The Waterlow score for risk assessment in surgical patients

Abstract

IntroductionPerioperative scoring systems aim to predict outcome following surgery and are used in preoperative counselling to guide management and to facilitate internal or external audit. The Waterlow score is used prospectively in many UK hospitals to stratify the risk of decubitus ulcer development. The primary aim of this study was to assess the potential value of this existing scoring system in the prediction of mortality and morbidity in a general surgical and vascular cohort.MethodsA total of 101 consecutive moderate to high risk emergency and elective surgical patients were identified through a single institution database. The preoperative Waterlow score and outcome data pertaining to that admission were collected. The discriminatory power of the Waterlow score was compared against that of the American Society of Anesthesiologists (ASA) grade and the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM).ResultsThe inpatient mortality rate was 17% and the 30-day morbidity rate was 29%. A statistically significant association was demonstrated between the preoperative Waterlow score and inpatient mortality (p<0.0001) and 30-day morbidity (p=0.0002). Using a threshold Waterlow score of 20 to dichotomise risk, accuracies of 0.84 and 0.76 for prediction of mortality and morbidity were demonstrated. In comparison with P-POSSUM, the preoperative Waterlow score performed well on receiver operating characteristic analysis. With respect to mortality, the area under the curve was 0.81 (0.80–0.85) and for morbidity it was 0.72 (0.69–0.76). The ASA grade achieved a similar level of discrimination.ConclusionsThe Waterlow score is collected routinely by nursing staff in many hospitals and might therefore be an attractive means of predicting postoperative morbidity and mortality. It might also function to stratify perioperative risk for comparison of surgical outcome data. A prospective study comparing these risk prediction scores is required to support these findings.

Waterlow score as a surrogate marker for predicting adverse outcome in acute pancreatitis

“…The Waterlow score was first introduced in 1985 as a tool to screen for patients at risk of developing decubitus ulcers during inpatient stays. 14,15 Its use has since become accepted as a standard of care in the majority of UK hospitals. 14,19 Pressure ulcer prevention remains a priority for nursing staff and as a result, there is a strong drive to record Waterlow scores for all patients on admission.…”

“…14,15 In our institution, there is a protocol driven target of 100% of patients having their scores recorded within six hours of admission. Previous reports have suggested that the Waterlow score correlates with disease severity and outcome in acute surgical emergencies.…”

“…Previous reports have suggested that the Waterlow score correlates with disease severity and outcome in acute surgical emergencies. [15][16][17] This study sought to establish whether this score might be an effective surrogate tool for assessing the severity of acute pancreatitis, risk of associated disease specific complications, need for escalation of treatment and, finally, mortality risk.…”

Validating a benchmarking tool for audit of early outcomes after operations for head and neck cancer

“…A high preoperative Waterlow score has previously been found to be associated with increased postoperative morbidity. 5 In terms of its utility for the risk algorithm, the Waterlow score looks promising as it appears to correlate with risk on initial testing. However, some discrimination will be lost through surgical case selection.…”

“…3 Data pertaining to patient demographics, indices of functional status, tumour stage, and operative and anaesthetic treatment were also included in the audit for the purpose of further model development. The Waterlow score, which has been shown to be useful as a means of predicting postoperative morbidity, 5 was tested for consideration of incorporation in a future scoring system.…”