Health Care for Women International
ISSN: 0739-9332 (Print) 1096-4665 (Online) Journal homepage: http://www.tandfonline.com/loi/uhcw20
Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers HeeJoo Kim, Ji Hye Kim, Yeon Jin Jang & Ji Young Bae To cite this article: HeeJoo Kim, Ji Hye Kim, Yeon Jin Jang & Ji Young Bae (2014): Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers, Health Care for Women International, DOI: 10.1080/07399332.2014.980889 To link to this article: http://dx.doi.org/10.1080/07399332.2014.980889
Accepted author version posted online: 25 Nov 2014. Published online: 26 Jan 2015. Submit your article to this journal
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Date: 06 November 2015, At: 00:29
Health Care for Women International, 00:1–13, 2015 Copyright © Taylor & Francis Group, LLC ISSN: 0739-9332 print / 1096-4665 online DOI: 10.1080/07399332.2014.980889
Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
HEEJOO KIM Department of Social Welfare, Hyupsung University, Gyeonggi-Do, South Korea
JI HYE KIM Faculty of Liberal Arts & Education, Hyupsung University, Gyeonggi-Do, South Korea
YEON JIN JANG Division of Social Welfare, Hanyang Cyber University, Seoul, South Korea
JI YOUNG BAE Department of Social Welfare, Youngdong University, Chungbuk, South Korea
We used the job-demand-control model to answer our two research questions concerning the effects of working conditions on self-rated health and gender differences and the association between these working conditions and health among Korean manual workers. Since a disproportionate representation of women in nonstandard work positions is found in many countries, including Korea, it is important to examine how working conditions explain gender inequality in health. We used data from the 2008–2009 Korean National Health and Nutrition Examination Survey and analyzed a total sample of 1,482 men and 1,350 women using logistic regression. We found that job control was positively related to self-rated health, while both physical and mental job demands were negatively related to self-rated health. We also found significant interaction effects of job demands, control, and gender on health. Particularly, female workers’ health was more vulnerable to mentally
Received 19 April 2013; accepted 6 October 2014. Address correspondence to Ji Hye Kim, Faculty of Liberal Arts & Education, Hyupsung University, 72 Choerubaeck-ro, Bongdam-eup, Hwaseong-Si, Gyeonggi-Do 445-745, South Korea. E-mail: [email protected] 1
2
H. Kim et al.
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
demanding job conditions. We discussed theoretical and practice implications based on these findings. Over the past 30 years, both developing and developed countries in response to the growing demands for neoliberal economic restructuring and labor market flexibility have created various types of “atypical” or “nonstandard” work (Casey & Alach, 2004; Kim, Khang, Muntaner, Chun, & Cho, 2008). These new forms of nonstandard jobs include complex characteristics of precarious employment such as insecurity, low wages, and lack of benefits as well as the temporary and part-time employment status (Menendez, Benach, Muntaner, Amable, & O’Campo, 2007). Public and occupational health scholars have reported that nonstandard employment and its associated working conditions adversely affected workers’ health (i.e., poor physical and mental functioning and depression; Bauer, Huber, Jenny, M¨uller, & H¨ammig, 2009; Sekine, Chandola, Martikainen, Marmot, & Kagamimori, 2009). Moreover, occupational inequality in health is strongly related with gender differences. Due to the strong gender segregation in the labor markets, women are disproportionately represented in nonstandard work positions (De Ruyter & Warnecke, 2008; Young, 2010), and are more likely to experience poorer health than men in many countries (Kim, Khang, Cho, Chun, & Muntaner, 2011; O’Campo et al., 2004). Despite the international interest in gender inequalities and health-related consequences, few studies have been carried out to understand the underlying mechanisms of gender inequalities in occupational health outcomes. In the current study, using the Job-Demand-Control (JDC) Model as a theoretical framework, we attempted to identify whether gender differences exist in working conditions and their relationships with health outcomes. The JDC model is a widely cited model for explaining the relationship between employees’ psychosocial working conditions and health (De Jonge, Dollard, Dormann, LeBlanc, & Houtman, 2000; Laaksonen, Rahkonen, Martikainen, & Lehelma, 2006; Huang, Du, Chen, Yang, & Huang, 2011). Karasek (1979) postulates two dimensions of work environment: job demands and job control. Job demands refer to the time pressure brought on by heavy workloads, fast-paced work environment, and role conflict. Job control is conceptualized as the worker’s authority to make his or her own decisions and the variety of skills the worker uses on the job (De Bruin & Taylor, 2006). According to the strain hypothesis of this model, employees experiencing high psychological demands and low control at work are more likely to have psychosocial and physical impairment and mental disorders (Dalgard, Sorensen, Sandanger, Nygard, Svensson, & Reas, 2009; Huang et al., 2011; Laaksonen et al., 2006). More specifically, this model is useful to explain why women in lower occupational positions are exposed to more stressful and poorer working conditions and consequently report more health problems than men (Karasek & Theorell, 1990; Kaikkonen, Rahkonen, Lallukka, & Lahelma,
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Health of Korean Manual Workers
3
2009). The extent, however, of gender disparity in health resulting from employment status and its associated working conditions may vary by country. We set out, therefore, to test the measures of the JDC model and their gender-dependent effects on health. Because of occupational gender segregation and discrimination in the South Korean labor market, women are more likely than men to be employed in nonstandard work (Kim et al., 2008). In addition, women who leave the labor force during the childrearing years have difficulty in reentering the labor market in South Korea. As a result, they experience career interruptions and job-related barriers (Lee, 2003). This is also why a large proportion of female workers are engaged in the “5Cs” (cleaning, cashiering, catering, caring, and clerical work) and service work (sales; Choi, 2009). These jobs are generally known to be insecure, exhausting, and low paid, and the working conditions inherent to them often worsen workers’ health (Son, 2009). In a sample of 3,280 Korean employees aged 20–64 years, 35.2% of female employees compared with 18.8% of male employees were nonstandard workers and reported poor mental health (Kim, Muntaner, Khang, Paek, & Cho, 2006). In response to this rapidly changing working environment and its significant effects on workers’ health, we aimed to examine the relationships between employees’ working conditions and self-rated health among South Korean manual workers, using the JDC model. We also sought to identify gender differences in the associations between the aspects of the JDC model and self-rated health. Self-rated health is a commonly used measure of health status reflecting physical, and personal components (Laaksonen et al., 2006). In addition, homogeneous samples would provide more individual and within-occupation variations in working conditions for testing the JDC model (De Lange, Taris, Kompier, Houtman, & Bonger, 2003). Thus, we focused on manual workers, such as service and sales workers, machine operators, and unskilled labor, who are regarded as a high-risk group for severe work-related stress and poorer self-rated health (Karasek & Theorell, 1990; Kaikkonen et al., 2009; Lahelma, Laaksonen, & Aittomaki, 2009). The specific research questions are as follows: (a) How do job demands and control influence the health of Korean manual workers? (b) Do the effects of job demands and control on health vary by gender?
METHODS Data and Population We used data from the 2008–2009 Korean National Health and Nutrition Examination Survey (KNHANES IV) conducted by the Korea Centers for Disease Control and Prevention. The KNHANES IV was a nationwide survey
4
H. Kim et al.
that used a stratified multistage probability sampling design. Furthermore, this survey was one of the first studies in South Korea to collect information about the working conditions of Korean employees. From the survey results, we selected variables such as age, gender, education, employment status, occupation, marital status, household income, health-related behaviors, and working condition. We selected data only from employees in manual occupations. A total sample of 2,832 was obtained from the KNHANES IV (1,482 men and 1,350 women).
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Measures Self-rated health. Poor self-rated health was assessed by a question: “How would you rate your health as compared to others of your age?” Responses were made on 5-point Likert scale ranging from “very good” to “very poor.” We combined “poor” or “very poor” to form a category called “poor self-rated health.” We focused on employees’ poor health because it is often associated with living in poverty, and helping people escape poverty is major concern of health services. Gender. Gender was used as an independent variable to investigate the main effect and the interaction effects with job control and demands on health status of Korean manual workers. Gender was coded 0 for men and 1 for women. Job demands and job control. We focused more specific aspects of job demands in our study, and we used separate measures of mental and physical job demands. Three independent variables of job demands and control, therefore, were measured: mental demands, physical demands, and job control. Mental demands were assessed by two items referring to the mentally demanding aspects of the work, such as working under time pressure and hiding one’s emotions. An example item was “I always have to work under time pressure due to heavy work load.” Physical demands were also measured by two items associated with physical workload and carrying heavy loads. The items were as follows: “I have to work in uncomfortable positions for a long time,” and “My job requires me to lift and carry heavy loads.” For the job control variable, we used two items referring to the decision authority. An example statement was “I have the authority to make decisions on my own.” To measure job control and demands, we used a 4-point scale ranging from 1 (never) to 4 (always). Physical and mental demands and job control scores were calculated by summing the individual item scores. In relation to the interactive effects of gender and JDC, interaction terms for gender and JDC were added. To reduce the effect of multicollinearity, we conducted mean centering of the independent variables of job control and physical and mental job demands.
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Health of Korean Manual Workers
5
Control variables. We used socioeconomic variables, including age, education level, employment status, marital status, and household income, and a work-related variable (working overtime). Education level was categorized into three groups: middle school or less, high school, and college/university or higher. We defined middle school or less as “low educated.” Employment status was divided into standard versus nonstandard. Standard workers were defined as full-time, permanent workers, while nonstandard workers were defined as part-time, temporary, or daily workers. Marital status was dichotomized as living with (married) or without (unmarried, widowed, or divorced) a spouse. To assess household income, we used the log of equivalized household income after adjusting for the number of household members. To assess working overtime, respondents were asked if they worked more than 40 hours per week. We also used health behaviors, including smoking, drinking alcohol, and exercising. Drinking behavior was measured using an item assessing average monthly alcohol consumption during the year prior to the survey. Respondents were also asked whether they had smoked more than 100 cigarettes in their life and were still smoking. Regular exercise was assessed with a question on whether participants exercised regularly for at least 30 minutes at a time, five times a week.
Data Analysis Gender differences in sociodemographic characteristics, job control and demands, and poor self-rated health were tested with chi-square tests and t tests. A hierarchical logistic regression analysis was applied to test both the main effects of job control and demands (physical and mental) and the interaction effects of gender and working conditions on self-rated poor health. First, the base model included all control variables including age, education, employment status, marital status, household income, working hours, and health-related behaviors (Model 1). Second, the main independent variables including gender and job control and physical and mental job demands were added (Model 2 and 3). Third, the interaction terms between job control, job demands (physical and mental), and gender were added (Model 4). All analyses were conducted using SPSS 18.0. Sample weights were used for all analyses to derive unbiased estimates of the population (Kim et al., 2008).
RESULTS Descriptive Data In Table 1, we show the sociodemographic characteristics of the respondents. Of 2,832 respondents in this study, 1,350 were women and 1,482 were men. The largest group of female workers was 45–54 years of age while that
6
H. Kim et al.
TABLE 1 Sociodemographic Characteristics of Manual Workers Male N (%) Female N (%) 1,482 1,350
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Characteristic Age
ISSN: 0739-9332 (Print) 1096-4665 (Online) Journal homepage: http://www.tandfonline.com/loi/uhcw20
Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers HeeJoo Kim, Ji Hye Kim, Yeon Jin Jang & Ji Young Bae To cite this article: HeeJoo Kim, Ji Hye Kim, Yeon Jin Jang & Ji Young Bae (2014): Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers, Health Care for Women International, DOI: 10.1080/07399332.2014.980889 To link to this article: http://dx.doi.org/10.1080/07399332.2014.980889
Accepted author version posted online: 25 Nov 2014. Published online: 26 Jan 2015. Submit your article to this journal
Article views: 49
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=uhcw20 Download by: [University of Lethbridge]
Date: 06 November 2015, At: 00:29
Health Care for Women International, 00:1–13, 2015 Copyright © Taylor & Francis Group, LLC ISSN: 0739-9332 print / 1096-4665 online DOI: 10.1080/07399332.2014.980889
Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
HEEJOO KIM Department of Social Welfare, Hyupsung University, Gyeonggi-Do, South Korea
JI HYE KIM Faculty of Liberal Arts & Education, Hyupsung University, Gyeonggi-Do, South Korea
YEON JIN JANG Division of Social Welfare, Hanyang Cyber University, Seoul, South Korea
JI YOUNG BAE Department of Social Welfare, Youngdong University, Chungbuk, South Korea
We used the job-demand-control model to answer our two research questions concerning the effects of working conditions on self-rated health and gender differences and the association between these working conditions and health among Korean manual workers. Since a disproportionate representation of women in nonstandard work positions is found in many countries, including Korea, it is important to examine how working conditions explain gender inequality in health. We used data from the 2008–2009 Korean National Health and Nutrition Examination Survey and analyzed a total sample of 1,482 men and 1,350 women using logistic regression. We found that job control was positively related to self-rated health, while both physical and mental job demands were negatively related to self-rated health. We also found significant interaction effects of job demands, control, and gender on health. Particularly, female workers’ health was more vulnerable to mentally
Received 19 April 2013; accepted 6 October 2014. Address correspondence to Ji Hye Kim, Faculty of Liberal Arts & Education, Hyupsung University, 72 Choerubaeck-ro, Bongdam-eup, Hwaseong-Si, Gyeonggi-Do 445-745, South Korea. E-mail: [email protected] 1
2
H. Kim et al.
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
demanding job conditions. We discussed theoretical and practice implications based on these findings. Over the past 30 years, both developing and developed countries in response to the growing demands for neoliberal economic restructuring and labor market flexibility have created various types of “atypical” or “nonstandard” work (Casey & Alach, 2004; Kim, Khang, Muntaner, Chun, & Cho, 2008). These new forms of nonstandard jobs include complex characteristics of precarious employment such as insecurity, low wages, and lack of benefits as well as the temporary and part-time employment status (Menendez, Benach, Muntaner, Amable, & O’Campo, 2007). Public and occupational health scholars have reported that nonstandard employment and its associated working conditions adversely affected workers’ health (i.e., poor physical and mental functioning and depression; Bauer, Huber, Jenny, M¨uller, & H¨ammig, 2009; Sekine, Chandola, Martikainen, Marmot, & Kagamimori, 2009). Moreover, occupational inequality in health is strongly related with gender differences. Due to the strong gender segregation in the labor markets, women are disproportionately represented in nonstandard work positions (De Ruyter & Warnecke, 2008; Young, 2010), and are more likely to experience poorer health than men in many countries (Kim, Khang, Cho, Chun, & Muntaner, 2011; O’Campo et al., 2004). Despite the international interest in gender inequalities and health-related consequences, few studies have been carried out to understand the underlying mechanisms of gender inequalities in occupational health outcomes. In the current study, using the Job-Demand-Control (JDC) Model as a theoretical framework, we attempted to identify whether gender differences exist in working conditions and their relationships with health outcomes. The JDC model is a widely cited model for explaining the relationship between employees’ psychosocial working conditions and health (De Jonge, Dollard, Dormann, LeBlanc, & Houtman, 2000; Laaksonen, Rahkonen, Martikainen, & Lehelma, 2006; Huang, Du, Chen, Yang, & Huang, 2011). Karasek (1979) postulates two dimensions of work environment: job demands and job control. Job demands refer to the time pressure brought on by heavy workloads, fast-paced work environment, and role conflict. Job control is conceptualized as the worker’s authority to make his or her own decisions and the variety of skills the worker uses on the job (De Bruin & Taylor, 2006). According to the strain hypothesis of this model, employees experiencing high psychological demands and low control at work are more likely to have psychosocial and physical impairment and mental disorders (Dalgard, Sorensen, Sandanger, Nygard, Svensson, & Reas, 2009; Huang et al., 2011; Laaksonen et al., 2006). More specifically, this model is useful to explain why women in lower occupational positions are exposed to more stressful and poorer working conditions and consequently report more health problems than men (Karasek & Theorell, 1990; Kaikkonen, Rahkonen, Lallukka, & Lahelma,
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Health of Korean Manual Workers
3
2009). The extent, however, of gender disparity in health resulting from employment status and its associated working conditions may vary by country. We set out, therefore, to test the measures of the JDC model and their gender-dependent effects on health. Because of occupational gender segregation and discrimination in the South Korean labor market, women are more likely than men to be employed in nonstandard work (Kim et al., 2008). In addition, women who leave the labor force during the childrearing years have difficulty in reentering the labor market in South Korea. As a result, they experience career interruptions and job-related barriers (Lee, 2003). This is also why a large proportion of female workers are engaged in the “5Cs” (cleaning, cashiering, catering, caring, and clerical work) and service work (sales; Choi, 2009). These jobs are generally known to be insecure, exhausting, and low paid, and the working conditions inherent to them often worsen workers’ health (Son, 2009). In a sample of 3,280 Korean employees aged 20–64 years, 35.2% of female employees compared with 18.8% of male employees were nonstandard workers and reported poor mental health (Kim, Muntaner, Khang, Paek, & Cho, 2006). In response to this rapidly changing working environment and its significant effects on workers’ health, we aimed to examine the relationships between employees’ working conditions and self-rated health among South Korean manual workers, using the JDC model. We also sought to identify gender differences in the associations between the aspects of the JDC model and self-rated health. Self-rated health is a commonly used measure of health status reflecting physical, and personal components (Laaksonen et al., 2006). In addition, homogeneous samples would provide more individual and within-occupation variations in working conditions for testing the JDC model (De Lange, Taris, Kompier, Houtman, & Bonger, 2003). Thus, we focused on manual workers, such as service and sales workers, machine operators, and unskilled labor, who are regarded as a high-risk group for severe work-related stress and poorer self-rated health (Karasek & Theorell, 1990; Kaikkonen et al., 2009; Lahelma, Laaksonen, & Aittomaki, 2009). The specific research questions are as follows: (a) How do job demands and control influence the health of Korean manual workers? (b) Do the effects of job demands and control on health vary by gender?
METHODS Data and Population We used data from the 2008–2009 Korean National Health and Nutrition Examination Survey (KNHANES IV) conducted by the Korea Centers for Disease Control and Prevention. The KNHANES IV was a nationwide survey
4
H. Kim et al.
that used a stratified multistage probability sampling design. Furthermore, this survey was one of the first studies in South Korea to collect information about the working conditions of Korean employees. From the survey results, we selected variables such as age, gender, education, employment status, occupation, marital status, household income, health-related behaviors, and working condition. We selected data only from employees in manual occupations. A total sample of 2,832 was obtained from the KNHANES IV (1,482 men and 1,350 women).
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Measures Self-rated health. Poor self-rated health was assessed by a question: “How would you rate your health as compared to others of your age?” Responses were made on 5-point Likert scale ranging from “very good” to “very poor.” We combined “poor” or “very poor” to form a category called “poor self-rated health.” We focused on employees’ poor health because it is often associated with living in poverty, and helping people escape poverty is major concern of health services. Gender. Gender was used as an independent variable to investigate the main effect and the interaction effects with job control and demands on health status of Korean manual workers. Gender was coded 0 for men and 1 for women. Job demands and job control. We focused more specific aspects of job demands in our study, and we used separate measures of mental and physical job demands. Three independent variables of job demands and control, therefore, were measured: mental demands, physical demands, and job control. Mental demands were assessed by two items referring to the mentally demanding aspects of the work, such as working under time pressure and hiding one’s emotions. An example item was “I always have to work under time pressure due to heavy work load.” Physical demands were also measured by two items associated with physical workload and carrying heavy loads. The items were as follows: “I have to work in uncomfortable positions for a long time,” and “My job requires me to lift and carry heavy loads.” For the job control variable, we used two items referring to the decision authority. An example statement was “I have the authority to make decisions on my own.” To measure job control and demands, we used a 4-point scale ranging from 1 (never) to 4 (always). Physical and mental demands and job control scores were calculated by summing the individual item scores. In relation to the interactive effects of gender and JDC, interaction terms for gender and JDC were added. To reduce the effect of multicollinearity, we conducted mean centering of the independent variables of job control and physical and mental job demands.
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Health of Korean Manual Workers
5
Control variables. We used socioeconomic variables, including age, education level, employment status, marital status, and household income, and a work-related variable (working overtime). Education level was categorized into three groups: middle school or less, high school, and college/university or higher. We defined middle school or less as “low educated.” Employment status was divided into standard versus nonstandard. Standard workers were defined as full-time, permanent workers, while nonstandard workers were defined as part-time, temporary, or daily workers. Marital status was dichotomized as living with (married) or without (unmarried, widowed, or divorced) a spouse. To assess household income, we used the log of equivalized household income after adjusting for the number of household members. To assess working overtime, respondents were asked if they worked more than 40 hours per week. We also used health behaviors, including smoking, drinking alcohol, and exercising. Drinking behavior was measured using an item assessing average monthly alcohol consumption during the year prior to the survey. Respondents were also asked whether they had smoked more than 100 cigarettes in their life and were still smoking. Regular exercise was assessed with a question on whether participants exercised regularly for at least 30 minutes at a time, five times a week.
Data Analysis Gender differences in sociodemographic characteristics, job control and demands, and poor self-rated health were tested with chi-square tests and t tests. A hierarchical logistic regression analysis was applied to test both the main effects of job control and demands (physical and mental) and the interaction effects of gender and working conditions on self-rated poor health. First, the base model included all control variables including age, education, employment status, marital status, household income, working hours, and health-related behaviors (Model 1). Second, the main independent variables including gender and job control and physical and mental job demands were added (Model 2 and 3). Third, the interaction terms between job control, job demands (physical and mental), and gender were added (Model 4). All analyses were conducted using SPSS 18.0. Sample weights were used for all analyses to derive unbiased estimates of the population (Kim et al., 2008).
RESULTS Descriptive Data In Table 1, we show the sociodemographic characteristics of the respondents. Of 2,832 respondents in this study, 1,350 were women and 1,482 were men. The largest group of female workers was 45–54 years of age while that
6
H. Kim et al.
TABLE 1 Sociodemographic Characteristics of Manual Workers Male N (%) Female N (%) 1,482 1,350
Downloaded by [University of Lethbridge] at 00:30 06 November 2015
Characteristic Age
