This study aimed to investigate the association between living arrangements and influenza vaccination among elderly South Korean subjects.
We used data from the fifth Korean National Health and Nutrition Examination Survey. Participants older than 65 years were included and categorized into 4 groups according to the type of living arrangement as follows: (1) living alone group; (2) living with a spouse group; (3) living with offspring (without spouse) group; and (4) living with other family members group. A total of 1,435 participants were included in this cross-sectional analysis.
A lower vaccination rate was observed in the living with offspring (without spouse) group, whereas the living with a spouse group had higher rates of both seasonal and H1N1 influenza vaccination. After adjusting for age, sex, region, education level, income level, and number of comorbidities, the living with offspring (without spouse) group had a higher H1N1 vaccination non-receipt rate than the living alone group (odds ratio, 2.03; 95% confidence interval, 1.08-3.82).
Influenza vaccination rates differed according to the type of living arrangement. Particularly, those living with offspring (without spouse) had the lowest H1N1 influenza vaccination rate compared to those with other living arrangements, and this difference was significant. Interventions to improve influenza vaccination coverage should target not only elderly persons who live alone, but also those living with offspring.
Influenza is a worldwide public health problem.
Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses.
Data for this cross-sectional study were obtained from the second year (2011) of the fifth Korean National Health and Nutrition Examination Survey (KNHANES V-2), which was conducted by the Korean Centers for Disease Control and Prevention to assess the health and nutritional status of the South Korean population. KNHANES V-2 comprised a health examination survey; a comprehensive self-reported questionnaire of anthropometric and demographic characteristics, socioeconomic status, and comorbidities; and a nutrition survey. A geographic region based-multistage probability sampling, stratified according to sex and age, was used to select household units. A total of 8,518 individuals from these sampling frames were included in the 2011 survey. Among them, 1,598 individuals aged over 65 years were identified as possible participants in our study. We excluded those with missing data regarding living arrangements and influenza vaccine receipt. We also excluded participants for whom information on confounding variables (region, household income, education level, and chronic diseases) was missing. A total of 1,435 participants were ultimately eligible for this study. All study participants provided written informed consents. The study was approved by the institutional review board (IRB) of Korea Centers for Disease Control and Prevention (IRB: 2011-02CON-06-C).
Sixteen regions (Seoul, 6 metropolitan cities, and 9 provinces) were defined for KNHANES. In this study, the regions were recategorized into 3 groups (Seoul, metropolitan cities, and provinces). Household income levels were divided into quartiles, which were calculated based on equalized income (total household income divided by the square root of the number of people in a household). Education level was classified into 4 categories: completion of elementary school, middle school, high school, and post-secondary school. In this study, chronic diseases included hypertension, hyperlipidemia, stroke, angina, myocardial infarction, pulmonary tuberculosis, asthma, diabetes, and cancer. Seasonal influenza and H1N1 influenza vaccine receipt were self-reported separately as a yes response to a question on whether the participant had received the vaccination during the past year. Types of living arrangements were grouped into 4 categories according to the response to "what is your type of household?" These groups were living alone (answered "single person household"), living with a spouse (answered "living with a spouse only or a spouse and other family members, including offspring, parents, or others"), living with offspring (without a spouse; answered "living as a single parent without a spouse), and living with other family members (all others).
Statistical analyses were conducted using SPSS statistical software ver. 12.0 (SPSS Inc., Chicago, IL, USA). One-way analysis of variance was used to compare the means of continuous variables among living arrangement groups. Categorical variables were assessed using the chi-square test. Logistic regression analyses were used to examine the association between living arrangements and influenza vaccination. All tests were two-sided, and a P-value<0.05 was considered statistically significant.
The participants' ages ranged from 65 to 97 years, with a mean age of 72.8 years, and 57.6% (n=827) of the participants were women.
Previous studies have investigated factors associated with influenza vaccination, such as age, sex, educational level, household income, place of residence, contact with the health care system, hospitalization, and comorbidities. We further examined the associations between the type of living arrangements and seasonal and H1N1 influenza vaccination rates among elderly South Korean individuals. This study showed that compared with the living alone group, those living with offspring (without spouse) were less likely to receive influenza vaccinations. In particular, those living with offspring (without spouse) had a statistically significantly lower rate of H1N1 influenza vaccination, even after adjusting for confounding variables. Furthermore, although these results were not statistically significant, those living with a spouse were more likely to have received influenza vaccinations than subjects in the other living arrangement groups. Our findings are similar to those of several previous studies. A previous study reported that compared with the living alone group, subjects in the living with adult offspring group were less likely to receive recommended preventive care such as influenza vaccinations and physical and dental checkups, whereas subjects in the living with a spouse only group were more likely to receive preventive care.
Social network channels, which represent the web of social relationships with family members, close friends, and more formal relationships, are a good resource of health information and health practices. Elderly individuals who live with their offspring tend to have narrow social network channels that focus only on their offspring.
This study has the following limitations. First, the survey asked whether participants had received the vaccination during the past year and thus could not reflect more current changes in living arrangements. Second, influenza vaccination receipt data were self-reported and thus subject to recall bias. Furthermore, a trivalent influenza vaccine that provides simultaneous protection against 3 strains at once (influenza, A/H3N2, A/H1N1, and influenza B) was first offered in 2010,
In conclusion, our findings suggest differences in the influenza vaccination rates according to the type of living arrangements. In particular, those living with offspring (without spouse) had a significantly lower H1N1 influenza vaccination rate when compared to subjects with other living arrangements. Interventions to improve influenza vaccination coverage should target not only elderly persons who live alone, but also those living with offspring.
Values are presented as numbers (%) or means±SD.
*Analysis of variance and the chi-square test were used for the statistical analysis of continuous and categorical variables, respectively. †Education levels were classified into 4 categories: completion of elementary school, middle school, high school, and post-secondary school. ‡Household income levels were divided into quartiles calculated according to equalized income (total household income divided by the square root of the number of people in a household).
*Logistic regression analyses were used for the statistical analysis. †Adjusted for age, sex, region, education level, income level, and number of comorbidities.
*Logistic regression analyses were used for the statistical analysis. †Adjusted for age, sex, region, education level, income level, and number of comorbidities.