A diagnostic model for impending death in cancer patients: Preliminary report

Abstract

Background: Several highly specific bedside physical signs associated with impending death within 3 days for patients with advanced cancer were recently identified. A diagnostic model for impending death based on these physical signs was developed and assessed.

Methods: Sixty-two physical signs were systematically documented every 12 hours from admission to death or discharge for 357 patients with advanced cancer who were admitted to acute palliative care units (APCUs) at 2 tertiary care cancer centers. Recursive partitioning analysis was used to develop a prediction model for impending death within 3 days with admission data. The model was validated with 5 iterations of 10-fold cross-validation, and the model was also applied to APCU days 2 to 6.

Results: For the 322 of 357 patients (90%) with complete data for all signs, the 3-day mortality rate was 24% on admission. The final model was based on 2 variables (Palliative Performance Scale [PPS] and drooping of nasolabial folds) and had 4 terminal leaves: PPS score ≤ 20% and drooping of nasolabial folds present, PPS score ≤ 20% and drooping of nasolabial folds absent, PPS score of 30% to 60%, and PPS score ≥ 70%. The 3-day mortality rates were 94%, 42%, 16%, and 3%, respectively. The diagnostic accuracy was 81% for the original tree, 80% for cross-validation, and 79% to 84% for subsequent APCU days.

Conclusions: Based on 2 objective bedside physical signs, a diagnostic model was developed for impending death within 3 days. This model was applicable to both APCU admission and subsequent days. Upon further external validation, this model may help clinicians to formulate the diagnosis of impending death.

Keywords: death; diagnosis; mortality; neoplasms; palliative care; physical examination.

Figure 1. Drooping of Nasolabial Fold

(A) Nasolabial folds are the skin folds that run from the nose to corners of the mouth (arrow). (B) In the last days of life, drooping of nasolabial fold may be noted in which they become less prominent because of the loss of facial muscle tone. The face appears to be more relaxed.

Figure 2. Recursive Partitioning Model for Impending Death in 3 Days

The main model (exclude bottom level) is based on 2 variables (drooping of nasolabial fold and palliative performance scale) and has 2 levels and 4 leaves. The diagnostic accuracy was 81%. Inclusion of the variable “number of late signs” resulted in a 6-leaf model that included 3 variables and 3 levels. The diagnostic accuracy was 82%. For each node, the number of patients that fulfill the criteria is shown along with the 3-day mortality rate (in parentheses).

Figure 3. Decreasing palliative performance status and increasing number of late signs were associated with an increased probability of death in 3 days

We plotted the (A) palliative performance status, and (B) number of late signs against a moving-average estimate of the probability of death in 3 days (y-axis).