Predictive Scores Underestimate Survival of Patients With Metastatic Spine Disease: A Retrospective Study of 315 Patients in Sweden

Study Design: Retrospective cohort study.

Objective: To validate the precision of four predictive scoring systems for spinal metastatic disease and evaluate whether they underestimate or overestimate survival.

Summary Of Background Data: Metastatic spine disease is a common complication to malignancies. Several scoring systems are available to predict survival and to help the clinician to select surgical or nonsurgical treatment.

Methods: Three hundred fifteen adult patients (213 men, 102 women, mean age 67 yr) undergoing spinal surgery at Uppsala University Hospital, Sweden, due to metastatic spine disease 2006 to 2012 were included. Data were collected prospectively for the Swedish Spine Register and retrospectively from the medical records. Tokuhashi scores, Revised Tokuhashi Scores, Tomita scores, and Modified Bauer Scores were calculated and compared with actual survival data from the Swedish Population Register.

Results: The mean estimated survival time after surgery for all patients included was 12.4 months (confidence interval 10.6-14.2) and median 5.9 months (confidence interval 4.5-7.3). All four scores had significant correlation to survival (P < 0.0001) but tended to underestimate rather than overestimate survival. Modified Bauer Score was the best of the four scores to predict short survival, both regarding median and mean survival. Tokuhashi score was found to be the best of the scores to predict long survival, even though the predictions were inaccurate in 42% of the cases.

Conclusion: Predictive scores underestimate survival for the patients which might affect important clinical decisions.

Level Of Evidence: 3.