Development of a Food Frequency Questionnaire for the Korea National Health and Nutrition Examination Survey: Data from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

The Korea National Health and Nutrition Examination Survey (KNHANES) is a population-based cross-sectional survey designed to assess the health related behavior, health condition, and nutritional state of Koreans (http://knhanes.cdc.go.kr/). It was conducted as a tri-annual survey for the first 3 cycles, implemented in 1998, 2001, and 2005. Beginning with the 4th cycle of 2007, it was converted to an annual survey. The 2011 data was recently opened to the public, and is free for all researchers who want to use it. The KNHANES provides a rich source of data which are easy to access and can be quickly obtained. Its ethical problems are minimal and there are no adverse effects in conducting the study. Using the KNHANES saves time, money, and personnel that would otherwise be spent collecting data, and provides a larger and higher-quality database beyond the capacity of any one individual researcher. Further, because the study participants are representative of the Korean population, the results have external validity. Therefore, this data is helpful to young investigators. In fact, the portion of submitted articles to the Korean Journal of Family Medicine (KJFM) using the KNHANES as the primary source of data is significant. Specifically, one article in 2007, three articles in 2008, four articles in 2009, three articles in 2010, five articles in 2011, and five articles in 2012 used the KNHANES data as their primary data source, totaling 21 articles (6.2%) among 338 original articles during the previous five years. However, there are several points investigators should keep in mind when using the KNHANES data. First, the KNHANES data are open to the public and there is no systematic process to control the research topic assignment. Many researchers might investigate the same topic simultaneously, especially popular topics like obesity and metabolic syndrome. Before deciding on the study topic, a thorough search of the database like Medline, EMBASE, and the abstracts of related conferences are needed. Once the topic is decided upon, the article should be submitted as soon as possible. Otherwise someone else may publish a similar study from the same dataset before you do. Second, investigators must be familiar with the huge and complex data structure and study design of the KNHANES. Non-response and multi-stage probability sampling should be taken into account by using survey statistics to estimate the data of the whole Korean population. Despite this, lots of studies submitted to KJFM using the KNHANES do not apply sampling weight in their analysis. In such a case the estimated association might be biased and revision is required. Third, the KNHANES is a secondary data source like the Korea Youth Risk Behavior Web-based Survey and the Community Health Survey, and has the same limitations that they have.1) The main purpose of the KNHANES is to produce national statistics, not to answer a specific research question. Therefore, the particular information the investigator wants may not be collected. For these reasons, the dataset should be examined carefully to confirm that it includes the necessary data. There also exists a potential for errors or mistakes in the data, even with its rigorous documents control system. Missing data is also a problem in the KNHANES.2)

The Korea National Health and Nutrition Examination Survey (KNHANES) is a national health survey that is conducted annually to assess the health and and health-related behaviors of Korean population. To utilize KNHANES data to studies of mortality risk factors, the Korea Disease Control and Prevention Agency (KDCA) constructed a database linking KNHANES data to cause-of-death statistics in Statistics Korea, made available to researchers since 2020. The KNHANES data were linked to the Cause of Death Statistics based on resident registration numbers for subjects aged 19 years or older who agreed to link the data. The linkage rate between 2007-2015 National Health and Nutrition Examination Survey and 2007-2019 Cause of Death Statistics was 97.1%. In the linked dataset, the total death rate was 6.6%, of which neoplasms accounted for the highest death rate (32.1%), followed by circulatory system disease (22.7%) and respiratory system disease (11.5%). The linked dataset was made available through the Research Data Center of the KDCA after a review of the research proposal, and will be made available after periodical updates.

The Korea National Health and Nutrition Examination Survey (KNHANES) is a national surveillance system that has been assessing the health and nutritional status of Koreans since 1998. Based on the National Health Promotion Act, the surveys have been conducted by the Korea Centers for Disease Control and Prevention (KCDC). This nationally representative cross-sectional survey includes approximately 10 000 individuals each year as a survey sample and collects information on socioeconomic status, health-related behaviours, quality of life, healthcare utilization, anthropometric measures, biochemical and clinical profiles for non-communicable diseases and dietary intakes with three component surveys: health interview, health examination and nutrition survey. The health interview and health examination are conducted by trained staff members, including physicians, medical technicians and health interviewers, at a mobile examination centre, and dieticians’ visits to the homes of the study participants are followed up. KNHANES provides statistics for health-related policies in Korea, which also serve as the research infrastructure for studies on risk factors and diseases by supporting over 500 publications. KCDC has also supported researchers in Korea by providing annual workshops for data users. KCDC has published the Korea Health Statistics each year, and microdata are publicly available through the KNHANES website (http://knhanes.cdc.go.kr).

IntroductionCholesterol is an irreplaceable nutrient in pulmonary metabolism; however, studies on high-density lipoprotein cholesterol (HDL-C) levels have shown conflicting results regarding lung function. Therefore, we investigated the association between lung...

PurposeVitamins exert its effect through different isoforms. The isoform conversion phases involved are affected outside factors. Here, we investigated the correlation between serum retinol, α-tocopherol, and serum inflammatory markers using stratified data acquired from 2016 to 2018 Korea National Health and Nutrition Examination Survey (KNHANES).Materials and MethodsThis study was based on data acquired from the 7th edition (2016–2018) of the Korea National Health and Nutrition Examination Survey, consisting of survey data on smoking and alcohol drinking, serum retinol level, serum α-tocopherol level, high-sensitivity C-reactive protein (hs-CRP), and baseline characteristics.ResultsThere was a negative correlation between serum retinol and hs-CRP in alcohol drinking men. There was a negative correlation between serum retinol and hs-CRP in the alcohol-nonsmoking female group. There was a positive correlation between α-tocopherol and hs-CRP in the nonsmoking and alcohol-drinking group. There was a positive correlation between α-tocopherol and hs-CRP in the nonsmoking and alcohol-drinking female group. There was positive correlation between vitamin A and E and metabolic syndrome. The lowest vitamin A level was observed in subjects with all five metabolic syndrome criteria matched.ConclusionThere was a negative correlation between serum retinol and hs-CRP and positive correlation between α-tocopherol and hs-CRP. Absorption and secretion of serum retinol are affected by inflammation status through retinol-binding protein. Alcohol acts as a competitive inhibitor of vitamin A oxidation through alcohol dehydrogenase and ALDH activity. Smoking causes inflammation and induces reactive oxygen species scavenging system and increases cytochrome p450 levels. These factors may have contributed to the observed findings. Metabolic syndrome subjects increased as the levels of vitamin A and vitamin E increased. Since obesity is inversely related to ALDH activity, we postulate that patients with metabolic syndrome may also have low ALDH activity, especially in the Asian population. Future studies are warranted to study the efficacy of ALDH or ALDH inducers in patients with vitamin A deficiency or metabolic syndrome.

Objective: Muscle mass plays an important role in healthy aging among elderly adults. We investigated the association between dietary patterns and appendicular skeletal muscle mass (ASM) among 3,488 adults ages 60 years or older.Methods: The Korea National Health and Nutrition Examination Survey (KNHANES) data for 2008–2011 were analyzed. Dietary information from a food frequency questionnaire was utilized. To identify dietary patterns, factor analysis was performed. Dual-energy x-ray absorptiometry was used to ascertain ASM. To examine the association between dietary patterns and ASM, a multivariable regression model was used after adjusting for potential confounding factors.Results: Two dietary patterns were identified: Healthy and Western dietary patterns. The Healthy dietary pattern was characterized as high frequencies of intake in vegetables, fish, fruits, seaweeds, legumes, mushrooms, whole grains, potatoes, eggs, dairy products, and red meat. In contrast, the Western dietary pattern was characterized by high intake of red meat, bread, noodles, fast food, rice cake, poultry, and soft drinks. Men showed a significant association between the Healthy dietary pattern and higher ASM, even after adjusting for covariates (p value =0.034).Conclusion: In this cross-sectional study, we observed that men ages 60 years and older with the Healthy dietary pattern had higher muscle mass.

BackgroundTo evaluate and analyse the factors associated with health-related quality of life (HR-QoL) in the Korean population aged 50 years and older.MethodsWe used data obtained from the fourth and fifth Korea National Health and Nutrition Examination Survey (KNHANES IV-V) 2007–2012, a national, cross-sectional health examination and survey, for which representative data on the health, nutritional status, and physical activities of the Korean general population are collected by the Korea Centres for Disease Control and Prevention (KCDC). The sampling protocol for the KNHANES was designed to involve a complex, stratified, multistage probability cluster survey of a representative sample of the noninstitutionalized civilian population in South Korea using a cross-sectional design. The association between HR-QoL and socio-economic factors and medical comorbidities in adults aged 50 years and older was investigated using data from the KNHANES IV-V from 2007 to 2012 (n = 17,937). The EuroQol 5-Dimension Questionnaire (EQ-5D) was used to evaluate HR-QoL, and the factors associated with HR-QoL were analysed after adjusting for socio-economic and demographic factors, anthropometric measurements and clinical comorbidities.ResultsHealth status declined with ageing, and low socio-economic status had negative associations with health status. Gender had no association with health status. Among chronic medical conditions, arthritis and depression had significant associations with health status in older people when stratified by age and gender (P < 0.05).ConclusionsThese findings suggest that older people may value the ability to perform daily activities, which may mean that it is necessary to pay more attention to the factors associated with musculoskeletal pain and emotional distress, as well as socio-economic status or chronic diseases.Trial registrationThe Korea National Health and Nutrition Examination Survey (KNHNES) is not a clinical trial registry, but the national health survey conducted by the Government of the Republic of Korea, to gather information on health and nutritional status of Korean population, to plan public health services and health education programs, and to do statistical studies of the efficiency of public health services required for setting up welfare and healthcare policies.

The purpose of this study was to compare the child car safety and the rate of accidents among Koreans and in order to provide base data for development of education and intervention programs aimed at preventing and managing transportation-related injuries. The numbers of subjects were 7,277 from the Korea National Health and Nutrition Examination Survey in 2013. SPSS 22 was used for statistical analysis with complex sample survey modules and commands. As a result, the rate that didn't use the front seat of the car for child at all was 32.7%, and the rate that had always used child protection equipment in the car was 35.3%. There were significant differences between child car safety consciousness and incidence of injuries(=26.19, p=.014). Appropriate child restraint use was defined as a forward facing child restraint or booster seat for children aged 6 years or less. In this study, the incidence of injuries was the highest Received (September 25, 2015), Review Result(October 15, 2015) Accepted(October 29, 2015), Published(October 31, 2015) 565-701 Dept. Nursing, Woosuk Univ., Samnyero, Samnye-eup, Wanju-gun, Jeonbuk, Korea email: hschoi@woosuk.ac.kr Child Car Safety and Incidence of Injuries in South Korea: Analysis of Korea National Health and Nutrition Examination Survey (K-NHANES) Linked Data Copyright c 2015 HSST 550 inappropriate child restraint use group (10.8%). Therefore, to increase child car safety consciousness, safety education and related program for adults is needed. Moreover, child passenger safety campaign and law remedy for child safety in the car should be strengthened.

Prevalence of chronic kidney disease and anemia among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort Study: Baseline results

Background and Objectives: This study aimed to investigate the association between insulin resistance, as measured by the triglyceride–glucose index (TyG index), and hearing impairment in middle-aged women in Korea. Materials and Methods: This cross-sectional survey utilized data from the Korea National Health and Nutrition Examination Survey (KNHANES) IV (2007–2009), specifically from the period after July 21, 2009, when hearing test results became available, and from the KNHANES V (2010–2012). This study was conducted on 5416 women aged 40 to 69 who had completed both the health examination survey and audiometric tests, excluding those with missing data on menopausal status and the use of hormone replacement therapy. Results: In the study group, the prevalence of high-frequency hearing loss according to the TyG index was significantly higher in the mild hearing loss group (OR = 1.29; 95% CI: 1.12, 1.49, p &lt; 0.001) and the moderate hearing loss group (OR = 1.27; 95% CI: 1.09, 1.48, p = 0.002). Conversely, the prevalence of low-frequency hearing loss did not show a significant difference in either the mild hearing loss group (OR = 1.17; 95% CI: 0.99, 1.37, p = 0.065) and the moderate hearing loss group (OR = 1.13; 95% CI: 0.94, 1.35, p = 0.199) Conclusions: Since diabetes can induce hearing impairment in women, it is recommended that women with a high TyG index undergo early hearing tests

OBJECTIVESIn South Korea, there are two nationwide health surveys conducted by the Korea Centers for Disease Control and Prevention: the Korea Community Health Survey (KCHS) and Korea National Health and Nutrition Examination Survey (KNHANES). The two surveys are directly comparable, as they have the same target population with some common items, and because both surveys are used in various analyses, identifying the similarities and disparities between the two surveys would promote their appropriate use. Therefore, this study aimed to compare the estimates of six variables in KCHS and eight variables in KNHANES over a six-year period and compare time series stability of region-specific and sex- and age-specific subgroup estimates.METHODSData from adults aged 19 years or older in the 2010-2015 KCHS and KNHANES were examined to analyze the differences of estimates and 95% confidence interval for self-rated health, current smoking rate, monthly drinking rate, hypertension diagnosis rate, diabetes diagnosis rate, obesity prevalence, hypertension prevalence, and diabetes prevalence. The variables were then clustered into subgroups by city as well as sex and age to assess the time series stability of the estimates based on mean square error.RESULTSWith the exception of self-rated health, the estimates taken based on questionnaires, namely current smoking rate, monthly drinking rate, hypertension diagnosis rate, and diabetes diagnosis rate, only differed by less than 1.0%p for both KCHS and KNHANES. However, for KNHANES, estimates taken from physical examination data, namely obesity prevalence, hypertension prevalence, and diabetes prevalence, differed by 1.9-8.4%p, which was greater than the gap in the estimates taken from questionnaires. KCHS had a greater time series stability for subgroup estimates than KNHANES.CONCLUSIONSWhen using the data from KCHS and KNHANES, the data should be selected and used based on the purpose of analysis and policy and in consideration of the various differences between the two data.

ObjectivesThe effect of breastfeeding on periodontal disease in women remains unclear. This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey to explore the association between breastfeeding and periodontitis in Korean women using data from the Korean National Health and Nutrition Examination Survey (KNHANES VII).Materials and methodsCross-sectional data was analyzed from the KNHANES 2016–2018. The study population included 5,587 parous women aged ≥ 30 years. The outcome variable was the presence or absence of periodontitis. The explanatory variable, period of breastfeeding, was defined as “none”, “1–11 months”, and “more than 12 months”. Confounder variables (socio-educational, personal healthcare practice, and systemic medical characteristics) were adjusted for in the logistic regression analysis.ResultsApproximately 60% of the participants breastfed for ≥ 12 months. In all statistical models, the prevalence of periodontitis was approximately 60% greater in women that did not breastfeed compared to women that had breastfed for 12 months or longer. When adjusted for age, statistical significance was only present in the 50–59 years age group (adjusted odds ratio [aOR], 1.678; 95% confidence interval [CIs], 1.046–2.691).ConclusionOur study shows that women that breastfed for a relatively long duration had a lower risk of periodontitis. Therefore, breastfeeding may be beneficial for women’s periodontal health. These results are expected to be helpful in oral health education for pregnant women.

Kim, YK, Lee, HB, and Lee, SH. Trends in mean hand grip strength, cutoff value, and prevalence of low hand grip strength: An analysis of 2014-2019 Korea National Health and Nutrition Examination Survey (KNHANES) data. J Strength Cond Res 39(8): e967-e973, 2025-The European Working Group on Sarcopenia in Older People 2 (EWGSOP2) defines probable sarcopenia as low muscle strength detected by hand grip strength (HGS). According to this guideline, cutoff for low HGS is determined using a T -score of -2.5 based on age group showing the highest HGS (aged 30-39 years). Our hypothesis is that temporal changes in mean HGS of Koreans may lead to changes in the cutoff values for low HGS and the prevalence of probable sarcopenia as defined by the EWGSOP2 guidelines. We analyzed trends of HGS using 6 years of Korea National Health and Nutrition Examination Survey data. We used the EWGSOP2 guidelines to set yearly cutoff values for low HGS and calculated the prevalence of low HGS. The cutoff value for low HGS and the prevalence rate of low HGS in individuals aged 70 years or older were analyzed using linear regression and trend analysis. We observed a significant decreasing trend from 2014 to 2019 in annual cutoff values for low HGS, ranging from 24.5 to 30.9 kg in men and 13.1-17.3 kg in women. Correspondingly, the prevalence of low HGS (probable sarcopenia) varied significantly from 10.4 to 34.2% in men and 9.1-20.8% in women, indicating notable year-to-year fluctuations ( p < 0.001). While pooling multiyear data reduces some variability, it does not fully address fluctuations in prevalence of probable sarcopenia. To enhance the reliability and clinical relevance of low HGS cutoff values, future guidelines should integrate outcome-based criteria with normative data, ensuring adaptability to temporal trends and population-specific characteristics.

The Korea National Health and Nutrition Examination Survey (KNHANES) is a representative survey of the Korean population, providing evidence for health policy and health interest statistics. The survey is conducted annually, and the 10th cycle, 1st year (2025) survey is currently underway. In health examination of KNHANES, blood samples are collected from people aged 10 years or older, and urine samples are collected from people aged 6 years or older. To support research related to various public health concerns based on the general population, the National Bank of Korea (NBK) has been operating the KNHANES biobank project since 2005 and has distributed high-quality biospecimens collected through KNHANES. To date, biospecimens from a total of 95,455 participants have been deposited, with approximately 35,500 biospecimens available as of December 2024. This biobank provides serum, plasma, and extracted DNA to researchers in officially approved projects. Recently, urine specimens have also become available. Additionally, genotyping data (> 833,000 genetic markers) for ~19,300 participants generated from the KoreanChip are available. The vast epidemiological data linkage derived from KNHANES will provide valuable insights into public health issues. Researchers can access the resource through NBK’s online platform (HuBIS_Desk, https://biobank.nih.go.kr/Desk/).

Hepatitis C Virus Genotypes and Viral Concentrations in Participants of a General Population Survey in the United States