Accuracy of Clinicians' Prediction of Survival and Prognostic Factors Indicative of Survival: a Systematic Review

Objectives: To review the literature and examine the accuracy of clinicians' prediction of survival as well as prognostic factors determined to be predictive of shorter survival in terminal cancer patients. Methods: A literature search was conducted on MEDLINE (1 January 2000 to 29 July 2012), Embase (1 January 2000 to 22 July 2012), and Cochrane Database of Systematic Reviews (1 January 2005 to July 2012). Reference sections of relevant reviews were also examined for relevant articles. All studies examining the accuracy of prediction of survival and prognostic factors indicative of survival in patients with terminal cancer were selected. Descriptive statistics summarised the extracted data. Results: A total of 85 studies published from 1972 to July 2012 with a study cohort of 30 to 6066 patients were identified. Clinicians' prediction of survival correlated with patient's actual survival, but the predictions tended to be too optimistic. The ability of varying health care professionals to estimate survival was contradictory among different studies. Some studies noticed those with more experience with terminal cancer patients were better able to predict an accurate estimation, whereas others concluded that there was no difference. The estimations were also more accurate during short-term time ranges such as the 'horizon effect'. Only a few assessment tools to assist in predicting the remaining duration of survival in patients were validated. A variety of prognostic factors between studies were identified, but the factors were not validated nor any instruments created. Conclusion: Demographic information and clinical symptoms can assist in determining the remaining duration of survival of terminal cancer patients. Assessment tools should be convenient and not a burden for the patient as the goal of palliative care is to maintain or improve the quality of life as much as possible. Even with the application of instruments to formulate a prediction, error cannot be completely eliminated. Physicians should warn the patient and their family of the uncertainty of the predictions.