York City Housing and Vacancy Survey.
If you need assistance with the data, wish to suggest additional variables to be added, or have additional questions about the survey's methodology, please send an email to firstname.lastname@example.org.
(1) The American Association for Public Opinion Research. 2009. Standard definitions: Final Dispositions of Case Codes and Outcome Rates for Surveys. 6th edition. Lenexa, Kansas: AAPOR.
Last updated: June 2013.