Live Well to Live Long

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Prediction of mortality in type 2 diabetes from health-related quality of life (ZODIAC-4), by Nanne Kleefstra and colleagues. Diabetes Care 31:932--933, 200

What is the problem and what is known about it so far?

Health-related quality of life (HRQOL) refers to what people think about their physical and mental health. Measuring the HRQOL of someone with a chronic illness like diabetes can shed light on how the illness interferes with the person's day-to-day life and well-being. Previous studies have shown that worse HRQOL is related to higher death risk in people without diabetes. Whether this holds true in people with type 2 diabetes has not been previously studied.

Why did researchers do this particular study?

The researchers wanted to learn more about the relationship between HRQOL and the risk of death in people with type 2 diabetes.

Who was studied?

Subjects included 1,143 primary care patients with type 2 diabetes who had taken part in a previous study in 1998.

How was the study done?

Researchers looked at data collected on the subjects at the start of the 1998 study, including their medical history, diabetes control, lab results, and scores on a questionnaire measuring their HRQOL. They then determined how many of these patients had died by 2004 and analyzed this information to see whether HRQOL was related to death.

What did the researchers find?

Worse HRQOL scores were related to higher death risks. Patients with low scores in 1998 were more than twice as likely to die during the ensuing 6 years as those with high scores.

What were the limitations of the study?

Of the subjects in the study, one-fourth did not fill in or complete their HRQOL questionnaire in 1998. However, not completing the questionnaire itself was strongly related to higher death risks, so this probably led researchers to underestimate, rather than overestimate, the effects of HRQOL on death. Researchers took 10 other factors into account, including some of the biggest influences on death risk, such as smoking, diabetes control, and the presence of certain diabetes problems. But other factors, such as depression, were not considered and may have influenced death risk among subjects. Finally, researchers learned that poorer HRQOL is linked to higher death risk, but they did not look at the causes of that link.

What are the implications of the study?

In patients with type 2 diabetes, it is important for health care providers to look beyond medical and lab data and regularly look at patients' quality of life. Improving HRQOL is important in itself, and its link to higher death risks makes it an even more important part of diabetes care. Further research is needed to learn whether this link is caused by problems that can be solved or whether it is a result of the overall burden of living with diabetes.

FOR MORE INFORMATION

Living with Diabetes
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Diabetes and Stress

Coping with Diabetes