The utility of the surprise question: A useful tool for identifying patients nearing the last phase of life? A systematic review and meta-analysis

Background: The surprise question is widely used to identify patients nearing the last phase of life. Potential differences in accuracy between timeframe, patient subgroups and type of healthcare professionals answering the surprise question have been suggested. Recent studies might give new insights. Aim: To determine the accuracy of the surprise question in predicting death, differentiating by timeframe, patient subgroup and by type of healthcare professional. Design: Systematic review and meta-analysis. Data sources: Electronic databases PubMed, Embase, Cochrane Library, Scopus, Web of Science and CINAHL were searched from inception till 22nd January 2021. Studies were eligible if they used the surprise question prospectively and assessed mortality. Sensitivity, specificity, negative predictive value, positive predictive value and c-statistic were calculated. Results: Fifty-nine studies met the inclusion criteria, including 88.268 assessments. The meta-analysis resulted in an estimated sensitivity of 71.4% (95% CI [66.3–76.4]) and specificity of 74.0% (95% CI [69.3–78.6]). The negative predictive value varied from 98.0% (95% CI [97.7–98.3]) to 88.6% (95% CI [87.1–90.0]) with a mortality rate of 5% and 25% respectively. The positive predictive value varied from 12.6% (95% CI [11.0–14.2]) with a mortality rate of 5% to 47.8% (95% CI [44.2–51.3]) with a mortality rate of 25%. Seven studies provided detailed information on different healthcare professionals answering the surprise question. Conclusion: We found overall reasonable test characteristics for the surprise question. Additionally, this study showed notable differences in performance within patient subgroups. However, we did not find an indication of notable differences between timeframe and healthcare professionals.