Accuracy of clinical prediction rules in peptic ulcer perforation: an observational study

Outcomes of Nonoperative Treatment for Gastroduodenal Ulcer Perforation: a Nationwide Study of 14,918 Inpatients in Japan

BACKGROUND

Gastroduodenal ulcer perforation is a common abdominal emergency that may be curable without surgical repair in non-elderly patients with localized and stable symptoms. However, the outcomes of nonoperative approaches have rarely been described.

METHODS

Using a Japanese national inpatient database, we identified 14,918 patients with gastroduodenal ulcer perforation who were hospitalized and received nonoperative treatment from July 2010 to March 2017. We categorized these patients into three groups according to age: 18 to 64 years (young group, n=8407), 65 to 74 years (old group, n=2616), and ≥75 years (old-old group, n=3895). We investigated the characteristics, treatments, and outcomes in each group.

RESULTS

Most of the patients were men (71%), and the median patient age was 62 years (interquartile range, 47-75 years). The old and old-old groups had more comorbidities than the young group. Whereas most patients were administered proton pump inhibitors and various antibiotics (96% and 90%, respectively), only 58% of patients underwent gastric tube placement. Surgical repair >3 days after admission was performed in 7.1% of all patients (6.3% vs. 7.9% vs. 5.5%, P<0.001). The old and old-old groups showed higher mortality (1.4% vs. 8.3% vs. 18%, P<0.001) and morbidity (6.6% vs. 15% vs. 17%, P<0.001) than the young group. The median length of stay was almost 2 weeks (13 vs. 17 vs. 20 days, P<0.001).

DISCUSSION

Unlike previous studies, many patients aged >65 years received nonoperative treatment in this nationwide cohort. Our findings provide useful information for clinicians and patients hospitalized for gastric ulcer perforation.

New machine learning scoring system for predicting postoperative mortality in gastroduodenal ulcer perforation: A study using a Japanese nationwide inpatient database

BACKGROUND

Conventional prediction models for estimating risk of postoperative mortality in gastroduodenal ulcer perforation have suboptimal prediction ability. We aimed to develop and validate new machine learning models and an integer-based score for predicting the postoperative mortality.

METHODS

We retrospectively identified patients with gastroduodenal ulcer perforation who underwent surgical repair, using a nationwide Japanese inpatient database. In a derivation cohort from July 2010 to March 2016, we developed 2 machine learning-based models, Lasso and XGBoost, using 45 candidate predictors, and also developed an integer-based score for clinical use by including important variables in Lasso. In a validation cohort from April 2016 to March 2017, we measured the prediction performances of the models by computing area under the curve and comparing it to the conventional American Society of Anesthesiology risk score.

RESULTS

Of 25,886 patients, 1,176 (4.5%) died after surgical repair. For the validation cohort, Lasso and XGBoost had significantly higher prediction abilities than the American Society of Anesthesiology score (Lasso area under the curve = 0.84; 95% confidence interval 0.81-0.86; American Society of Anesthesiology score area under the curve = 0.70; 95% confidence interval 0.65-0.74, P < .001). The integer-based risk score, which had 13 factors, had a prediction ability similar to those of Lasso and XGBoost (area under the curve = 0.83; 95% confidence interval 0.81-0.86). According to the integer-based score, the mortalities were 0.1%, 2.3%, 9.3%, and 29.0% for the low (score, 0), moderate (1-2), high (3-4), and very high (≥5) score groups, respectively.

CONCLUSION

Machine learning models and the integer-based risk score performed well in predicting risk of postoperative mortality in gastroduodenal ulcer perforation. These models will help in decision making.

A Fast and Reliable Method to Interpret Short-Term Mortality in Perforated Peptic Ulcer: Red Cell Distribution Width is Sensitive and Specific

Introduction

Peptic ulcer is an important health problem worldwide with a prevalence of around 5%. Peptic ulcer perforation is a potentially mortal complication of peptic ulcer disease. We aimed to investigate the potential use of red cell distribution width as a prognostic marker in peptic ulcer perforation.

Methods

The files, operation notes, biochemical and hematological parameters, and prognosis of patients who were operated for a peptic ulcer perforation were reviewed in a retrospective cohort study. The relation of red cell distribution width (RDW) to main outcome in-hospital mortality was assessed.

Results

The mean age of the 172 patients was 40 ± 17.89. There were 158 (92%) males and 14 (8%) females. The in-hospital mortality was 8.7% (15/172). The median RDW in the group with mortality was 15.00 (interquartile range (IQR): 14.30–17.20) compared with the median RDW in the group with no mortality as 13.2 (IQR: 12.80–14.00, p ≤ 0.001). Receiver operator characteristic curves were plotted for RDW to identify nonsurvivors and yielded a significant area under the curve as 0.812 (95% confidence interval: 0.682–0.942). The sensitivity and specificity of RDW at a cutoff value of 14.25% were calculated with an accuracy of 81.98 (95% confidence interval: 75.40–87.41) as 80.00 (51.91–95.67) and 82.17 (75.27–87.81), respectively.

Conclusion

Increased RDW may be of use to interpret mortality in patients with peptic ulcer perforation.

Evaluating and improving current risk prediction tools in emergency laparotomy

PURPOSE

Emergency laparotomy (EL) encompasses a high-risk group of operations, which are increasingly performed on a heterogeneous population of patients, making preoperative risk assessment potentially difficult. The UK National Emergency Laparotomy Audit (NELA) recently produced a risk predictive tool for EL that has not yet been externally validated. We aimed to externally validate and potentially improve the NELA tool for mortality prediction after EL.

METHODOLOGY

We reviewed computer and paper records of EL patients from May 2012 to June 2017 at Middlemore Hospital (New Zealand). The inclusion criteria mirrored the UK NELA. We examined the NELA, Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality (P-POSSUM), Acute Physiology and Chronic Health Evaluation II (APACHE-II), and American College of Surgeons National Surgical Quality Improvement Programs risk predictive tools for 30-day mortality. The Hosmer-Lemeshow test was used to assess calibration, and the c statistic, to evaluate discrimination (accuracy) of the tools. We added the modified frailty index (mFI) and nutrition to improve the accuracy of risk predictive tools.

RESULTS

A total of 758 patients met the inclusion criteria, with an observed 30-day mortality of 7.9%. The NELA was the only well calibrated tool, with predicted 30-day mortality of 7.4% (p = 0.22). When combined with mFI and nutritional status, the c statistic for NELA improved from 0.83 to 0.88. American College of Surgeons National Surgical Quality Improvement Programs, APACHE-II, and P-POSSUM had lower c statistics, albeit also showing an improvement (0.84, 0.81, and 0.74, respectively).

CONCLUSION

We have demonstrated the NELA tool to be most predictive of mortality after EL. The NELA tool would therefore facilitate preoperative risk assessment and operative decision making most precisely in EL. Future research should consider adding mFI and nutritional status to the NELA tool.

LEVEL OF EVIDENCE

Level IV; Retrospective observational cohort study.

Assessment of PULP score in predicting 30-day perforated duodenal ulcer morbidity, and comparison of its performance with Boey and ASA, a retrospective study

Background

/aim: Scores commonly employed to risk stratify perforated peptic ulcer patients include ASA (American Society of Anesthesiologists), Boey and peptic ulcer perforation score (PULP). However, few studies assessed and compared the accuracy indices of these three scores in predicting post PPU repair 30-day morbidity. We assessed accuracy indices of PULP, and compared them to Boey and ASA in predicting post perforated duodenal (PDU) ulcer repair 30-day morbidity.

Methods

Retrospective chart review of all PDU patients (perforated duodenal ulcers only) at the largest two hospitals in Qatar (N = 152). Data included demographic, clinical, laboratory, operative, and post repair 30-day morbidity. Area under the Curve (AUC), sensitivity and specificity were computed for each of the 3 scores. Multivariate logistic regression assessed the accuracy indices of each score.

Results

All patients were males (M age 37.41 years). Post PDU repair 30-day morbidity was 10.5% (16 morbidities). Older age, higher ASA (≥3), Boey (≥1) or PULP (≥8) scores, shock on admission and preoperative comorbidities; and conversely, lower hemoglobin and albumin were all positively significantly associated with higher post PDU 30-day morbidity. PULP displayed the largest AUC (72%), and was the only score to significantly predict 30-day morbidity. The current study is the first to report the sensitivity and specificity of these three scores for post PDU repair 30-day morbidity; and first to assess accuracy indices for PULP in predicting post PDU repair 30-day morbidity.

Conclusion

PULP score had the largest AUC and was the only score to significantly predict post PDU repair 30-day morbidity.

•

The current study is the first to report the sensitivity and specificity of the three scoring systems (ASA, Boey and PULP) for post perforated duodenal ulcer repair 30-day morbidity.

•

It is also the first study to assess accuracy indices for PULP in predicting post perforated duodenal ulcer repair 30-day morbidity.

•

Compared with ASA and Boey, PULP score had the largest area under the curve and was the only score to significantly predict post perforated duodenal ulcer repair 30-day morbidity.

Patients With Perforated Peptic Ulcers: Risk Factors for Morbidity and Mortality

Perforated peptic ulcers continue to be an important problem in surgical practice. In this study, risk factors for peptic ulcer perforation-associated mortality and morbidity were evaluated. This is a retrospective study of patients surgically treated for perforated peptic ulcer over a decade (March 1999–December 2014). Patient age, sex, complaints at presentation, time lapse between onset of complaints and presentation to the hospital, physical findings, comorbidities, laboratory and imaging findings, length of hospitalization, morbidity, and mortality were recorded. The Mannheim peritonitis index (MPI) and Acute Physiology and Chronic Health Evaluation (APACHE) II score were calculated and recorded for each patient on admission to the hospital. Of the 149 patients, mean age was 50.6 ± 19 years (range: 17–86). Of these, 129 (86.5%) were males and 20 (13.4%) females. At least 1 comorbidity was found in 42 (28.1%) of the patients. Complications developed in 36 (24.1%) of the patients during the postoperative period. The most frequent complication was wound site infection. There was mortality in 26 (17.4%) patients and the most frequent cause of mortality was sepsis. Variables that were found to have statistically significant effects on morbidity included age older than 60 years, presence of comorbidities, and MPI (P = 0.029, 0.013, and 0.013, respectively). In a multivariate analysis, age older than 60 years, presence of comorbidities, and MPI were independent risk factors that affected morbidity. In the multivariate logistic regression analysis, age older than 60 years [P = 0.006, odds ratio (OR) = 5.99, confidence interval (CI) = 0.95] and comorbidities (OR = 2.73, CI = 0.95) were independent risk factors that affected morbidity. MPI and APACHE II scoring were both predictive of mortality. Age older than 60, presentation time, and MPI were independent risk factors for mortality. Undelayed diagnosis and appropriate treatment are of the utmost importance when presenting with a perforated peptic ulcer. We believe close observation of high-risk patients during the postoperative period may decrease morbidity and mortality rates.

Risk factors for reintervention after surgery for perforated gastroduodenal ulcer

Background

Perforated gastroduodenal ulcer carries a high mortality rate. Need for reintervention after surgical repair is associated with worse outcome, but knowledge on risk factors for reintervention is limited. The aim was to identify prognostic risk factors for reintervention after perforated gastroduodenal ulcer in a nationwide cohort.

Methods

All patients treated surgically for perforated gastroduodenal ulcer in Denmark between 2003 and 2014 were included using data from the Danish Clinical Register of Emergency Surgery. Potential risk factors for reintervention were assessed, and their crude and adjusted associations calculated by the competing risks subdistribution hazards approach.

Results

A total of 4086 patients underwent surgery for perforated gastroduodenal ulcer during the study interval. Median age was 71·1 (i.q.r. 59·6–81·0) years and the overall 90-day mortality rate was 30·8 per cent (1258 of 4086). Independent risk factors for reintervention were: male sex (adjusted hazard ratio (HR) 1·46, 95 per cent c.i. 1·20 to 1·78), in-hospital perforation (adjusted HR 1·36, 1·11 to 1·68), high BMI (adjusted HR 1·49, 1·10 to 2·01), high ASA physical status grade (adjusted HR 1·54, 1·23 to 1·94), shock on admission (adjusted HR 1·40, 1·13 to 1·74), surgical delay (adjusted HR 1·07, 1·02 to 1·14) and other co-morbidity (adjusted HR 1·24, 1·02 to 1·51). Preadmission use of steroids (adjusted HR 0·59, 0·41 to 0·84) and age above 70 years (adjusted HR 0·72, 0·59 to 0·89) were associated with a reduced risk of reoperation.

Conclusion

Obese men with coexisting diseases and high disease severity who have surgery for gastroduodenal perforation are at increased risk of reoperation.

Postoperative Morbidity and Mortality of Perforated Peptic Ulcer: Retrospective Cohort Study of Risk Factors among Black Africans in Côte d'Ivoire

Introduction. Surgical treatment of perforated peptic ulcer (PPU) is a challenge for surgeons in Africa. Aim. To determine risk factors of postoperative complications or mortality among black Ivoirian patients with PPU. Methods. All 161 patients (median age = 34 years, 90.7 male) operated on for PPU in the visceral and general surgery unit were enrolled in a retrospective cohort study. Variables were studied with Kaplan Meier and Cox proportional hazard models. Results. Among 161 patients operated on for PPU, 36 (27.5%) experienced complications and 31 (19.3%) died. Follow-up results were the incidence of complications and mortality of 6.4 (95% CI: 4.9–8.0) per 100 person-days and 3.0 (95% CI: 1.9–4.0) per 100 person-days for incidence of mortality. In multivariate analysis, risk factors of postoperative complications or mortality were comorbidities (HR = 2.1, P = 0.03), tachycardia (pulse rate > 100/minutes) (HR = 2.4, P = 0.02), purulent intra-abdominal fluid collection (HR = 2.1, P = 0.04), hyponatremia (median value ≤ 134 mEq/L) (HR = 2.3, P = 0.01), delayed time of hospital admission > 72 hours (HR = 2.6, P < 0.0001), and delayed time of surgical intervention between 24 and 48 hours (HR = 3.8, P < 0.0001). Conclusion. The delayed hospital admission or surgical intervention and hyponatremia may be considered as additional risk of postoperative complications or mortality in Black African patients with PPU.

Risk assessment tools validated for patients undergoing emergency laparotomy: a systematic review

Emergency laparotomies are performed commonly throughout the world, but one in six patients die within a month of surgery. Current international initiatives to reduce the considerable associated morbidity and mortality are founded upon delivering individualised perioperative care. However, while the identification of high-risk patients requires the routine assessment of individual risk, no method of doing so has been demonstrated to be practical and reliable across the commonly encountered spectrum of presentations, co-morbidities and operative procedures. A systematic review of Embase and Medline identified 20 validation studies assessing 25 risk assessment tools in patients undergoing emergency laparotomy. The most frequently studied general tools were APACHE II, ASA-PS and P-POSSUM. Comparative, quantitative analysis of tool performance was not feasible due to the heterogeneity of study design, poor reporting and infrequent within-study statistical comparison of tool performance. Reporting of calibration was notably absent in many prognostic tool validation studies. APACHE II demonstrated the most consistent discrimination of individual outcome across a variety of patient groups undergoing emergency laparotomy when used either preoperatively or postoperatively (area under the curve 0.76-0.98). While APACHE systems were designed for use in critical care, the ability of APACHE II to generate individual risk estimates from objective, exclusively preoperative data items may lead to better-informed shared decisions, triage and perioperative management of patients undergoing emergency laparotomy. Future endeavours should include the recalibration of APACHE II and P-POSSUM in contemporary cohorts, modifications to enable prediction of morbidity and assessment of the impact of adoption of these tools on clinical practice and patient outcomes.

Perforated peptic ulcer

Perforated peptic ulcer is a common emergency condition worldwide, with associated mortality rates of up to 30%. A scarcity of high-quality studies about the condition limits the knowledge base for clinical decision making, but a few published randomised trials are available. Although Helicobacter pylori and use of non-steroidal anti-inflammatory drugs are common causes, demographic differences in age, sex, perforation location, and underlying causes exist between countries, and mortality rates also vary. Clinical prediction rules are used, but accuracy varies with study population. Early surgery, either by laparoscopic or open repair, and proper sepsis management are essential for good outcome. Selected patients can be managed non-operatively or with novel endoscopic approaches, but validation of such methods in trials is needed. Quality of care, sepsis care bundles, and postoperative monitoring need further assessment. Adequate trials with low risk of bias are urgently needed to provide better evidence. We summarise the evidence for perforated peptic ulcer management and identify directions for future clinical research.

A practical scoring system to predict mortality in patients with perforated peptic ulcer

Introduction

The mortality rate of perforated peptic ulcer is still high particularly for aged patients and all the existing scoring systems to predict mortality are complicated or based on history taking which is not always reliable for elderly patients. This study’s aim was to develop an easy and applicable scoring system to predict mortality based on hospital admission data.

Methods

Total 227 patients operated for perforated peptic ulcer in two centers were included. All data that may be potential predictors with respect to hospital mortality were retrospectively analyzed.

Results

The mortality and morbidity rates were 10.1% and 24.2%, respectively. Multivariated analysis pointed out three parameters corresponding 1 point for each which were age >65 years, albumin ≤1,5 g/dl and BUN >45 mg/dl. Its prediction rate was high with 0,931 (95% CI, 0,890 to 0,961) value of AUC. The hospital mortality rates for none, one, two and three positive results were zero, 7.1%, 34.4% and 88.9%, respectively.

Conclusion

Because the new system consists only age and routinely measured two simple laboratory tests (albumin and BUN), its application is easy and prediction power is satisfactory. Verification of this new scoring system is required by large scale multicenter studies.

Five year experience in management of perforated peptic ulcer and validation of common mortality risk prediction models - are existing models sufficient? A retrospective cohort study

BACKGROUND

Emergency surgery for perforated peptic ulcer (PPU) is associated with significant morbidity and mortality. Accurate and early risk stratification is important. The primary aim of this study is to validate the various existing MRPMs and secondary aim is to audit our experience of managing PPU.

METHODS

332 patients who underwent emergency surgery for PPU at a single intuition from January 2008 to December 2012 were studied. Clinical and operative details were collected. Four MRPMs: American Society of Anesthesiology (ASA) score, Boey's score, Mannheim peritonitis index (MPI) and Peptic ulcer perforation (PULP) score were validated.

RESULTS

Median age was 54.7 years (range 17-109 years) with male predominance (82.5%). 61.7% presented within 24 h of onset of abdominal pain. Median length of stay was 7 days (range 2-137 days). Intra-abdominal collection, leakage, re-operation and 30-day mortality rates were 8.1%, 2.1%, 1.2% and 7.2% respectively. All the four MRPMs predicted intra-abdominal collection and mortality; however, only MPI predicted leak (p = 0.01) and re-operation (p = 0.02) rates. The area under curve for predicting mortality was 75%, 72%, 77.2% and 75% for ASA score, Boey's score, MPI and PULP score respectively.

DISCUSSION AND CONCLUSION

Emergency surgery for PPU has low morbidity and mortality in our experience. MPI is the only scoring system which predicts all - intra-abdominal collection, leak, reoperation and mortality. All four MRPMs had a similar and fair accuracy to predict mortality, however due to geographic and demographic diversity and inherent weaknesses of exiting MRPMs, quest for development of an ideal model should continue.

Risk factors influencing morbidity and mortality in perforated peptic ulcer disease

OBJECTIVE

Peptic ulcer perforation continues to be a major surgical problem. In this study, risk factors that influence morbidity and mortality in perforated peptic ulcer disease were examined.

MATERIAL AND METHODS

Files of 148 patients who were included in the study due to peptic ulcer perforation between January 2006 and December 2010 were retrospectively analyzed. Data regarding age, gender, complaints, time elapsed between onset of symptoms and hospital admission, physical examination findings, co-morbid diseases, laboratory and imaging findings, length of hospital stay, morbidity and mortality were recorded.

RESULTS

The study group included 129 (87.2%) male and 19 (12.8%) female patients. The mean age was 51.7±20 (15-88) years. Forty five patients (30.4%) had at least one co-morbid disease. In the postoperative period, 30 patients (20.3%) had complications. The most common complication was wound infection. Mortality was observed in 27 patients (18.2%). The most common cause of mortality was sepsis. Multivariate analysis revealed age over 60 years, presence of co-morbidities and Mannheim peritonitis index as independent risk factors for morbidity. Age over 60 years, time to admission and Mannheim peritonitis index were detected as independent risk factors for mortality.

CONCLUSION

Early diagnosis and proper treatment are important in patients presenting with peptic ulcer perforation.

What is the best predictor of mortality in perforated peptic ulcer disease? A population-based, multivariable regression analysis including three clinical scoring systems

BACKGROUND

Mortality rates in perforated peptic ulcer (PPU) have remained unchanged. The aim of this study was to compare known clinical factors and three scoring systems (American Society of Anesthesiologists (ASA), Boey and peptic ulcer perforation (PULP)) in the ability to predict mortality in PPU.

MATERIAL AND METHODS

This is a consecutive, observational cohort study of patients surgically treated for perforated peptic ulcer over a decade (January 2001 through December 2010). Primary outcome was 30-day mortality.

RESULTS

A total of 172 patients were included, of whom 28 (16 %) died within 30 days. Among the factors associated with mortality, the PULP score had an odds ratio (OR) of 18.6 and the ASA score had an OR of 11.6, both with an area under the curve (AUC) of 0.79. The Boey score had an OR of 5.0 and an AUC of 0.75. Hypoalbuminaemia alone (≤37 g/l) achieved an OR of 8.7 and an AUC of 0.78. In multivariable regression, mortality was best predicted by a combination of increasing age, presence of active cancer and delay from admission to surgery of >24 h, together with hypoalbuminaemia, hyperbilirubinaemia and increased creatinine values, for a model AUC of 0.89.

CONCLUSION

Six clinical factors predicted 30-day mortality better than available risk scores. Hypoalbuminaemia was the strongest single predictor of mortality and may be included for improved risk estimation.

Strategies to improve the outcome of emergency surgery for perforated peptic ulcer

BACKGROUND

Perforated peptic ulcer (PPU) is a common surgical emergency that carries high mortality and morbidity rates. Globally, one-quarter of a million people die from peptic ulcer disease each year. Strategies to improve outcomes are needed.

METHODS

PubMed was searched for evidence related to the surgical treatment of patients with PPU. The clinical registries of trials were examined for other available or ongoing studies. Randomized clinical trials (RCTs), systematic reviews and meta-analyses were preferred.

RESULTS

Deaths from peptic ulcer disease eclipse those of several other common emergencies. The reported incidence of PPU is 3.8-14 per 100,000 and the mortality rate is 10-25 per cent. The possibility of non-operative management has been assessed in one small RCT of 83 patients, with success in 29 (73 per cent) of 40, and only in patients aged less than 70 years. Adherence to a perioperative sepsis protocol decreased mortality in a cohort study, with a relative risk (RR) reduction of 0.63 (95 per cent confidence interval (c.i.) 0.41 to 0.97). Based on meta-analysis of three RCTs (315 patients), laparoscopic and open surgery for PPU are equivalent, but patient selection remains a challenge. Eradication of Helicobacter pylori after surgical repair of PPI reduces both the short-term (RR 2.97, 95 per cent c.i. 1.06 to 8.29) and 1-year (RR 1.49, 1.10 to 2.03) risk of ulcer recurrence.

CONCLUSION

Mortality and morbidity from PPU can be reduced by adherence to perioperative strategies.

Scoring systems for outcome prediction in patients with perforated peptic ulcer

Background

Patients with perforated peptic ulcer (PPU) often present with acute, severe illness that carries a high risk for morbidity and mortality. Mortality ranges from 3-40% and several prognostic scoring systems have been suggested. The aim of this study was to review the available scoring systems for PPU patients, and to assert if there is evidence to prefer one to the other.

Material and methods

We searched PubMed for the mesh terms “perforated peptic ulcer”, “scoring systems”, “risk factors”, ”outcome prediction”, “mortality”, ”morbidity” and the combinations of these terms. In addition to relevant scores introduced in the past (e.g. Boey score), we included recent studies published between January 2000 and December 2012) that reported on scoring systems for prediction of morbidity and mortality in PPU patients.

Results

A total of ten different scoring systems used to predict outcome in PPU patients were identified; the Boey score, the Hacettepe score, the Jabalpur score the peptic ulcer perforation (PULP) score, the ASA score, the Charlson comorbidity index, the sepsis score, the Mannheim Peritonitis Index (MPI), the Acute physiology and chronic health evaluation II (APACHE II), the simplified acute physiology score II (SAPS II), the Mortality probability models II (MPM II), the Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity physical sub-score (POSSUM-phys score). Only four of the scores were specifically constructed for PPU patients. In five studies the accuracy of outcome prediction of different scoring systems was evaluated by receiver operating characteristics curve (ROC) analysis, and the corresponding area under the curve (AUC) among studies compared. Considerable variation in performance both between different scores and between different studies was found, with the lowest and highest AUC reported between 0.63 and 0.98, respectively.

Conclusion

While the Boey score and the ASA score are most commonly used to predict outcome for PPU patients, considerable variations in accuracy for outcome prediction were shown. Other scoring systems are hampered by a lack of validation or by their complexity that precludes routine clinical use. While the PULP score seems promising it needs external validation before widespread use.