Background
To understand the general population's health conditions and risk behaviors and evaluate the effectiveness of projects on health promotion, the Health Promotion Administration (HPA) launched the first Behavioral Risk Factor Surveillance System (BRFSS) in 2007 by referencing to the U.S. BRFSS. This telephone interview survey targets people aged 18 and above in Taiwan, focusing on health issues and behavioral risk factors. Since 2007, BRFSS has been conducted annually to monitor the current status and trends of health conditions and relevant behavior risk factors among people in Taiwan. Due to the increase of mobile phone users in the population, HPA adapted the dual-frame design that combined landline and mobile phones survey in 2021. The HPA has redesigned its survey framework by integrating two previously independent annual telephone surveys—Adult Smoking Behavior Survey (ASBS) and the Behavioral Risk Factor Surveillance System (BRFSS). The redesigned system adopts a biennial cycle, in which tobacco-use surveys are conducted in odd-numbered years and health-promotion behavior surveys in even-numbered years.
To improve representativeness, the survey employs a dual-frame sampling design that combines landline and mobile phone samples. Data collection is conducted through telephone interviews across all four quarters of each year to ensure the timely provision of information needed for policy planning and evaluation.
Aim of the Survey
To monitor the health status of the population, major noncommunicable diseases (NCDs), related health behaviors, exposure to risk factors, health-related knowledge, and the utilization of health services, thereby providing essential evidence for the planning and evaluation of health promotion policies.
Survey Coverage and Target Population
Geographic Coverage
The survey covers all 22 counties and cities in Taiwan, including Kinmen and Lienchiang.
Survey Population
The target population consists of individuals aged 15 and above residing within the survey area. The inclusion and exclusion criteria are outlined as follows:
1.Landline Survey
Individuals are eligible if they reside in any of the 22 counties and cities—including Kinmen and Lienchiang—hold household registration, and live in a household with a landline telephone (including fixed-network numbers). One eligible household member is randomly selected for interview.
The sampling frame excludes telephone numbers belonging to government agencies, military units, hospitals, long-term care institutions, companies, schools, vocational training centers, dormitories, detention centers, and prisons.
2.Mobile Phone Survey
Individuals residing in the 22 counties and cities—including Kinmen and Lienchiang—who possess a personal mobile phone number are eligible for selection. Mobile numbers used exclusively for official or non-personal purposes (e.g., government-issued work phones) are excluded.
Sampling Design
The sampling frame in the landline survey is based on the Chunghwa Telecom residential telephone directory and the National Communications Commission's Code verification and allocation of local exchanges for Fixed Communication Network services as the sampling frame. It was applied the Probability Proportional to Size (PPS) as the sampling method in landline survey.
The sampling is conducted with the Random Digit Dialing (RDD) principle, which selects the prefix firstly, and then randomly selects the last four digits of the telephone numbers with those selected area codes. After phone calls are answered, within-household sampling is conducted to pick up the qualified respondent.
The sampling frame in the mobile phone survey is based on the National Communications Commission's Mobile communication network service user number allocation data. Mobile phone numbers are selected by Random Digit Dialing (RDD). The county's population size selected entries of the last five digits as the sample mobile numbers.
Reference Period for Data Collection
The survey is conducted quarterly each year, with fieldwork generally scheduled for January–March, April–June, July–September, and October–December. The reference period for the survey data is defined by the actual dates on which telephone interviews are completed.
Content of the Survey Questionnaire
This survey is conducted as an anonymous, randomly sampled telephone interview using a structured questionnaire as the data collection tool. Survey modules for each quarter are selected based on policy needs, and the questionnaire is designed accordingly. The survey topics encompass noncommunicable diseases, related health behaviors, exposure to risk factors, and the utilization of preventive and health-care services.
Implementing Agencies
Primary Agency: Health Promotion Administration, Ministry of Health and Welfare.
Supporting Agency: National Police Agency, Ministry of the Interior—165 Anti-Fraud Consultation Hotline, which provides necessary administrative assistance.
Commissioned Unit: A professional telephone survey firm contracted to conduct the interviews.
Data Process and Analysis
To safeguard the rights of respondents and ensure robust data protection, this survey is conducted as an anonymous, randomly sampled telephone interview. The implementation process follows all relevant provisions of the Personal Data Protection Act and the Human Subjects Research Act. All collected data are aggregated for statistical analysis and are not released individually. No respondent can be identified in any survey report, nor can any information be traced back to specific individuals.
The survey data are checked and cleaned before analysis. Post-stratification weighting is applied, and goodness of fit test is used to determine whether the distribution of the respondents in gender, age, and residence matched the target population's characteristics to ensure a good representative of the target population.
Survey Results
Results of the survey are published in the format of survey reports, press releases, and conference or journal papers. Descriptive statistics are accessible from the Statistical yearbook of Health Promotion.