Routine surveys are particularly valuable surveillance tools for chronic diseases and health-related behaviors. In general, surveys are most useful for disease surveillance when they ask people about information for which they may be the most valid and reliable source (e.g., their own private behaviors, attitudes, or mental health status), or for which they can report with reasonable reliability, even if they are not the only or most valid source of information (e.g., whether he or she went to the doctor in the past month). In some cases, surveys link such self-reported data to data collected from other sources. The following sections of this chapter discuss major surveys at the national level as well as examples of state and local surveys. The discussion includes a description of the purpose of the survey, its methods, the extent to which data are collected on topics relevant to cardiovascular and chronic pulmonary diseases, and how data are disseminated. Each description includes a brief discussion of strengths and limitations.
The Behavioral Risk Factors Surveillance System (BRFSS) The BRFSS, nationally coordinated by the CDC and conducted by state health departments in all 50 states and the District of Columbia, is a state-based system of cross-sectional health surveys of adults. It collects information on health risk behaviors, preventive health practices, and healthcare access, primarily related to the areas of chronic disease and injuries. The BRFSS has been the primary source of state-level population health estimates from surveys and has been available in all states since 1984. States may request information from the CDC; the information includes samples of telephone numbers with substate or local strata, an option taken by 41 states. The core questionnaire is required of all states. Data collection is funded by several sources, including state and federal agencies and private organizations. The CDC supports a portion of the data collection efforts, and the states provide their own funding for optional modules and state-added questions. Private partners also support collection of data in the different states. BRFSS data are widely used for policy development and advocacy at both the national and state levels.
The BRFSS questionnaire is administered on a continuous basis by telephone using random-digit dial sampling methods. The design consists of a probability sample of all households with telephones in the state. Survey respondents are between the ages of 18 and 99, and only one adult per household is interviewed. As part of the core survey questionnaire developed by the CDC, self-reported information is routinely collected on diagnosed health conditions, including stroke, congestive heart failure (CHF), coronary heart disease (CHD), diabetes, and asthma, but not chronic obstructive pulmonary disease (COPD). The CDC provides an optional module on COPD that states may include at their discretion (and expense). The core questionnaire also collects information on diagnosis of cardiovascular risk factors, including hypertension, diabetes, and high cholesterol. Questions on tobacco use, alcohol consumption, physical activity, nutrition, and weight status, including consumption of fruits and vegetables, are also asked. Limited data are also collected on access to, and use of, healthcare services, including preventive services.
Sociodemographic data collected include age, sex, race/ethnicity, marital status, education, employment, and household income. Most states and localities with BRFSS surveys have the ability to examine prevalence of health conditions and risk factors by major race/ethnic and income groups. Race/ethnicity is collected as Hispanic, white, black or African American, Asian, Native Hawaiian or Other Pacific Islander, and American Indian or Alaskan Native. Only some states collect explicit data on nativity. Geographically, in addition to state-level estimates, the CDC currently aggregates BRFSS data to produce a limited set of annual estimates for 177 metropolitan and micropolitan statistical areas and 166 counties (which vary from year to year due to sampling variations).
The BRFSS provides annual findings and data files via the website //www.cdc.gov/brfss/ and on CD-ROM, with additional information on survey instruments, other documentation materials, sets of trend analysis tables for the states and the nation, and sets of demographic-specific tables for estimates of risks and conditions, including bar charts for comparison of areas or survey years. Results are also easily accessible via interactive tools, although the “Web Enabled Analysis Tool” is available for limited survey years. At the time this report was in press, data were available from 1984 through 2009. More than 1,500 peer-reviewed journal articles have been published using BRFSS data.
Strengths and limitations The BRFSS has numerous strengths for use in surveillance. The CDC’s strong control over survey questions to be used ensures that data collected by each state’s BRFSS are reasonably comparable to data collected by other states. As an ongoing survey, it enables tracking of trends. The BRFSS collects information on prevalence of self-reported asthma/adult asthma history, cardiovascular disease (heart attack/stroke), diabetes, and health risk factors that include cholesterol and hypertension awareness (CDC, 2009b). It is adaptable for local use at the expense of each jurisdiction that wishes to use it.
The prevention of CVD and chronic lung disease is a long-term effort that must address risk factors throughout the life course, and the absence of significant information collected about children and adolescents means that the BRFSS does not provide local surveillance of obesity, diet, and physical activity in these age groups. Although other surveys do collect such information on children and adolescents, not being able to link that information to parents’ information is a handicap for prevention efforts. In addition, the BRFSS’s thin measurement of health insurance coverage and access to care limits its value for assessing factors that affect the receipt of clinical preventive and disease monitoring services.
Because it typically does not collect locally representative survey samples, the BRFSS has limited use for local-level analyses and research. Such research is necessary to support efforts to address geographic and social disparities. The CDC recognized the need for local data and used aggregated BRFSS data to produce a limited set of annual estimates for local geographic areas, but these vary from year to year due to sampling variations. It is doubtful that these can meet needs for in-depth data for research and analysis of local variations in chronic diseases and their risk factors. Nearly a third of states have expanded state BRFSS samples at their own expense to generate representative data sets for local substate strata. Such efforts are described in the section below on state surveys.
The BRFSS also relies on self-reported information. It does not collect blood specimens or contain information on incidence of disease and health outcomes or data on chronic bronchitis or emphysema (IOM, 2009). The required core and optional module BRFSS questionnaires of the survey examine disease history and signs and symptoms of disease (e.g., shortness of breath), but the BRFSS core does not collect national data about chronic lung disease, with the exception of asthma. Furthermore, response rates to the BRFSS are lower than ideal and declining, a limitation that it shares with all telephone surveys, and as a telephone survey, it does not include people without telephones.
Youth Risk Behavior Surveillance System (YRBSS) The YRBSS is focused on monitoring priority health risk behavior, including physical inactivity, dietary behaviors, the prevalence of obesity, and asthma among students in grades 9–12 (CDC: //www.cdc.gov/HealthyYouth/yrbs/index.htm). The survey is conducted by the CDC and by state, territorial, and local education and health agencies and tribal governments. The purpose of this survey is to provide critical behavioral information on adolescents nationwide. At the state level, information is used for school- and community-based program evaluation and policy development as well as for national research and surveillance of health behavior and health risk disparities.
Data are collected every other year, usually during the spring semester. Information is collected from a nationally representative sample of public and private high school students (grades 9–12) in each participating jurisdiction as well as a representative sample of students enrolled in middle schools and alternative schools. The survey is administered in 10 to 15 sites per cycle. A class is randomly selected to participate, and all students in that class are asked to take part in the survey. The survey is a self-administered written questionnaire conducted in school classrooms.
The YRBSS monitors six categories of priority health risk behaviors among youth and young adults, three of which pertain to CVD risk factors. These include behaviors that contribute to unintentional injuries and violence; sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases, including HIV infection; tobacco use; alcohol and other drug use; unhealthy dietary behaviors; and physical inactivity. In addition, the YRBSS monitors the prevalence of obesity, diagnosed asthma, and prevalence of asthma attacks.
Black and Hispanic students are oversampled in the YRBSS to examine race- and ethnic-specific estimates, but the 2009 sample size from other racial and ethnic groups is “too small to permit meaningful analysis” at the national level (//www.cdc.gov/HealthyYouth/yrbs/pdf/press_release_yrbs.pdf). However, some states and localities have sufficiently diverse samples to examine other race and ethnic subgroups. No information is collected regarding household or neighborhood income or nativity.
Similar to the BRFSS, the CDC provides annual findings and data files via the website www.cdc.gov/yrbs,2 with additional information on survey instruments and other documentation materials. Results are also easily accessible to non-researchers via interactive tools and summary tables that can be queried.
Strengths and limitations The YRBSS shares many of the same strengths as the BRFSS for surveillance, despite the different methodologic design. Like the BRFSS, the CDC’s control over core survey questions to be used in the YRBSS ensures that data collected by each state are comparable to data collected by other states, and results are summarized in an annual Morbidity and Mortality Weekly Report (MMWR). As an ongoing cross-sectional survey, it enables tracking of trends in prevalence. Unlike the BRFSS, the reported response rate of YRBSS surveys is typically 70 percent or greater. Finally, the CDC allows states and localities to add a small subset of questions of local import, thus making it somewhat flexible for local adaptation. The information collected enables surveillance of the prevalence of self-reported asthma and health risk factors (CDC, 2010).
Although the YRBSS has several strengths, its main shortcomings include its limited representativeness and lack of detailed questions on risk factors for CVD and other chronic diseases. In most states and localities, the YRBSS is conducted using sampling frames of public high schools only, and thus it is not generalizable to private, parochial, or some vocational high school students, nor does it include adolescents who have dropped out of high school. In terms of risk factors, the survey does not collect detailed information on factors such as family medical history, food consumption or physical activity patterns, or access to clinical and preventive services. In addition, the lack of information on household or neighborhood socioeconomic status, nativity, or ancestry limits the ability to examine disparities in risk factors. The YRBSS does not collect information that could link adolescents’ responses to information on adults, precluding analyses of risk factors within families and households. Because it does not collect locally representative survey samples, the YRBSS has limited use for local-level analyses and research. Finally, like the BRFSS, the YRBSS relies on self-reported information and does not collect blood specimens nor does it contain information on incidence of disease and health outcomes, chronic bronchitis, or emphysema (IOM, 2009).
National Health Interview Survey (NHIS) The NHIS has monitored the health of the nation since 1957. It is a federally funded survey conducted by the National Center for Health Statistics, which provides data that are used widely to monitor trends in illness and disability, to progress toward achieving national health objectives, for determining barriers to accessing and using appropriate health care, and for evaluating federal health programs. The data also are used for public health research and policy development nationwide and regionally.
The NHIS is a cross-sectional household interview survey of men and women between the ages of 1 and 99. It is conducted in English and Spanish by interviewers employed and trained by the U.S. Census Bureau. The sampling plan follows a multistage area probability design that permits the representative sampling of households and non-institutional group quarters (e.g., college dormitories), and the plan is redesigned after every decennial census. All states and the District of Columbia are included in the sample. Sampling takes into account multiple geographic levels (e.g., local, state, national), but the sampling design is primarily aimed at making national and regional estimates.
For the Family Core component, all adult members of the household aged 17 and older who are at home at the time of the interview are invited to participate and to respond for themselves. Information about children and adults not at home during the interview can be provided by a responsible adult family member who is 18 or older and who resides in the household. For the Sample Adult questionnaire, one civilian adult per family is randomly selected and responds for her- or himself. Data are collected annually and continuously, with a different, large cross-sectional sample of approximately 35,000 households each year, with a response rate of nearly 90 percent of eligible households (//www.cdc.gov/nchs/nhis/about_nhis.htm).
The NHIS questionnaire uses a computer-assisted personal interviewing (CAPI) model. The revised NHIS questionnaire, implemented since 1997, has core questions and supplements. The core contains four major components: Household, Family, Sample Adult, and Sample Child. The household component collects limited demographic information on all of the individuals living in a particular house. The family component verifies and collects additional demographic information on each member from each family in the house and collects data on topics such as health status and limitations, injuries, healthcare access and use, health insurance, and income and assets. The supplements are used to respond to new public health data needs as they arise, particularly those for which other federal agencies provide funding. The most recently published NHIS core questionnaire includes 5 questions on diabetes, 13 questions about CHD and stroke, 5 on asthma, 1 on emphysema, and 1 on bronchitis.
The current NHIS sample design oversamples blacks, Hispanics, and Asians and persons over age 65. National and regional prevalence estimates on conditions in these race/ethnicity and age groups, as well as by household income group and nativity, are robust.
Data files are released to the public through the NHIS website. The results of different studies using NHIS data are published in several types of reports released through the Internet or in journal articles. Information is also available at //www.cdc.gov/nchs/nhis.htm.
Strengths and limitations The NHIS serves as the nation’s benchmark health survey. The main strengths of the NHIS are its representativeness, large sample size, adequate sampling of minorities, good response rates, and data on CVD and chronic lung conditions and risk factors. Incidence of self-reported diabetes and CVD can also be roughly estimated, and it is possible to link the survey to national mortality statistics.
The major limitations of NHIS are the lack of physical examinations or directly measured risk factors and disease, and the inability to generate local estimates. Larger states (now approximately 20) have sufficient sample sizes so that reliable state estimates can be made, although that is not the case for the remaining states.
National Health and Nutrition Examination Survey (NHANES) A federally funded survey, also conducted since the early 1960s3 by the National Center for Health Statistics, NHANES is the largest and longest running national source of objectively measured health and nutrition data. Data are collected on a broad range of health topics through personal household interviews, physical examinations, and laboratory testing. NHANES data provide objective assessments of prevalence of major chronic and infectious diseases nationally, and they generate key indicators of disease management for benchmarking purposes. They are used for surveillance and policy development by a range of federal agencies, and in etiologic research by a wide range of government, academic, and other institutions. Historically, NHANES was conducted periodically, but starting in 1999, NHANES has been in the field continuously. NHANES is designed to assess the health and nutritional status of a statistically representative sample of the civilian, noninstitutionalized population of the continental United States. NHANES conducts a cross-sectional, household-based survey of nearly 10,000 adults and children aged 2 months and older. The sampling plan follows a multistage area probability design that permits the representative sampling of households. Health measurements are performed in specially designed and equipped mobile centers, which travel to locations nationwide. The study team consists of a physician, medical and health technicians, and dietary and health interviewers. Many of the study staff are bilingual in English and Spanish. A series of computer-assisted questionnaires are administered in both the home and in a mobile examination center, followed by a physical examination, and finally, biological specimens are collected as part of a laboratory component.
Detailed information on chronic conditions—including cardiovascular disease, diabetes, and respiratory health and disease—are collected by questionnaire, and participants undergo comprehensive dietary interviews and body measurements. The physical examination includes several measures relevant to CVD and respiratory diseases, including blood pressure and spirometry, as well as cardiovascular fitness, body mass index, and body composition. Relevant biomarkers include cholesterol and triglyceride measures, C-reactive protein, and fasting plasma glucose. NHANES uses collected data to produce estimates of medically defined prevalence of CVD and its clinical risk factors, diabetes, and lung diseases (asthma, chronic bronchitis, emphysema) in the United States.
The current NHANES sample design oversamples blacks and Hispanics, and a new feature of the current sample design is that Asian persons are also oversampled. Detailed information is also collected on household income, nativity, education, and occupation, allowing for fairly sophisticated analysis of health disparities.
The continuous NHANES survey data are released on public-use data files in 2-year increments. Information about NHANES, downloadable public-use data sets, and published reports are made available through the Internet (//www.cdc.gov/nchs/nhanes.htm) and on easy-to-use CD-ROMs. More than 10,000 peer-reviewed journal articles have been published using NHANES data; a bibliography is available on the survey homepage.
Strengths and limitations NHANES is also a benchmark national health survey. It is one of the few population-based surveys that include validated examination measures, biological specimen collection, and limited measures of health status. Rigorous training in recruitment and data collection ensures high response rates, national representativeness, and high-quality data collection. The sample size is large enough for fairly precise prevalence measures at the national level. The national serologic repository allows for trend estimation of newly emerging biomarkers, such as C-reactive protein.
Since the inception of the continuous NHANES, any 2-year analysis may be limited in sample size, and statistical power consideration should be used to determine if sample size is sufficient for a particular analysis or if additional years of the survey need to be combined to produce statistically reliable analysis. Interview (questionnaire) data are based on self-reports and are therefore subject to recall problems, misunderstanding of the question, and a variety of other factors. Despite high standards for data collection, examination data and laboratory data are also subject to measurement variation and possible examiner effects. The survey does not collect data on incidence of acute CVD events or exacerbations of chronic lung disease. Finally, the cohort is not large enough to generate state or local prevalence estimates.
Nearly a dozen states have established separate surveys to meet their needs for local and state population health data. The growth of state and local health surveys is a positive development, demonstrating that policy makers at those levels recognize and are responding to the need for population health data. Although these surveys differ in the topics covered, measures used, and sample designs, many adopt designs and questions from the national surveys described above, and they have considerable use for tracking change and disparities in CVD and chronic lung disease within their target geographic areas. Their value for a national surveillance system is limited in measuring differences across geographic domains for which consistency of measurement is critical (Gold et al., 2008). A small number of states are experimenting with health examination surveys modeled after NHANES, including the Survey of the Health of Wisconsin (SHOW) (//www.show.wisc.edu/) and the Arkansas Cardiovascular Health Survey (//www.healthy.arkansas.gov/programsServices/chronicDisease/Initiatives/Documents/ARCHES/ARCHESQuestionnaire.pdf). The committee selected three examples of ongoing state telephone surveys to illustrate these developments.
California Health Interview Survey (CHIS) One of the nation’s largest ongoing health surveys, the CHIS is the state’s primary source of data for public health surveillance and tracking of changes in health insurance coverage as well as eligibility for public healthcare coverage programs. The CHIS covers a broad range of health issues, including health conditions and behaviors, mental health, health insurance, healthcare use and access, and special modules on the health of women, children, and persons over age 65. CHIS data are used for policy development and advocacy within California at both the state and county levels. They are also used for national research and surveillance of racial, ethnic, and other social disparities in health and health care. The CHIS is funded by multiple public agencies and private organizations at the federal, state, and local levels.
Over any 2-year period, the CHIS conducts telephone interviews with about 50,000 households, selected by random-digit dialing (RDD), throughout the state. CHIS develops samples for each of 44 geographic strata, including 41 single-county strata and 3 multiple-county strata; two large counties also include several subcounty strata. Data files include samples for each geographic stratum. Households are selected for participation through random-digit dialing sampling of landline phones and cell phones. In each household, one adult (aged 18 or over) is randomly sampled for interview. In addition, in households with children, one child (through age 11) is randomly sampled and the most knowledgeable parent is interviewed, and one adolescent (aged 12–17) is sampled and directly interviewed (after obtaining parental permission).
The CHIS collects information on asthma (diagnosis, asthma symptoms, emergency room visits, and control and management of asthma), diabetes (pre-diabetes or borderline diabetes, diagnosis, and management of diabetes), and heart disease (heart attacks, heart failures, congestive heart failure, and control and management). Information is also collected on conditions and behaviors associated with these diseases, such as diet, physical activity, and smoking. Information is collected on access to and use of health care, including health insurance coverage, usual source of care, doctor visits, delays in getting care, medical home, communication problems with doctor, and long-term care. CHIS questions are typically drawn or adapted from the NHIS, BRFSS, and other national surveys.
The survey also collects detailed sociodemographic information, including age, sex, detailed race/ethnicity, marital status, education, employment, household income, veteran status, sexual orientation, citizenship and immigration status, languages spoken at home, and English-language proficiency. Questionnaires are translated and administered in English, Spanish, Mandarin, Cantonese, Korean, and Vietnamese. The sample is designed to collect adequate samples of key racial/ethnic populations and to reflect the geographic and other social diversity of California.
The CHIS is conducted by the University of California–Los Angeles (UCLA) Center for Health Policy Research in collaboration with several government agencies and private foundations that fund it. The center uses multiple approaches to disseminate CHIS data and findings. AskCHIS, a free easy-to-use online data query tool, enables users to tailor detailed descriptive analyses for any CHIS health topic by detailed demographics and geographic locations (//www.chis.ucla.edu). Public-use data files for all years can be downloaded from the CHIS website in SAS, SPSS, and Stata data formats. Confidential CHIS data can be accessed by researchers through the secure CHIS Data Access Center (DAC). Nearly 200 peer-reviewed journal articles have been published using CHIS data. Workshops on data access and use are conducted for community organizations and agencies and for researchers. Further information about the survey is available at //www.chis.ucla.edu.
Ohio Family Health Survey (OFHS) This survey, conducted in 1998, 2004, 2008, and 2009, provides state policy makers with information about the health status, healthcare use, health insurance coverage, and healthcare access of Ohioans at the state and county levels. Special attention is paid to those on Medicaid and the uninsured. OFHS data are used for health policy development within Ohio, and by local jurisdictions in their health planning and policy development. This survey is supported by various government and health agencies in Ohio.
OFHS interviews about 50,000 adults, aged 18 years or older, by telephone and obtains proxy responses for more than 13,000 children, one from each household. Households are randomly selected by RDD to landlines and cell phones. The sample includes 88 county strata and random selection of an adult respondent within each household. Questionnaires are translated and administered in English and Spanish.
The questionnaires include three questions related to heart conditions (heart attacks, coronary heart disease, strokes, and congestive heart failure), three questions on asthma, and five questions on diabetes. Information is obtained about three risk factors: smoking, weight, and height. Additional information is collected on health insurance coverage, coverage for supplemental services (vision, dental, prescriptions, mental health care), healthcare use, access to care, and unmet needs for care. OFHS questions are typically drawn or adapted from the NHIS, BRFSS, and other national surveys.
The survey collects information about demographics (marital status, gender, and education), employment characteristics, and income. Minority groups, such as African Americans and individuals with an Asian or a Latino surname, are oversampled to ensure that minority groups are covered in each county.
Data from the OFHS, which is conducted by the Ohio State University with funding from multiple government agencies, are accessible through public-use data files and confidential research data sets for restricted use. Researchers must contact the Ohio Colleges of Medicine Government Resource Center to obtain permission to use the confidential data sets. Further information about the survey can be found at //grc.osu.edu/ofhs.
Hawaii Health Survey (HHS) The Hawaii Health Survey aims at providing the Hawaii Department of Health, other agencies, and the public with data on health services, programs, and health issues. This survey was originally initiated in 1968 and modeled after the NHIS. Until 1996, interviews had been conducted in person, but in 1996 it became a telephone survey. Hawaii Health Survey data are used in public health policy analysis and development within Hawaii, and by local jurisdictions for which samples are available.
Surveys are conducted annually (since 1968); information is collected from approximately 6,769 adult respondents, aged 18 and older, on behalf of about 20,000 individual household members. Respondents are not randomly selected; an adult who is identified as the most knowledgeable about his or her household is selected for an interview in English about all household members. The sample is adjusted and weighted for subareas of Honolulu (city and county), Hawaii, Kauai, and Maui.
Specific questions related to CVD, COPD, asthma, and/or diabetes include questions on whether the person has been diagnosed as having arthritis, asthma, diabetes, high blood cholesterol, hypertension, or cancer (questionnaires are not publicly available). Other Hawaii Health Service questions include behaviors and risk factors (overweight and obesity), health insurance coverage, child care, access and use of health care, other chronic conditions, mental health, and food insecurity. The survey includes detailed information on age, gender, race/ethnicity, household income, education, and household size. Selected data tables are available online. Public-use data files are not available, although publications of researchers using these data are. Further information about the survey is available at //www.hawaii.gov/health/statistics/hhs/index.html.
Some counties and cities have established their own periodic health surveys. Los Angeles County has conducted periodic surveys of its population, and New York City has gone farther than any other local jurisdiction by developing surveys of adults from all five boroughs as well as a one-time local Health and Nutrition Examination Survey (//www.nyc.gov/html/doh/html/hanes/hanes.shtml). These surveys are designed to meet state and local needs for population health data to guide efforts to address chronic disease and other domains of health disparities.
New York City (NYC) Community Health Survey (CHS) The NYC CHS is a local health survey that collects information on health risk behaviors, health conditions, preventive health practices, and healthcare access, primarily related to chronic disease and injuries. This survey was initiated in 2002 and is conducted annually. NYC CHS data are used for policy development, program evaluation, and advocacy within NYC and at the neighborhood level. They are also used for research and surveillance of racial, ethnic, and other social disparities in health. The survey is funded by the NYC Department of Health and Mental Hygiene. There are no federal funds to support this survey.
The study sample consists of a stratified quota probability sample of households with telephones in the city (approximately 10,000 participants per year). This design uses random-digit dialing to enroll sufficient quotas of participants from different ZIP codes. One adult, age 18–99, per family is randomly selected to participate Interviews are conducted 10 months of the year. Information is collected on self-reported prevalence of hypertension, high cholesterol, diabetes, and asthma, and on aspirin use. Information is also collected on physical activity; nutrition and weight control, including consumption of fruits and vegetables; tobacco use and alcohol consumption; and access to, and use of, healthcare services. Self-reported sociodemographic data are collected, including age, sex, race/ethnicity, nativity, marital status, education, employment, and household income. The large survey size and diverse urban population allow for the ability to examine and describe social disparities in health and health care.
NYC CHS provides annual public-use data files through its website, //www.nyc.gov/doh/mycommunityhealth/, as well as survey instruments and other documentation materials, sets of trend analysis tables for the states and the nation, and sets of demographic-specific tables for estimates of risks and conditions, including bar charts for comparison of areas or survey years. More than 40 peer-reviewed journal articles have been published using NYC CHS data.
Health surveys of the general population provide valuable information about the prevalence and distribution of chronic diseases as well as about associated risk factors that may contribute to them and their consequences. Major strengths are the breadth of information they offer and the ability to achieve representativeness through careful sampling. Such information may be helpful in tracking distributions, changes in rates, and comparisons among subgroups. Population surveys are especially valuable because they are based on nonclinical samples, including people who may not have been included in disease reporting systems or registries. Furthermore, population surveys provide valuable data for analyses of disparities in health and healthcare related to the social characteristics they measure (e.g., race, ethnicity, income, geographic area of residence, and other social characteristics). Comprehensive surveys enable researchers to include in their analyses other issues that may be relevant to chronic diseases, including mental health status, health behaviors, and other health and social factors.
Most population health surveys that collect data on chronic conditions use samples drawn from a general population, but they do not include residents of nursing homes or other institutions, many of whom may have the condition of interest. In-person surveys are widely considered to be most inclusive of the population because they select people based on where they are rather than whether they have a telephone or respond to mail surveys, and because they often have high response rates.
Challenges exist in conducting population health surveys. The high cost of conducting in-person surveys has motivated the use of telephone surveys, which can reach a larger and geographically more dispersed sample at far lower cost per completed interview. As the field of telecommunications has changed in the past two decades, telephone surveys have begun sampling both persons with landlines and those who rely on cell phones. Nonetheless, with call screening technologies widely available and with increasing demands on people’s time, telephone surveys have seen steep declines in response rates, eroding public confidence that they include a truly representative sample of the population. Survey methodologists are struggling to develop modes of survey data collection that cover all relevant sectors of the population, including those more responsive to web-based communication than telephone, as well as persons from all relevant races, ethnicities, income, and education levels.
Good chronic disease surveillance requires valid and reliable measurement of the condition. Many population surveys rely exclusively on respondent self-report to questionnaire items, which is perhaps most valid for measuring many health behaviors, mental health conditions, perceived barriers to accessing health services, and reporting of symptoms. However, surveillance of chronic disease also requires reliable examination and laboratory data, which are expensive to collect within the context of a population survey. Examples of population health surveys that rely on respondent self-report include the NHIS, the YRBSS, the BRFSS, and many comprehensive state and local health surveys, such as the CHIS, the OFHS, and NYC CHS. Examples of population health surveys that employ both in-person clinical and laboratory examinations as well as respondent self-reports are the NHANES, SHOW, and NYC HANES.4
The CDC’s BRFSS and YRBSS are two examples of surveys that have advanced chronic disease surveillance capacity at the state level through the efficient leverage of federal resources, and in some cases they include local sampling. Likewise, dedicated state surveys such as CHIS and the OFHS demonstrate that state and private funds can be harnessed for expanded data collection that is highly responsive to a wide range of local and regional stakeholder needs. Similar synergies are needed to (1) link state and local BRFSS data to data sources that provide neighborhood environmental information; (2) promote coordination of state and local surveys with federal surveys to enhance the comparability of measures and resulting data; (3) support state and local efforts to collect examination and laboratory data as part of population surveys; and (4) increase timeliness of national and state survey data releases. Researchers generally make good use of surveillance survey data when data files are available from the surveys. However, most surveys could usefully expand their dissemination strategies and resources to facilitate and encourage the use of surveillance survey data for policy development and advocacy, particularly at the state and local levels.