A new study published in the Journal of Happiness Studies found that the degree to which a disease disrupts daily functioning is associated with reduced happiness.

Lead author Erik Angner, associate professor of philosophy, economics and public policy at George Mason University, worked with an interdisciplinary team of researchers from the University of Alabama at Birmingham, the University of Chicago and the University of Massachusetts Medical School.

Previous research found that many serious medical conditions, including cancer, have a surprisingly small impact on happiness, while certain other conditions, such as urinary incontinence, seem to have a lasting negative effect on happiness.

In their study, Angner and his co-authors explored the difference. They developed a measure called the "freedom-from-debility score" based on four health survey questions explicitly designed to represent limitations in physical activities and in usual role activities because of health problems.

This study is the first to use a direct measure of the degree to which disease disrupts daily functioning.

The authors found that when controlling for demographic and socioeconomic factors in addition to objective and subjective health status, a one-point increase in the freedom-from-debility score (on a scale from 0 to 100) was associated with a three-percent reduction in the odds of reported unhappiness.

For example, a patient with prostate cancer, whose daily functioning is not affected by his condition, might score higher on a happiness scale than a patient with urinary incontinence, whose condition imposes dramatic limitations in daily functioning. Indeed, in an earlier study, the authors found that participants with a history of cancer reported being significantly happier than those with urinary incontinence.

The study was conducted using a sample of 383 older adults recruited from the practices of 39 primary care physicians in Alabama.

"These new results support the notion that health status is one of the most important predictors of happiness," Angner said. "A better understanding of the complex relationship between health status and subjective well-being could have important implications for the care and treatment of patients and could lead to interventions that could dramatically improve patient quality of life."

Angner has separate PhDs in economics and in history and philosophy of science and has written extensively on the philosophy and economics of health, happiness and well-being. He is the author of A Course in Behavioral Economics.