By Alison McCook
NEW YORK (Reuters Health) - People with incurable cancer are better able to predict how long they will survive than doctors using other, commonly used indications of disease prognosis, researchers report.
This innate ability indicates that "patients have a tremendous ability to use external and internal information to assess their own health," according to Dr. Paul Craft and colleagues from Canberra Hospital in Australia.
As such, Craft and his team recommend that doctors respect a patient's sense of their own health when making decisions about his or her care.
The investigators studied 181 patients with incurable cancer and asked the question, "In general, would you say your health is excellent, very good, good, fair, or poor?"
Patients were asked to rate their health at the beginning of the study, and also 18 weeks later, according to the report in the May 15th issue of the Journal of Clinical Oncology.
Ten months after the study began, one half of the patients had died. The measurement that best predicted how long patients would survive was their self-rated health, with lower ratings associated with shorter survival times, and higher ratings predicting a lower risk of death.
Those whose self-rated health went from good to fair or good to poor at 18 weeks were three and six times as likely to die, respectively, as those whose self-rated health was consistently good.
Self-rated health was the best predictor of how long patients would survive once the study began, beating out clinical indicators, performance status, appetite loss, and measures of quality of life related to their health, the report indicates.
In an interview with Reuters Health, Craft said the study only measured how well self-rated health predicts survival, and not whether a patient's perception of how healthy they are can, in turn, influence their health.
"It is possible self-rated health is reflecting some attributes of personality and coping mechanisms which may be important in determining outcome," he said.
But what influences self-rated health? That, said Craft, appears to stem from a patient's physical and mental health, lifestyle, symptoms and social circumstances.
"However, how people combine these factors to assess their health seems to be some sort of internal calculation that is beyond a simple addition of these factors," Craft noted.
"In other words, the individual adds some vital assessment over and above their objective health status that provides an accurate prediction of survival," he added.
SOURCE: Journal of Clinical Oncology 2002;20:2514-2519.