Let's get started by reviewing some of the ways in which working conditions may affect our health. After watching this video, you'll be able to identify some examples of health damaging and health promoting aspects of work, explain how psychological demands and decision latitude interact in the workplace to affect health, and discuss how an imbalance between effort and rewards at work may negatively impact health. In the first column, I've listed some of the health damaging aspects of work. These include physical demands like heavy lifting or prolonged sitting or standing, exposure to environmental hazards like radiation or loud noises, psychological demands from the boss or from customers and control over work tasks, effort-reward imbalance, work-family conflict, and nonstandard work schedules like working the night shift. The second column lists some potential health-promoting aspects of work, which have received less attention from social epidemiologists. These include social engagement and social support, role enhancement, and productivity and meaning. In this column, we could also add income and other material benefits that come from employment, like health insurance. In this lecture, we're going to focus on two models that had been developed to understand the effects of job strain on the health of workers. The first model is called the demand-control model or Karasek's job stream model. This is a two-dimensional model that focuses on the intersection of decision latitude and psychological demands. Decision latitude is related to Marx's concept of alienated labor. It involves an employee's control over the use of her skills, also known as skill utilization, and the amount of control or authority that she has over decisions that are relevant to her work tasks. As an example, think about two cooks; one is the head chef at her own restaurant, and the other is a line cook who works for the head chef. The head chef has high decision latitude because she gets to decide what goes on the menu, how it should be prepared, and how much she's going to charge customers to order it. The line cook may have skills that are comparable to those of the head chef, but she doesn't get to decide what to cook or how to cook it. She has to follow the head chef's instructions, so she has relatively low decision latitude. The other part of Karasek's model focuses on psychological demands. This refers to qualitative emotional demands like dealing with an upset customer or patient, and quantitative demands like the number of performances per unit of time. Going back to our example of the two cooks, the psychological demands are likely to be different. The head chef may be responsible for figuring out what the demand will be for a particular entree, so she doesn't order too much or too little of an ingredient, and she's probably the one who has to deal with unhappy customers or employees. The line chef on the other hand, has to work at a pace that matches customer demand. If it's a busy night, she may have to work twice as quickly as usual to make sure everyone gets their food on time. When you combine these two dimensions of work, decision latitude and psychological demands, you get a two-by-two table like the one you see here. This produces four types of jobs. The first is active jobs, which are characterized by high psychological demands and a high level of control. The head chef probably falls into this category, and other examples include physicians and engineers. The opposite of active jobs are passive jobs, which have low demands combined with low control. Examples of this type of job include a night guard or a toll booth operator. The third type of job is described as low strain. Low strain jobs are characterized by low demands and high control. Examples might include artists and writers. The last type of job is the high strain job, which combines high demands and low control. The line cook from our previous example might fall into this category, as would assembly line workers, nurses aides, and call center operators. Karasek hypothesized that low strain jobs would be best for health, while high strain jobs would be most toxic. He argued that what matters for health is the balance between demands and control, not just the amount of demands a person faces at work. A few different scales have been developed to measure job strain. The original scale included seven questions about job demands and eight questions about job decision latitude. Newer versions also include questions about social support at work, physical demands, and job insecurity, and can include up to 49 questions. Many studies have examined job strain as a predictor of health outcomes. The evidence suggests that job strain is associated with increased coronary heart disease, hypertension, and mental disorder, but not cancer. Evidence for health behaviors is mixed, and overall, the effects of job strain appear to be small compared to other risk factors like smoking. Another model that's been proposed to examine the effects of working conditions on health is the effort-reward imbalance model. According to this model, the health consequences of work depends on the degree to which workers are rewarded for their efforts. When a high degree of effort doesn't produce a high degree of reward, then the risk of illness goes up. In this model, effort refers to the individual's response to demands, which may be extrinsic, meaning they come from someone else like a boss or a customer, or intrinsic, meaning they come from the employee herself. Rewards refer to financial compensation like increased pay, and non-financial benefits like self-esteem and social control. A healthy state is achieved when there is a balance between efforts and rewards. Effort-reward imbalance is measured in surveys by asking questions about intrinsic effort, extrinsic effort, and occupational rewards, and responses are combined into a scale. Effort-reward imbalance has been associated with cardiovascular outcomes in a number of studies, and there's some evidence that the decision latitude component of the demand-control model and the effort reward imbalance model contribute independently to new coronary heart disease events. This suggests that control and reward are separate dimensions of work that affect health. In the next video, we're going to talk about work-family conflict, nonstandard work schedules, and the future of work.
