Korea Nurses' Health Study and the health of reproductive-aged women: a cohort profile.

The Korea Nurses' Health Study (KNHS) is an ongoing, large-scale, prospective cohort study of female nurses, focusing on the effects of occupational, environmental, and lifestyle factors on the health of women. The first KNHS survey was performed in 2013-2014 (n=20,613). As of December 2023, 11 follow-up surveys have been conducted. Participants who were pregnant were asked to participate in the early pregnancy survey (n=2,179) and postpartum survey after giving birth (n=2,790). The main variables included sociodemographic, work-related, lifestyle, physical, mental, and women's health factors. Blood, urine, and toenail samples were collected from a participant subgroup of the first survey (n=1,983). The subgroups of the second survey completed a food frequency questionnaire in 2019 (n=300) and 2021 (n=871). In 2020, a subgroup of the first survey answered a coronavirus disease 2019 (COVID-19)-related survey (n=975). To examine various health-related factors in young adults, new participants were added to the KNHS cohort in the 11th (n=1,000) and 12th (n=1,002) surveys. The KNHS cohort will help identify health and illness determinants in Korean women. Data can be accessed at https://coda.nih.go.kr/frt/index.do.

Development of a Tool to Measure Compliance with Infection Prevention Activities Against Emerging Respiratory Infectious Diseases among Nurses Working in Acute Care and Geriatric Hospitals.

BACKGROUND: This study developed a preliminary instrument to measure nurses' infection prevention compliance against emerging respiratory infectious diseases and to verify the reliability and validity of the developed instrument. METHOD: The participants were 199 nurses working at a university hospital with more than 800 beds and two long-term care hospitals. Data were collected in May 2022. RESULTS: The final version of the developed instrument consisted of six factors and 34 items, with an explanatory power of 61.68%. The six factors were equipment and environment management and education, hand hygiene and respiratory etiquette, infection risk assessment and flow management, protection of employees in contact with infected patients, ward access management of patients with infectious diseases, and wearing and removing personal protective equipment. We verified the convergent and discriminant validities of these factors. The instrument's internal consistency was adequate (Cronbach's α=0.82), and the Cronbach's α of each factor ranged from 0.71 to 0.91. CONCLUSION: This instrument can be utilized to determine the level of nurses' compliance with infection prevention activity against emerging respiratory infectious diseases and will contribute to measuring the effectiveness of future programs promoting infection-preventive activities.

Body mass index, menstruation, acne, and hirsutism of polycystic ovary syndrome in women: A cross-sectional study.

We examined to compare menstruation and body mass index (BMI) in women with and without polycystic ovary syndrome (PCOS) and to explore the effects of BMI on menstruation, facial acne, and hirsutism in women with PCOS of child-bearing age. Data from the Korea Nurses' Health Study were analyzed. The effect of BMI on irregularity of menstruation, acne, and hirsutism in the PCOS group was analyzed by logistic regression. The prevalence of PCOS was 7.1% among 11,866 participants. We found that BMI affects menstrual irregularity, facial acne, and hirsutism in PCOS women. Healthcare providers should consider weight control to improve irregularity of menstruation and hirsutism in PCOS women.

Vitamin D deficiency and associated factors in south Korean childbearing women: a cross-sectional study.

BACKGROUND: Adequate levels of vitamin D are important for women of childbearing age as vitamin D helps maintain the pregnancy and ensures proper maternal and fetal bone metabolism and fetal skeletal development. However, vitamin D deficiency is a health problem prevalent in women of all ages, worldwide. This study aimed to determine the current status of serum vitamin D levels and the risk factors for vitamin D deficiency among South Korean nurses of childbearing age. METHODS: Serum levels of 25-hydroxyvitamin D (25[OH]D) were measured in 1594 registered nurses aged 20 to 45 years who are participants in an ongoing prospective cohort study of the Korean Nurses' Health Study initiated in 2013. The participants completed surveys about demographic and occupational characteristics and physical and psychological health. We examined associations with vitamin D deficiency through multivariable logistic regression analysis. RESULTS: The average blood 25(OH) D concentration of the participants was 12.92 ng/mL (4.0-63.4 ng/mL), while the prevalence of vitamin D deficiency (< 20 ng/mL) was 89% (1419/1594). Multivariable logistic regression showed that significant risk factors for vitamin D deficiency included month of sampling (there was a lower level of vitamin D deficiency in winter than in spring, summer, or fall), age (women in their 20s had a lower vitamin D level than those in their 30s and 40s), and stress symptoms. Vitamin D levels were not associated with body mass index, physical activity, and depressive symptoms. CONCLUSIONS: This study showed a high prevalence of vitamin D deficiency in Korean female nurses. Serum levels of vitamin D were associated with age and season. Vitamin D deficiency should be recognized as one of the primary health concerns among young women. More proactive actions, such as vitamin D supplements and food fortification, are needed to improve vitamin D deficiency in high-risk groups.

Sleep, Fatigue, and Depressive Symptoms among Female Nurses with Allergic Rhinitis.

Allergic rhinitis (AR) is a common chronic disease that negatively affects physical and mental health. The purpose of this study was to determine the effects of allergic rhinitis on sleep, fatigue, and depressive symptoms among Korean female nurses. This was a cross-sectional study conducted using data from the Korea Nurses' Health Study (KNHS), and a total of 8645 female nurses was selected for the final analysis. The demographic characteristics, Body Mass Index, alcohol consumption, shift work, comorbidities (atopic dermatitis and asthma), self-rated health, sleep disturbance (Jenkins Sleep Questionnaire), fatigue (Chalder Fatigue Scale), and depressive symptoms (Perceived Health Questionnaire-9) were collected. The data were analyzed using chi-square tests, t-tests, and hierarchical multiple regression analyses. Participants with allergic rhinitis had significantly greater sleep disturbance, fatigue, and depressive symptoms than those without allergic rhinitis, and allergic rhinitis was a significant factor influencing sleep disturbance and fatigue among the participants after controlling for confounding variables. Therefore, it is imperative to develop effective interventions to manage allergic rhinitis symptoms and improve sleep and fatigue in affected nurses.

Prediction model for abnormal eating behaviour among hospital nurses: A structural equation modelling approach.

BACKGROUND: Nurses are at a high risk of developing abnormal eating behaviour. However, few studies have attempted to identify the factors that influence such behaviour. AIM: This study identifies factors that can predict abnormal eating behaviour in hospital nurses. DESIGN: This study adopted a cross-sectional, descriptive correlational research design. METHODS: A literature review was used to establish a hypothetical model, comprising the eight factors of shift work, job stress, depression, sleep quality, fatigue, coping strategy (active coping and passive coping) and abnormal eating behaviour. A convenience sample of 298 nurses aged less than 45 was recruited from two university hospitals, and structured questionnaire was administered between March and April 2017. The hypothesized model was tested using structural equation modelling. RESULTS: Sleep quality and passive coping directly affect abnormal eating behaviour, which implies that poor sleep quality and increased passive coping worsens the behaviour. Shift work and depression indirectly affect abnormal eating behaviours. CONCLUSION: Nursing managers and health policy makers should adopt strategies such as improving the shift-work pattern, providing adequate rest time after a night shift and enabling coping strategies by providing educational programs for hospital nurses.

Correlations among anti-Müllerian hormone levels, body mass index and lipid profile in reproductive-aged women: The Korea Nurses' Health Study.

AIM: This study aimed to evaluate the correlations among anti-Müllerian hormone levels, body mass index and lipid profile in female nurses of reproductive age. DESIGN: This is a descriptive cross-sectional study that used data from the Korea Nurses' Health Study, based on Nurses' Health Study 3 in the United States. METHODS: Participants included 448 female nurses of reproductive age. They provided details about their work experience, shift work, body mass index and history of polycystic ovary syndrome. Serum anti-Müllerian hormone levels and lipid profile were measured using blood samples. Statistical analysis included quantile regression analysis using STATA 13.0. Data were collected between November 2016 and March 2017 from Module 5 of the Korean Nurses' Health Study. RESULTS: Approximately 12% of the participants were underweight, and roughly one-tenth were either overweight or obese. Although linear regression showed no relationship between anti-Müllerian hormone levels and body mass index, quantile regression showed that body mass index, total cholesterol levels and low-density lipoprotein levels were negatively correlated with anti-Müllerian hormone levels at the lower tails of the dependent variable. Meanwhile, high-density lipoprotein levels were positively correlated with anti-Müllerian hormone at the higher percentiles of anti-Müllerian hormone levels. CONCLUSION: These findings suggest the possibility that changes in the lipid profile may influence anti-Müllerian hormone levels in women with diminished ovarian function, rather than obesity itself.

Predictors of actual turnover among nurses working in Korean hospitals: A nationwide longitudinal survey study.

AIM: To examine the factors affecting actual turnover among nurses working in hospitals using the Brewer-Kovner synthesis model. BACKGROUND: To increase retention of nurses, it is important to understand factors contributing to actual turnover among nurses. METHODS: A longitudinal study design was utilized with 2,633 of 20,613 eligible female hospital nurses who participated in Korea Nurses' Health Study. We created two age groups: a younger group (20-35 years) and an older group (36-49 years). Multivariate logistic regression was used to identify the factors influencing turnover by age group. RESULTS: Pregnancy and childbirth increased young nurses' turnover. When we excluded intent to leave, depression and burnout were significant factors affecting young nurses' turnover. Salary and hospital size were factors predicting nurse turnover among nurses older than 36 years. CONCLUSIONS: It is essential to develop prevention strategies of female nurse turnover based on the age group in Korea. IMPLICATIONS FOR NURSING MANAGEMENT: Nurse managers and health care institutes need to develop new managerial and policy strategies to reduce nurse turnover in each age group.

Factors affecting frontline Korean nurses' mental health during the COVID-19 pandemic.

AIM: To identify the factors affecting fear, anxiety and depressive symptoms among frontline nurses working with COVID-19 patients or are in charge of COVID-19 screening in Korea. BACKGROUND: Nurses are at a higher risk of COVID-19 infection because they are in closer, longer-duration contact with patients. These situations can negatively affect the mental health of nurses. METHODS: This study analysed data from COVID-19 module in the Korean Nurses' Health Study. Data from 906 participants were analysed. To identify the factors influencing mental health, descriptive statistics, Pearson's correlation and hierarchical multiple regression analyses were performed. RESULTS: Caring for patients who are COVID-19-positive increased levels of fear, anxiety and depressive symptoms of nurses. The hospital safety climate influenced mental well-being among nurses. CONCLUSION: Caring for patients with COVID-19 had a negative impact on fear, anxiety and depressive symptoms. However, the higher was the perceived hospital safety climate, the lower were the nurses' psychological symptoms. Further research on the mental health of nurses is warranted. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Institutions should manage human resources to enable periodic rotation of nurses' work and working periods related to COVID-19. In addition, hospital managers should provide sufficient personal protective equipment, related education, and safety climate.

Use of Menstrual Sanitary Products in Women of Reproductive Age: Korea Nurses' Health Study.

OBJECTIVES: The use of menstrual hygiene products and its effect on women's health remains under studied. Patterns of menstrual hygiene product use and the rationale behind choices among Korean women aged 18-45 years were examined. METHODS: This cross-sectional study was a part of the Korea Nurses' Health Study. A total of 20,613 nurses participated, and 8,658 nurses participated in Module 7 which included a menstrual hygiene products-related survey. The data were collected through the mobile survey using a self-reported questionnaire. Participants' use of menstrual hygiene products and related characteristics were analyzed using frequency (percentage) or mean (SD). RESULTS: The most common types of menstrual hygiene products across all age groups were disposable menstrual pads (89.0%), followed by cloth menstrual pads (4.5%), tampons (4.2%), and only 1.6% used a menstrual cup. Disposable menstrual pads were the most common across all age groups, but in those aged under 30 years this was followed by tampon use (6%). The most important criteria when choosing a menstrual hygiene product was comfort for disposable menstrual pads (31.3%) and tampons (41.5%), natural ingredients or organic products for cloth menstrual pads (51.4%), and custom fit for the menstrual cup (50.7%). However, for all menstrual hygiene products (except cloth menstrual pads), there was a higher proportion of anxiety than perception of safety, and low awareness of toxic shock syndrome. CONCLUSION: It is important for women to use menstrual hygiene products with confidence. More research is needed to better understand potential health effects of menstrual hygiene products.

Factors Affecting Physical and Mental Fatigue among Female Hospital Nurses: The Korea Nurses' Health Study.

Nurses often experience work-related physical and mental fatigue. This study sought to identify the levels of physical and mental fatigue present among Korean female nurses and discern factors influencing their onset. This cross-sectional study analyzed data from the Korea Nurses' Health Study (KNHS). A total of 14,839 hospital nurses were assessed by hierarchical regression analysis. The mean scores of physical and mental fatigue were 12.57 and 5.79 points, respectively. After adjusting for confounding variables, the work department had a significant influence on both physical and mental fatigue, that is, nurses working in special care units experienced greater degrees of both physical and mental fatigue than those working in general units. Nurse fatigue is an important consideration to monitor to ensure nurses' continued wellbeing as well as good patient safety levels. Therefore, it is necessary to establish a strategy to mitigate nursing fatigue while considering the characteristics of specific departments. In nursing practice, the introduction of a counseling program and guarantee of rest time that can alleviate the mental and physical fatigue of nurses working in special care units should be considered.

Association between Dietary Habits, Shift Work, and the Metabolic Syndrome: The Korea Nurses' Health Study.

Metabolic syndrome (MetS) is an important public health problem, and unhealthy dietary habits and shift work are considered major factors that increase the prevalence of MetS. The purpose of this study was to examine whether dietary habits, alcohol drinking, and shift-working were associated with development of MetS in shift-working female nurses. This study analyzed cross-sectional survey data from the Korea Nurses' Health Study (KNHS). Of the 1638 nurses, 403 participants were selected based on the propensity score matching method (PSM). These participants had either no or more than three MetS determinant factors. Analysis was conducted by using multivariable logistic regression to confirm the factors influencing MetS. The prevalence of MetS in this group (1638 participants) was 5.6% (92 participants). Consumption of over 50% of daily calorie intake after 7 p.m., consumption of carbonated drinks, family history of diabetes, and non-shift work were significant factors influencing MetS. Nurses are one of the at-risk groups for unhealthy dietary habits due to the nature of their work. Therefore, nurse managers should include regular dietary education for nurses and continue their policy efforts to resolve health problems that may arise in connection with nurses' work.

Depressive Symptoms and Sleep Disturbance in Female Nurses with Atopic Dermatitis: The Korea Nurses' Health Study.

Although the prevalence of atopic dermatitis is high in nurses, there is a lack of research on the relationship between atopic dermatitis and depressive symptoms and sleep disturbance among female nurses. This study aimed to determine the effects of atopic dermatitis on depressive symptoms and sleep disturbance in female nurses. We analyzed the data of the Korea Nurses' Health Study, a large-scale prospective cohort study. A total of 20,613 female hospital nurses aged 20-45 years who participated in the Module 1 of Korea Nurses' Health Study between July 2013 and November 2014 were included. The chi-square test, t-test, and multivariate ordinal logistic regression analysis were conducted for statistical analysis. The prevalence of atopic dermatitis among female nurses was 11.6%. The levels of depressive symptoms and sleep disturbance were higher in nurses with atopic dermatitis than those without atopic dermatitis. Nurses with atopic dermatitis were 1.16 times more likely to have depressive symptoms and 1.35 times more likely to have sleep disturbance than those without atopic dermatitis after adjusting for confounding variables. The results of this study suggest that additional support should be considered for nurses with atopic dermatitis to improve the occupational environment for managing and preventing the exacerbation of symptoms.

Assessing the Presence of Post-Traumatic Stress and Turnover Intention Among Nurses Post-Middle East Respiratory Syndrome Outbreak: The Importance of Supervisor Support.

Background: South Korea faced the Middle East Respiratory Syndrome (MERS) outbreak for the first time in 2015, which resulted in 186 infected patients and 39 deaths. This study investigated the level of post-traumatic stress disorder (PTSD) and turnover intention, the relationship between PTSD and turnover intention, and the buffering effect of supervisor support among nurses post-MERS outbreak. Methods: In total, 300 nurses from three of 15 isolation hospitals in South Korea were invited to participate. We collected data pertaining to PTSD, turnover intention, supervisor support, work-related factors, and socio-demographic factors through a structured survey distributed to the nurses at the hospitals after the outbreak. For the statistical analyses, descriptive statistics and multiple regression were employed. Findings: Of the 147 participants, 33.3% were involved in the direct care of the infected patients, whereas 66.7% were involved in the direct care of the suspected patients. More than half (57.1%) of the nurses experienced PTSD, with 25.1% experienced full PTSD and 32.0% with moderate or some level of PTSD. The mean score of turnover intention was 16.3, with the score range of 4 to 20. The multiple regression analysis revealed that PTSD was positively associated with turnover intention, and supervisor support had a strong buffering effect. Conclusion/Application to Practice: These findings confirmed that after a fatal infectious disease outbreak like MERS, nurses experience high level of PTSD and show high intention to leave. Organizational strategies to help nurses to cope with stress and to prevent turnover intention, especially using supervisor support, would be beneficial.

Korean nurses' adherence to safety guidelines for chemotherapy administration.

PURPOSE: Nurses are at risk from handling chemotherapeutic agents. This study aimed to determine adherence to safety guidelines for chemotherapy administration by Korean nurses and to examine the relationship between the hospital safety climate and nurses' adherence to safety guidelines. METHOD: A descriptive, correlational design with a cross-sectional survey using data from the Korea Nurses' Health Study. For this study, participants included 872 female nurses who had administered chemotherapeutic agents to patients in the last 30 days. RESULTS: Only a quarter of the participants had high adherence to the safety guidelines, while the majority had moderate to low adherence. The absence of job hindrances and feedback/training - two sub-factors of the hospital safety climate - enhanced the likeliness for nurses to comply with the safety guidelines by almost 1.3 and 1.7 times, respectively. CONCLUSION: The results imply that the hospital safety climate, particularly feedback/training, and the absence of job hindrances are significantly correlated with adherence to the safety guidelines for chemotherapy administration. Therefore, organisational and policy support is needed to improve the hospital safety climate.

Gastroesophageal reflux disease and its related factors among women of reproductive age: Korea Nurses' Health Study.

BACKGROUND: Recently, the number of patients diagnosed with gastroesophageal reflux disease (GERD) has increased in Korea. Risk factors of GERD include age, sex, medication use, lack of physical exercise, increased psychological stress, low or high body mass index (BMI), unhealthy eating habits, increased alcohol consumption, and cigarette smoking. However, few studies examined the major factors affecting GERD in women of childbearing age. Therefore, this study assessed the risk factors of GERD among 20,613 female nurses of reproductive age using data from the Korea Nurses' Health Study. METHODS: Participants were recruited from July 2013 to November 2014. They provided their history of GERD 1 year prior to data collection, along with information on their demographic characteristics, health-related behaviors, diet, medical history, and physical and psychological factors. Of the total sample, 1184 individuals with GERD diagnosed in the year prior to the study were identified. Propensity score matching was used for analysis. RESULTS: Cigarette smoking, increased alcohol consumption, low or high BMI, depression, and increased psychosocial stress were associated with the prevalence of GERD among Korean young women. Multivariate ordinal logistic regression analysis revealed significant positive relationships between GERD and being a former smoker; having a low (< 18.5 kg/m2) or high BMI (> 23 kg/m2); and having mild, moderate, moderately severe, and severe depression. CONCLUSIONS: Smoking, BMI, and depression were associated with GERD. To reduce this risk among female nurses, intervention strategies are required to help nurses maintain a normal weight and manage their depression.

Weight change and risk of uterine leiomyomas: Korea Nurses' Health Study.

OBJECTIVE: This study examined the associations between anthropometric measures and uterine leiomyomas. METHODS: This study included a total of 5,062 women (median age of 35.5 years) who had experienced pregnancy and, of these women, 210 reported a diagnosis of uterine leiomyomas within the past 2 years prior to baseline in the Korea Nurses' Health Study. Participants were asked about their anthropometric factors. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression models. RESULTS: Mean body mass index (BMI) was 21.8 kg/m2 among non-cases. An increase in weight from the age of 18 years to the present was associated with increased risk of uterine leiomyomas (p for trend = .002); compared to women whose weight remained stable, the multivariate ORs (95% CIs) were 1.84 (1.22-2.76) for weight gain of 5-10 kg and 2.00 (1.25-3.20) for weight gain of more than 10 kg since age 18. A similar pattern was observed when the analysis was limited to women with a BMI of 18.5-25 kg/m2. Current weight was associated with higher odds of uterine leiomyomas. No associations were found for body size in childhood or in adolescence, weight at age 18, current BMI, or current body size. CONCLUSIONS: Weight gain in adulthood was associated with increased risk of uterine leiomyomas in Korean women, even in those with normal weight.

Radiation safety education and compliance with safety procedures-The Korea Nurses' Health Study.

AIMS AND OBJECTIVES: To examine the current state of radiation safety education and its influence on nurses' compliance with safety procedures. BACKGROUND: Use of radiation in therapy and diagnosis has prolonged and improved millions of lives, but it presents potential hazards for healthcare professionals. DESIGN: A cross-sectional design. METHODS: Participants included 1,672 female nurses of childbearing age who had recently been exposed to radiation-emitting generators or radiation. Quantitative data were taken from the Korea Nurses' Health Study, the Korean version of the Nurses' Health Study conducted in the USA. Confounding variables included sociodemographic factors, duration of employment in a department where work involved radiation, hospital's geographical location, bed size and hospital safety climate. Statistical analyses included descriptive statistics, Spearman's correlation coefficients and multivariable ordinal logistic regression. RESULTS: Half (50.3%) of nurses received no safety training, whereas the other half received some safety training as follows: only once (14.4%), irregularly (10.2%) and regularly (25.1%). Of the six radioactive safety compliance questionnaires, 29.4%, 20.2%, 30.7% and 19.7% complied to none, one, two and more than three, respectively. After controlling for confounding variables, relative to that observed with no safety education, irregular education that occurred more than twice (OR = 1.597, CI = 1.177-2.164) and regular education (OR = 2.223, CI = 1.770-2.792) increased the likelihood that nurses would comply with safety procedures. CONCLUSIONS: Low levels of safety education and adherence raise critical concerns regarding nurses' well-being. As routine safety education increases safety adherence, healthcare managers and policymakers should emphasise regular safety education. RELEVANCE TO CLINICAL PRACTICE: Radiation safety education for nurses and their compliance with safety procedures have seldom been discussed in South Korea. However, as nurses' safety is directly related to the quality of patient care, additional safety education should be provided for hospital nurses to minimise their occupational exposure to harmful radioactive substances in clinical settings.

The Korea Nurses' Health Study: A Prospective Cohort Study.

BACKGROUND: The Korea Nurses' Health Study (KNHS) is a prospective cohort study of female nurses, focusing on the effects of occupational, environmental, and lifestyle risk factors on the health of Korean women. MATERIALS AND METHODS: Female registered nurses aged 20-45 years and living in the Republic of Korea were invited to join the study, which began in July 2013. They were asked to complete a web-based baseline survey. The study protocols and questionnaires related to the KNHS are based on the Nurses' Health Study 3 (NHS3) in the United States, although they were modified to reflect the Korean lifestyle. Participants were asked about demographic, lifestyle factors, disease history, occupational exposure, reproductive factors, and dietary habits during their adolescence: Follow-up questionnaires were/will be completed at 6-8 month intervals after the baseline survey. If a participant became pregnant, she answered additional questionnaires containing pregnancy-related information. RESULTS: Among 157,569 eligible female nurses, 20,613 (13.1%) completed the web-based baseline questionnaire. The mean age of the participants was 29.4 ± 5.9 years, and more than half of them were in their 20s. Eighty-eight percent of the participants had worked night shifts as a nurse (mean, 5.3 ± 4.3 nights per month). Approximately 80% of the participants had a body mass index below 23 kg/m2. Gastrointestinal diseases were the most prevalent health issues (25.9%). CONCLUSIONS: The findings from this prospective cohort study will help to identify the effects of lifestyle-related and occupational factors on reproductive health and development of chronic diseases in Korean women.