Physicians’ predictions after disabling stroke too imprecise, researchers say

Physician predictions are an important factor in families’ decisions about end-of-life care for relatives. But how often are doctors wrong?

Dutch researchers analyzed this topic in a study of 60 patients who had suffered disabling stroke. Physicians predicted mortality, functional outcome and quality of life at six months post-stroke, and researchers compared those estimates with actual outcomes.

Of the 15 patients who were predicted to die, one survived at six months. Of the 30 patients who survived, one was predicted to die. Four patients estimated to have an unfavorable functional outcome had a favorable outcome, and physicians were only 63 percent accurate in predicting non-satisfactory quality of life.

While the doctors predicted these outcomes correctly in most patients, the researchers wrote “the false positive rate of a predicted poor outcome should preferably be zero” in these cases. Too much is riding on the prognostications, they explained in PLOS One.

“If an expected negative outcome (death, unfavorable functional outcome or a non-satisfactory quality of life) is used as a basis for treatment restrictions, the predictive accuracy should be very high to prevent unfounded pessimism which can lead to early withdrawal of treatment in a patient that otherwise could have recovered,” wrote lead researcher Marjolein Geurts, MD, from the department of neurology and neurosurgery at University Medical Center Utrecht, and colleagues.

“In our opinion, the predictive accuracy of physicians is insufficient to serve as the sole basis of decisions to limit treatment. Physicians should be aware of prognostic uncertainties and their consequences when discussing end-of-life decisions.”

Twenty-one neurology residents, supervised by 14 stroke neurologists, filled out questionnaires with six-month predictions for the patients. The patients available for follow-up were seen by a trained investigator who was unaware of the prognoses and assessed for functional outcome and quality of life.

The authors noted 44 percent of patients showed the physicians’ exact prediction of functional outcome, measured 0-6 on the modified Rankin scale. Of the predictions that were incorrect, 73 percent were too optimistic.

They also pointed out physicians were least accurate in predicting quality of life, which can be explained partially by factors unrelated to the severity of the disability—such as social or emotional support—that are difficult to identify during admission.

“Patients often report greater happiness and quality of life than healthy people predict they would feel under the same circumstances, a phenomenon often referred to as a ‘disability paradox,’ which is explained in part by the capacity of patients with chronic illness or disability to adapt to their circumstances,” Geurts and colleagues wrote.

The study’s findings can’t be generalized to all stroke patients. Only patients with severe disability four days after the stroke were included because those individuals are the most likely to encounter decisions about treatment restrictions. In addition, only a small number of patients were alive and available for quality of life assessment in follow-up, limiting statistical significance.

“Future research should focus on how to improve predictive accuracy, for example by using a combination of ‘mathematical’ prediction models and physicians’ prognostic estimates, and on how to identify in the acute stage after stroke patients who will recapture a good quality of life despite poor functional outcome,” the researchers suggested.