Forecasting is a perilous activity at the best of times, but in some professions, the forecasts have serious implications.  Nowhere is this more so than in healthcare, where physicians operating in the intensive care unit regularly make predictions about the prospects of a patient in their care.

A recent study examined the accuracy of these judgements, whilst also comparing the forecasts of nurses on the same ward.  The study reveals an interesting degree of variance in the accuracy of predictions.  For instance, physicians were much better at predicting the mortality rate of patients in six months time than they were that patient’s cognitive function.

“Our study showed that doctors’ accuracy in predicting what will happen to patients six months after leaving the ICU was quite good when the doctors were confident in those predictions, and even better when nurses agreed with them,” the authors say. “When deciding how to frame their prognostic judgments to patients or family members, ICU physicians should consider their own confidence level and their agreement, or lack thereof, with bedside nurses.”

Testing the medics

The study saw participating doctors and nurses quizzed on whether patients would die during their stay in hospital, or within a six month timeframe.  If the patient was predicted to survive beyond six months, the participants were then asked to predict whether they would be unable to: return to his or her original residence, use the toilet independently, climb ten steps independently, or function well cognitively (“remember most things, think clearly, and solve day-to-day problems”).

The accuracy was mixed, with doctors doing well in areas such as in-hospital mortality and six-month mortality.  Where they didn’t perform well however was in predicting cognitive dysfunction, although the authors are at pains to point out that this has always been difficult.

“Prior studies have also highlighted the difficulties, in some cases, of predicting future cognitive function. What this study suggests is that doctors can reveal their uncertainty to families about patients’ abilities to think clearly, while also confidently guiding families as to whether or not a patient will be able to go to the bathroom or even be alive,” they say.

The team believe their findings are crucial in helping doctors make wise and accurate forecasts about the future health of their patients, especially when patients are on life support for prolonged periods.

“These data are important,” the researchers say, “because nearly all families want to know what the doctors believe will happen, but doctors often fail to share their prognoses because they know that there’s no way to be 100 percent certain.”

Whilst, understandably, no doctors are ever going to be 100% accurate, the results do nonetheless show that they are pretty good at predicting the future wellbeing of the patient, and that these predictions are likely to be of help to families faced with incredibly difficult decisions about the long-term care of their loved ones.

The team hope to turn their attention next to understanding some of the factors that influence the decision making of doctors and nurses, and their impact on accurate predictions.