A Population-Based, Nationwide Cross-Sectional Study on Influenza Vaccination Status among Cancer Survivors in Korea

Vaccination uptake among post-treatment cancer survivors: A multi-vaccine scoping review

BACKGROUND

Our goal was to provide an overview of uptake rates across vaccine types and factors associated with vaccine uptake among cancer survivor populations.

METHODS

A literature search was conducted using Ovid MEDLINE® ALL (Wolters Kluwer), Embase (Elsevier) and CINAHL Complete (EBSCO) databases and according to PRISMA guidelines. Eligible articles were limited to those examining vaccination uptake among cancer survivors who had completed treatment, reported factors associated with uptake (e.g., barriers and facilitators), and published in English between 2011 and 2021. Two independent reviewers screened citations for inclusion and two performed data abstraction, verified by an arbiter.

RESULTS

The search returned 4,215 total articles, and 271 duplicates were removed. During abstract/title screening, 212 articles were identified. Following full-text screening, 47 articles/abstracts were found to meet inclusion criteria, 16 articles/abstracts were removed, and 31 studies were included in the review. Among the 31 studies, participant age ranged from 9 years to adults of all ages. Vaccine types included: influenza (n = 18), human papillomavirus (n = 10), pneumococcal (n = 8), hepatitis A/B (n = 1), shingles (n = 1), measles (n = 1), tetanus/diphtheria (n = 1), and haemophilus influenza B (n = 1). Vaccine uptake varied greatly across studies, vaccine types, and participant populations. Factors affecting vaccination uptake included sociodemographic variables and social determinants of health, health beliefs/attitudes/knowledge, provider recommendation, and cancer treatment/clinical variables.

CONCLUSIONS

Our findings highlight the need for further examining factors associated with vaccine uptake, the need for clinical guidelines that specifically address vaccination among cancer survivors, and potential targets for multi-level interventions to improve vaccination rates among cancer survivor populations.

The coverage of influenza vaccination and predictors of influenza non-vaccination in Danish cancer patients: A nationwide register-based cohort study

BACKGROUND

Influenza vaccination is recommended and provided free-of-charge to Danish citizens aged ≥65 years and to individuals with acquired immunodeficiency. We aimed to estimate influenza vaccination coverage and investigate predictors of influenza non-vaccination in Danish cancer patients.

METHODS

A nationwide cohort study of all Danish citizens aged ≥18 years with an incident cancer diagnosis between 2002 and 2017. Using national registries, we assessed information on influenza vaccination and potential predictors of influenza non-vaccination. We estimated adjusted prevalence ratios (aPR) of influenza non-vaccination for patients aged <65 years and ≥65 years.

RESULTS

We observed 269,863 patients during 840,876 influenza vaccination seasons. The influenza vaccination coverage was 14 % for cancer patients <65 years and 51 % for those ≥65 years. No influenza vaccination in the previous season was associated with non-vaccination in the current season (<65 years: aPR = 2.75, 95 %CI = 2.71-2.80; ≥65 years: aPR = 5.15, 95 %CI = 5.10-5.21). Haematological cancer patients receiving chemotherapy had lower vaccination prevalence compared with those not receiving chemotherapy.

CONCLUSIONS

The influenza vaccination coverage was low among cancer patients. Influenza non-vaccination in the previous season was the strongest predictor of not receiving influenza vaccination in the current season. Haematological cancer patients on current chemotherapy had lower vaccination prevalence than those not currently receiving chemotherapy.

The role of health determinants in the influenza vaccination uptake among older adults (65+): a scope review

Background

Although the burden of influenza infection is the highest in older adults, vaccination coverage remains low, despite this age group being more vulnerable than others.

Aims

Given the current pandemic of SARS-CoV-2, it was the aim of this scope review to update knowledge on factors affecting seasonal influenza vaccine uptake among older adults to strengthen prevention approaches in the context of an overall burden of infectious diseases.

Methods

We searched bibliographic databases from 2012 to 2019. All studies reviewed one or more social determinant of health listed by WHO, or factors affecting the decision-making process whether to accept influenza vaccine or not.

Results

Overall, 44 studies were included, 41 determinants were extracted and summarized into six categories. Older age and constitutional factors including multiple chronic diseases as well as preventive lifestyle and frequent routine healthcare utilization positively affected vaccination uptake (VU). Living and working conditions are also researched determinants of influenza vaccine uptake. A small number of studies explored the role of social inclusion and system-based interventions.

Discussion and conclusions

This scope review provides a comprehensive overview on factors affecting seasonal influenza vaccination uptake among older citizens. The review also clearly shows gaps for evidence on system-based level or political strategies to improve vaccination uptake.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01793-3.

A cross-sectional study of factors associated with influenza vaccination in Korean cancer survivors

OBJECTIVE

To investigate factors associated with influenza vaccination in cancer survivors.

METHODS

Study subjects were 1,945 Korean adult cancer survivors. Through medical record review and self-administered questionnaires, social and medical information was collected. Influenza vaccination was defined as ever having received a flu vaccine between one year before cancer diagnosis and the survey date. Multiple logistic regression analysis was used to evaluate factors associated with influenza vaccination.

RESULTS

Overall, 60.8% of study subjects had received an influenza vaccination. Younger survivors had a significantly lower vaccination rate than did the elderly survivors (80.22% vs. 54.73%). In younger survivors, longer time elapsed since cancer diagnosis, lifestyle modification counselling during cancer treatment, adequate physical exercise (≥150 min/week) and complementary medication use were positively associated with vaccination, whereas extra-pulmonary cancers, multimodality (≥3) cancer treatment and higher educational achievement were inversely associated. In elderly survivors, fewer factors had a positive (adequate physical exercise) or inverse (multimodality cancer treatment and current smoking) association with influenza vaccination.

CONCLUSION

Influenza vaccination rate was suboptimal, especially among younger cancer survivors. Targeted strategies are necessary to improve influenza vaccination in cancer survivors with consideration of individual characteristics such as age, lifestyle, cancer treatment modality, cancer type and education level.

Machine learning models to identify low adherence to influenza vaccination among Korean adults with cardiovascular disease

Background

Annual influenza vaccination is an important public health measure to prevent influenza infections and is strongly recommended for cardiovascular disease (CVD) patients, especially in the current coronavirus disease 2019 (COVID-19) pandemic. The aim of this study is to develop a machine learning model to identify Korean adult CVD patients with low adherence to influenza vaccination

Methods

Adults with CVD (n = 815) from a nationally representative dataset of the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V) were analyzed. Among these adults, 500 (61.4%) had answered "yes" to whether they had received seasonal influenza vaccinations in the past 12 months. The classification process was performed using the logistic regression (LR), random forest (RF), support vector machine (SVM), and extreme gradient boosting (XGB) machine learning techniques. Because the Ministry of Health and Welfare in Korea offers free influenza immunization for the elderly, separate models were developed for the < 65 and ≥ 65 age groups.

Results

The accuracy of machine learning models using 16 variables as predictors of low influenza vaccination adherence was compared; for the ≥ 65 age group, XGB (84.7%) and RF (84.7%) have the best accuracies, followed by LR (82.7%) and SVM (77.6%). For the < 65 age group, SVM has the best accuracy (68.4%), followed by RF (64.9%), LR (63.2%), and XGB (61.4%).

Conclusions

The machine leaning models show comparable performance in classifying adult CVD patients with low adherence to influenza vaccination.

Factors associated with seasonal influenza immunization in people with chronic diseases

Annually, at a global level, 3 to 5 million people present severe clinical forms of seasonal influenza and up to 650 000 people die of influenza-related complications. People with chronic diseases, such as cardiovascular, pulmonary, renal, hepatic, neurologic, hematologic and metabolic diseases or those reciveing immunosuppressive therapy, constitute a high-risk population group for the development of influenza-related complications, more severe clinical course and poorer health-related outcomes. Due to all of the above, people with chronic diseases are of high priority to receive the influenza vaccine. Immunization represents the key strategy to prevent influenza both in terms of effectiveness and health care costs. Based on the World Health Organization (WHO) recommendations, adequate seasonal influenza immunization coverage among people with chronic diseases is set at 75%. However, few countries achieve this threshold. Understanding predictive factors of vaccination, at different levels of health care delivery (such as individuals, service providers, health policy), is essential to secure acceptance of influenza immunization and achieve the recommended level of vaccination coverage. In this mini review, all the available evidence regarding seasonal influenza vaccination coverage is summarized, alongside factors associated with vaccine uptake in people with chronic diseases as a whole, as well as according to specific diseases such as: cardiovascular and pulmonary disorders, diabetes and cancer. Based on the reviewed empirical evidence, a wide spectrum of factors associated with immunization against influneza was found in people who have chronic diseases. Although diverse, these factors can be systematized into 4 distinctive groups: socio-demographic characteristics, individual attitudes and beliefs, health promoting behaviors and factors related to the health care system. Further efforts are needed to improve the seasonal influenza vaccination coverage. The immunization strategy needs to include the health care system and the community to support people with chronic diseases to continously accept the influenza vaccine.

Care for Breast Cancer Survivors

The number of cancer survivors is increasing globally. More than 15.5 million Americans in 2016 and 1.3 million Koreans in 2013 were living with cancer history. This growing population is expected to increase due to marked development of cancer treatment and early detection. Especially, breast cancer is the second most common cancer in Korean women with relatively favorable 5-year survival rate. Cancer survivors generally face various physical, psychological, and social problems including late-effect or long-term effect after cancer treatment and high risk for second primary cancer and comorbid chronic diseases such as cardiovascular disease and bone health. Breast cancer survivors also encounter wide range of health problems. To satisfy their complex needs, comprehensive supports are required. We categorized the strategy of comprehensive care for breast cancer survivors into (1) Surveillance for primary cancer, (2) Screening of second primary cancer, (3) Management of comorbid health condition, (4) Promoting healthy lifestyle behaviors, and (5) Preventive care. In the future, studies for providing best comprehensive care for breast cancer survivors are needed according to the individuals' demand.

Importance of Awareness and Treatment for Diabetes in Influenza Vaccination Coverage of Diabetic Patients under 65 Years: A Population-Based Study

BACKGROUND

Influenza is a global public health problem causing considerable morbidity and mortality. Although vaccination is the most effective way to prevent infection, vaccination coverage is insufficient in people with chronic disease under 65 years, especially diabetes. The purpose of this study was to evaluate influenza vaccination coverage and identify factors associated with influenza vaccination in Korean diabetic adults under 65 years.

METHODS

Data were obtained from 24,821 subjects in the Korea National Health and Nutrition Examination Survey (2014 to 2017). Socioeconomic, health-related, and diabetic factors were investigated for their relations with influenza vaccination in diabetic patients under 65 years using univariate and multivariate analyses.

RESULTS

Among 24,821 subjects, 1,185 were diabetic patients under 65 years and their influenza vaccination rate was 36.5%. Socioeconomic (older age, female gender, non-smoker, light alcohol drinker, lower educational level, and employed status), health-related factors (lower fasting glucose and glycosylated hemoglobin level, good self-perceived health status, more comorbidities, recent health screening, more outpatient visits, and diet therapy), and diabetic factors (more awareness and getting treated) were associated with influenza vaccination. In multivariate analysis, more awareness and getting treated for diabetes were associated with influenza vaccination in diabetic patients under 65 years (odds ratio, 1.496 and 1.413; 95% confidence interval, 1.022 to 2.188 and 1.018 to 2.054, respectively).

CONCLUSION

Influenza vaccination rate was low in diabetic patients under 65 years, especially in those with unawareness and not getting treated for diabetes. Active screening and treatment for diabetes may be helpful to improve the influenza vaccination rate in these patients.

Seasonal influenza vaccination among cancer patients: A systematic review and meta-analysis of the determinants

Cancer patients are among high-risk individuals for whom seasonal influenza vaccine (SIV) is recommended, but rates of vaccination in this subpopulation remain suboptimal; even in jurisdictions with universal influenza vaccination programs. We sought to summarize the evidence to better understand the determinants of SIV uptake (vaccine receipt) among cancer patients. We searched MEDLINE, Embase, and CINAHL from 2000 to February 12, 2020, focusing on articles on the determinants of seasonal influenza vaccination among cancer patients, published in English. Study selection was conducted independently by 2 reviewers. One reviewer extracted data from the included studies and another reviewer checked the extracted data for errors. Outcomes were sociodemographic and health-related factors. We pooled adjusted results from studies using the inverse variance, random-effects method, and reported the odds ratios (OR) and their 95% confidence intervals (CI). Out of 2664 citations, 10 studies (mostly from USA and South Korea) met our eligibility criteria. Overall, being older (OR 2.23, 95% CI 1.46-3.38; I² 92.3%, [6 studies]), a nonsmoker (1.43, 1.32-1.51; I² 0%, [4 studies]), having a chronic illness (1.18, 1.07-1.29; I² 15.7%, [5 studies]), having had a medical check-up in the past year (1.75, 1.65-1.86; I² 0%, [2 studies]), and having health insurance (1.39, 1.13-1.72; I² 21.8%, [3 studies]) were associated with increased SIV uptake. Compared with being African-American, being Caucasian was also associated with increased SIV uptake (1.79, 1.47-2.13; I² 10.7%, [3 studies]). Limited evidence suggests seasonal influenza vaccination among cancer patients may be determined by some sociodemographic and health-related factors.

Factors associated with pneumococcal vaccination uptake by cancer survivors

PURPOSE

This study aimed to evaluate factors associated with pneumococcal vaccination uptake (PVU) of cancer survivors.

METHODS

A total of 2032 Korean adult cancer survivors diagnosed between June of 1975 and February of 2018 have participated. Information on PVU status and selected variables were collected through self-administered questionnaires and medical record review. Factors associated PVU were investigated using multiple logistic regression analysis.

RESULTS

PVU rate markedly differed by age strata and cancer sites: 73.9% for elderly (≥ 65 years) survivors and 34.6% for younger (< 65 years) survivors and 73.4% for lung cancer survivors and 42.1% for non-lung cancer survivors. Regular physical exercise was associated with higher PVU in both age groups: Odds ratio (OR) and 95% confidence interval (CI) were 1.52 (1.20, 1.94) for younger and 1.78 (1.09, 2.90) for elderly survivors. Complementary medication use was positively associated with PVU with borderline significance in both age groups. However, the association of PVU with other factors differed between the two age groups. In younger survivors, a positive association with PVU was evident for longer time lapse after cancer diagnosis, chronic disease, and living with spouse/or partner, while cancer stage, educational achievement, and alcohol use were inversely associated PVU. On the other hand, multi-modality (≥ 3) cancer treatment was inversely associated with PVU only in elderly survivors.

CONCLUSIONS

PVU of Korean cancer survivors was suboptimal in younger survivors and non-lung cancer survivors. Factors associated with PVU differed between younger and elderly survivors, and more diverse factors were identified for younger survivors.

IMPLICATIONS FOR CANCER SURVIVORS

In order to promote adherence to PVU in cancer survivors, careful consideration of high-risk factors for non-immunization within cancer survivorship context would be necessary together with free-of-charge vaccination policy.

Prevalence and associated factors of influenza vaccination coverage in Korean adults with cardiovascular disease

Infection with influenza virus increases morbidity and mortality in patients with risk factors, including cardiovascular disease (CVD). This study aimed to evaluate factors associated with influenza vaccination coverage in Korean CVD patients.We included 19,599 adults from the 2010 to 2012 Korea National Health and Nutrition Examination Survey. Influenza vaccination rates were compared in subjects with and without CVD. Logistic regression analysis was performed to identify factors associated with influenza vaccination in Korean adults with CVD before and after stratification for age (<65 and ≥65 years).Significantly higher vaccination rates were observed in individuals with CVD than in those without CVD (61.4% vs 31.0%, P < .001). However, young individuals (19-49 years) had decreased influenza vaccination rates, with no difference based on CVD status (20.3% vs 21.6%, P = .859). A lack of private insurance (odds ratio [OR], 0.47; 95% confidence interval [CI], 0.23-0.98) and recent health screening (OR, 4.56; 95% CI, 1.90-10.92) were independent factors for influenza vaccination in CVD patients aged <65 years, whereas female sex (OR, 3.71; 95% CI, 1.24-11.07) and less education (OR, 4.59; 95% CI, 1.27-16.61) were independent factors in CVD patients aged ≥65 years.Improving influenza vaccination coverage for Korean adults with CVD is important, especially in young patients. For young patients with CVD, influenza vaccination status is independently associated with the presence of private insurance and recent health screening. This finding could help establish public health policies to promote influenza vaccination in this population.

Influenza Among Breast Cancer Survivors in South Korea: A Nationwide Population-Based Study

BACKGROUND/AIM

In this study, we analyzed the prevalence of influenza disease in breast cancer survivors using claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea.

PATIENTS AND METHODS

We defined influenza among a nationwide cohort of 87,843 patients who were diagnosed with breast cancer and underwent surgery from January 1, 2010 to December 31, 2014, based on HIRA claim data. Descriptive statistics were calculated to estimate the frequency of influenza disease using diagnostic code and utilization pattern at medical institutions.

RESULTS

Two thousand four hundred breast cancer survivors (2.7%) were diagnosed with influenza. The overall frequency of influenza increased from November (n=98) and peaked in February (n=1,745). Over 60% (2,693) of claims for influenza disease treatment were in the clinic, whereas general hospitals accounted for 22.0% (873). Among 3,967 claims, admission rate was 7.6% (n=301) and the average length of hospitalization was 4.7 days. Elderly breast cancer survivors over 70 years old had the longest length of hospitalization at 5.9 days.

CONCLUSION

Breast cancer survivors are more susceptible to influenza than non-cancer survivors. It is important not only to raise the vaccination rate among young cancer survivors, but also to quickly identify symptoms and begin treatment for flu in elderly cancer survivors.

Influenza Vaccination Coverage Among Polish Patients with Chronic Diseases

Patients at a high-risk of severe influenza, because of their underlying health disorders, are recommended to receive a seasonal influenza vaccination. In Poland, influenza coverage rate in the general population is very low (3.4 %). However, there is little known about the coverage rate among high-risk patients. The aim of this study was to describe a general knowledge, perception, and influenza vaccination coverage rate among Polish patients with enhanced risk for influenza. We conducted a self-reported survey among 500 patients with chronic disorders: 120 pulmonary, 80 hemodialyzed, 100 thyroid cancer, and 200 cardiovascular patients. We found the following influenza vaccination coverage in the respective groups of patients: 58 % in pulmonary, 34 % in hemodialyzed, 32 % in cardiovascular, and 9 % in thyroid cancer patients. The difference between the coverage rate in pulmonary patients compared with the other risk groups was significant (p < 0.05). In pulmonary patients, the most important barrier for influenza vaccination was a lack of recommendations from healthcare workers, while a high awareness of influenza was the most powerful driver for vaccination (p < 0.05). We conclude that although the influenza vaccination coverage in Polish patients with chronic diseases is higher than that reported in the general population, this rate remains much below the recommended level and should be improved.