Thursday October 15 2009
Working after retirement has health benefits
“Work is good for you, especially after you've retired,” says the Daily Mail. The newspaper and others report that workers who stop working suddenly the moment they reach retirement age are at greater risk of heart attacks, cancer and other major diseases than those who ease their way into old age by taking a part-time job.
Part-time work in jobs related to previous careers was also better for mental health than “full” retirement.
This six-year study looked at data from more than 12,000 people of retirement age. The researchers looked at the rates at which they developed medical problems including high blood pressure, diabetes, cancer, lung disease, heart disease, strokes and mental problems. They tried to take into account the fact that people may have had these problems before the study started, to ensure that bad health causing early retirement could not be blamed for the effect.
Overall, this study suggests some health benefits for people who keep working beyond the age of 58, and although not altogether surprising this will add to the debate about the “ideal” age to stop working. More research is needed into how such work helps different groups of people.
Where did the story come from?
The research was carried out by Yujie Zhan and colleagues from the University of Maryland and California State University. Collection of data for the study was funded by the National Institute on Aging in the US. It was published in the peer-reviewed Journal of Occupational Health Psychology.
What kind of scientific study was this?
This study investigated the effect on health of so-called “bridge employment”, which is part-time employment, self-employment, or temporary employment after full-time employment ends and before permanent retirement begins.
The data for this study came from a cohort study called the Health Retirement Study, which collected data in 1992, 1994, 1996 and 1998.
The data included in this study was from 12,189 retired volunteers who had been interviewed for one to two hours about their age, sex and other demographic information, health, wealth, employment history and current work or retirement life.
The researchers combined and examined data for people whose employment status had been recorded in 1992 and health and retirement status recorded in 1996, and people whose employment status was recorded in 1994 and health status recorded in 1998.
Only people who were not retired at the first assessment were included, and the researchers looked at how their employment/retirement changed in subsequent surveys. They categorised those who were partly employed between these dates into two main types: career bridge employment (individuals who accept bridge employment in the same occupation as their career jobs) and bridge employment in a different field.
The diagnoses for eight specific diseases had to have been made by a doctor. These were:
- high blood pressure,
- lung disease,
- heart disease,
- psychiatric problems, and
These were then coded as either being present or not. A technique called multiple regression, a type of modelling, was used to test the link between these and employment status. Other factors such as age, gender, education level and total wealth were also taken into account.
What were the results of the study?
The average age of the participants whose data was collected in 1992 was 54, and in 1994 it was 55. This meant the average age at the second data collection points were 58 in 1996 and 59 in 1998.
Retirees who continued to work in a bridge job experienced fewer major diseases than those who were fully retired. These effects occurred whether the participants worked in their career field or a different one. Complete retirees also had more major diseases when compared with those who did not retire at all.
Compared to full retirement, bridge employment was also related to improved mental health, but only when the bridge employment was within the person's career field.
What interpretations did the researchers draw from these results?
The researchers say that their findings highlight the “health benefits of engaging in bridge employment for retirees.”
They note that these significant predictive effects were still present after taking into account the health of individuals before retirement. They say this implies that there was a clear direction of influence in which employment status was causing the differences in health, rather than the other way around.
They discuss practical implications of their study, and suggest that individuals should carefully consider whether to engage in bridge employment. If they do choose to carry on working, the researchers say that the types of bridge employment a person chooses is "quite important".
They also suggest that governments and corporate policy makers should promote these beneficial effects of bridge employment.
What does the NHS Knowledge Service make of this study?
This cohort study collected a large amount of data at several points in time, allowing the researchers to compare factors recorded before the health outcomes (before the participants developed a condition). This is not possible in other studies, for example in cross-sectional studies that collect all data at one point. Four limitations are mentioned by the researchers:
- Despite the attempts made to ensure that the health outcomes were measured after the first data collection, it is possible that reverse causation is occurring. This means that the health conditions may not just be the result of bridge employment, but also might have affected the decision to take on bridge employment or retire completely. The design tried to overcome this but may have failed to eliminate this bias completely.
- The single measure used for each kind of health outcome (either being present or not) might have oversimplified the complexity of health problems, particularly the varying severity of some conditions that occur in older people. In addition, as these outcomes were reported by the participants themselves, some diseases may have been missed or misclassified.
- How bridge employment might be of benefit to health is not addressed by the study. It is possible, for example, that the social ties and social support provided by bridge employment could be the important feature, in which case it would not just be the work but the social contact provided by enjoyable work that was helpful.
- The data for this study was collected 10 years ago and may not apply to the current workforce, or to workforces in non-US countries.
Despite these issues, the findings of this study follow common sense, which suggests that maintaining meaningful activity beyond the age of 58 is good for physical and mental health.