Novel Textbook Outcomes following emergency laparotomy: Delphi exercise.

BACKGROUND: Textbook outcomes are composite outcome measures that reflect the ideal overall experience for patients. There are many of these in the elective surgery literature but no textbook outcomes have been proposed for patients following emergency laparotomy. The aim was to achieve international consensus amongst experts and patients for the best Textbook Outcomes for non-trauma and trauma emergency laparotomy. METHODS: A modified Delphi exercise was undertaken with three planned rounds to achieve consensus regarding the best Textbook Outcomes based on the category, number and importance (Likert scale of 1-5) of individual outcome measures. There were separate questions for non-trauma and trauma. A patient engagement exercise was undertaken after round 2 to inform the final round. RESULTS: A total of 337 participants from 53 countries participated in all three rounds of the exercise. The final Textbook Outcomes were divided into 'early' and 'longer-term'. For non-trauma patients the proposed early Textbook Outcome was 'Discharged from hospital without serious postoperative complications (Clavien-Dindo ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation or death). For trauma patients it was 'Discharged from hospital without unexpected transfusion after haemostasis, and no serious postoperative complications (adapted Clavien-Dindo for trauma ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation on or death)'. The longer-term Textbook Outcome for both non-trauma and trauma was 'Achieved the early Textbook Outcome, and restoration of baseline quality of life at 1 year'. CONCLUSION: Early and longer-term Textbook Outcomes have been agreed by an international consensus of experts for non-trauma and trauma emergency laparotomy. These now require clinical validation with patient data.

The Prognostic Impact of Minimally Invasive Esophagectomy on Survival after Esophagectomy following a Delayed Interval after Chemoradiotherapy; A Secondary Analysis of the DICE Study.

OBJECTIVE: To evaluate prognostic differences between minimally invasive esophagectomy (MIE) and open esophagectomy (OE) in patients with surgery after a prolonged interval (>12 wk) following chemoradiotherapy (CRT). BACKGROUND: Previously, we established that a prolonged interval after CRT prior to esophagectomy was associated with poorer long-term survival. METHODS: This was an international multi-center cohort study involving seventeen tertiary centers, including patients who received CRT followed by surgery between 2010-2020. Patients undergoing MIE were defined as thoracoscopic and laparoscopic approach. RESULTS: 428 patients (145 MIE and 283 OE) had surgery between 12 weeks and two years after CRT. Significant differences were observed in ASA grade, radiation dose, clinical T stage, and histological subtype. There were no significant differences between the groups in age, sex, BMI, pathological T or N stage, resection margin status, tumor location, surgical technique, or 90-day mortality. Survival analysis showed MIE was associated with improved survival in univariate (P=0.014), multivariate analysis after adjustment for smoking, T and N stage, and histology (HR=1.69; 95% CI 1.14 to 2.5) and propensity matched analysis (P=0.02). Further subgroup analyses by radiation dose and interval after CRT showed survival advantage for MIE, in 40-50Gy dose groups (HR=1.9; 95% CI 1.2 to 3.0), and in patients having surgery within six months of CRT (HR=1.6; 95% CI 1.1 to 2.2). CONCLUSION: MIE was associated with an improved overall survival compared to OE in patients with a prolonged interval from CRT to surgery. The mechanism for this observed improvement in survival remains unknown, with potential hypotheses including a reduction in complications and improved functional recovery after MIE.

Navigating reflux disease after achalasia treatments: Balancing risks and benefits.

The peroral endoscopic myotomy (POEM) procedure has revolutionized the management of achalasia in many centres around the world as it offers patients a minimally invasive endoscopic solution to their dysphagia caused by achalasia. Alongside its success in alleviating dysphagia, concerns regarding postoperative gastroesophageal reflux disease have emerged as a pertinent issue which are not fully resolved. In this study, Nabi et al have comprehensively reviewed the topic of the prediction, prevention and management of gastroesophageal reflux after POEM. POEM is a purely endoscopic procedure which is usually performed without any anti-reflux procedure. Certain patients may be better served by a laparoscopic Heller's myotomy and fundoplication and it is important that gastroenterologists and surgeons provide comprehensive risks and benefits of each achalasia treatment option so that patients can decide what treatment is best for them. This article by Nabi et al provides a comprehensive review of the current status of this issue to allow these discussions to occur.

Predictors and Significance of Readmission after Esophagogastric Surgery: A Nationwide Analysis.

Objective: The aim of this study is to identify risk factors for readmission after elective esophagogastric cancer surgery and characterize the impact of readmission on long-term survival. The study will also identify whether the location of readmission to either the hospital that performed the primary surgery (index hospital) or another institution (nonindex hospital) has an impact on postoperative mortality. Background: Over the past decade, the center-volume relationship has driven the centralization of major cancer surgery, which has led to improvements in perioperative mortality. However, the impact of readmission, especially to nonindex centers, on long-term mortality remains unclear. Methods: This was a national population-based cohort study using Hospital Episode Statistics of adult patients undergoing esophagectomy and gastrectomy in England between January 2008 and December 2019. Results: This study included 27,592 patients, of which overall readmission rates were 25.1% (index 15.3% and nonindex 9.8%). The primary cause of readmission to an index hospital was surgical in 45.2% and 23.7% in nonindex readmissions. Patients with no readmissions had significantly longer survival than those with readmissions (median: 4.5 vs 3.8 years; P < 0.001). Patients readmitted to their index hospital had significantly improved survival as compared to nonindex readmissions (median: 3.3 vs 4.7 years; P < 0.001). Minimally invasive surgery and surgery performed in high-volume centers had improved 90-day mortality (odds ratio, 0.75; P < 0.001; odds ratio, 0.60; P < 0.001). Conclusion: Patients requiring readmission to the hospital after surgery have an increased risk of mortality, which is worsened by readmission to a nonindex institution. Patients requiring readmission to the hospital should be assessed and admitted, if required, to their index institution.

Predictors of anastomotic leak and conduit necrosis after oesophagectomy: Results from the oesophago-gastric anastomosis audit (OGAA).

BACKGROUND: Both anastomotic leak (AL) and conduit necrosis (CN) after oesophagectomy are associated with high morbidity and mortality. Therefore, the identification of preoperative, modifiable risk factors is desirable. The aim of this study was to generate a risk scoring model for AL and CN after oesophagectomy. METHODS: Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018-December 2018. Definitions for AL and CN were those set out by the Oesophageal Complications Consensus Group. Univariate and multivariate analyses were performed to identify risk factors for both AL and CN. A risk score was then produced for both AL and CN using the derivation set, then internally validated using the validation set. RESULTS: This study included 2247 oesophagectomies across 137 hospitals in 41 countries. The AL rate was 14.2% and CN rate was 2.7%. Preoperative factors that were independent predictors of AL were cardiovascular comorbidity and chronic obstructive pulmonary disease. The risk scoring model showed insufficient predictive ability in internal validation (area under the receiver-operating-characteristic curve [AUROC] = 0.618). Preoperative factors that were independent predictors of CN were: body mass index, Eastern Cooperative Oncology Group performance status, previous myocardial infarction and smoking history. These were converted into a risk-scoring model and internally validated using the validation set with an AUROC of 0.775. CONCLUSION: Despite a large dataset, AL proves difficult to predict using preoperative factors. The risk-scoring model for CN provides an internally validated tool to estimate a patient's risk preoperatively.

Predictors of textbook outcome following oesophagogastric cancer surgery.

Textbook outcome (TO) is a composite measure representing an ideal perioperative course, which has been utilized to assess the quality of care in oesophagogastric cancer (OGC) surgery. We aim to determine TO rates among OGC patients in a UK tertiary center, investigate predictors of TO attainment, and evaluate the relationship between TO and survival. A retrospective analysis of a prospectively collected departmental database between 2006 and 2021 was conducted. Patients that underwent radical OGC surgery with curative intent were included. TO attainment required margin-negative resection, adequate lymphadenectomy, uncomplicated postoperative course, and no hospital readmission. Predictors of TO were investigated using multivariable logistic regression. The association between TO and survival was evaluated using Kaplan-Meier analysis and Cox regression modeling. In sum, 667 esophageal cancer and 312 gastric cancer patients were included. TO was achieved in 35.1% of esophagectomy patients and 51.3% of gastrectomy patients. Several factors were independently associated with a low likelihood of TO attainment: T3 stage (odds ratio (OR): 0.41, 95% confidence interval (CI) [0.22-0.79], p = 0.008) and T4 stage (OR:0.26, 95% CI [0.08-0.72], p = 0.013) in the esophagectomy cohort and high BMI (OR:0.93, 95% CI [0.88-0.98], p = 0.011) in the gastrectomy cohort. TO attainment was associated with greater overall survival and recurrence-free survival in esophagectomy and gastrectomy cohorts. TO is a relevant quality metric that can be utilized to compare surgical performance between centers and investigate patients at risk of TO failure. Enhancement of preoperative care measures can improve TO rates and, subsequently, long-term survival.

Delayed Surgical Intervention After Chemoradiotherapy in Esophageal Cancer: (DICE) Study.

OBJECTIVE: To determine the impact of delayed surgical intervention following chemoradiotherapy (CRT) on survival from esophageal cancer. BACKGROUND: CRT is a core component of multimodality treatment for locally advanced esophageal cancer. The timing of surgery following CRT may influence the probability of performing an oncological resection and the associated operative morbidity. METHODS: This was an international, multicenter, cohort study, including patients from 17 centers who received CRT followed by surgery between 2010 and 2020. In the main analysis, patients were divided into 4 groups based upon the interval between CRT and surgery (0-50, 51-100, 101-200, and >200 days) to assess the impact upon 90-day mortality and 5-year overall survival. Multivariable logistic and Cox regression provided hazard ratios (HRs) with 95% CIs adjusted for relevant patient, oncological, and pathologic confounding factors. RESULTS: A total of 2867 patients who underwent esophagectomy after CRT were included. After adjustment for relevant confounders, prolonged interval following CRT was associated with an increased 90-day mortality compared with 0 to 50 days (reference): 51 to 100 days (HR=1.54, 95% CI: 1.04-2.29), 101 to 200 days (HR=2.14, 95% CI: 1.37-3.35), and >200 days (HR=3.06, 95% CI: 1.64-5.69). Similarly, a poorer 5-year overall survival was also observed with prolonged interval following CRT compared with 0 to 50 days (reference): 101 to 200 days (HR=1.41, 95% CI: 1.17-1.70), and >200 days (HR=1.64, 95% CI: 1.24-2.17). CONCLUSIONS: Prolonged interval following CRT before esophagectomy is associated with increased 90-day mortality and poorer long-term survival. Further investigation is needed to understand the mechanism that underpins these adverse outcomes observed with a prolonged interval to surgery.

Pathologic Lymph Node Regression After Neoadjuvant Chemotherapy Predicts Recurrence and Survival in Esophageal Adenocarcinoma: A Multicenter Study in the United Kingdom.

PURPOSE: There is limited evidence regarding the prognostic effects of pathologic lymph node (LN) regression after neoadjuvant chemotherapy for esophageal adenocarcinoma, and a definition of LN response is lacking. This study aimed to evaluate how LN regression influences survival after surgery for esophageal adenocarcinoma. METHODS: Multicenter cohort study of patients with esophageal adenocarcinoma treated with neoadjuvant chemotherapy followed by surgical resection at five high-volume centers in the United Kingdom. LNs retrieved at esophagectomy were examined for chemotherapy response and given a LN regression score (LNRS)-LNRS 1, complete response; 2, <10% residual tumor; 3, 10%-50% residual tumor; 4, >50% residual tumor; and 5, no response. Survival analysis was performed using Cox regression adjusting for confounders including primary tumor regression. The discriminatory ability of different LN response classifications to predict survival was evaluated using Akaike information criterion and Harrell C-index. RESULTS: In total, 17,930 LNs from 763 patients were examined. LN response classified as complete LN response (LNRS 1 ≥1 LN, no residual tumor in any LN; n = 62, 8.1%), partial LN response (LNRS 1-3 ≥1 LN, residual tumor ≥1 LN; n = 155, 20.3%), poor/no LN response (LNRS 4-5; n = 303, 39.7%), or LN negative (no tumor/regression; n = 243, 31.8%) demonstrated superior discriminatory ability. Mortality was reduced in patients with complete LN response (hazard ratio [HR], 0.35; 95% CI, 0.22 to 0.56), partial LN response (HR, 0.72; 95% CI, 0.57 to 0.93) or negative LNs (HR, 0.32; 95% CI, 0.25 to 0.42) compared with those with poor/no LN response. Primary tumor regression and LN regression were discordant in 165 patients (21.9%). CONCLUSION: Pathologic LN regression after neoadjuvant chemotherapy was a strong prognostic factor and provides important information beyond pathologic TNM staging and primary tumor regression grading. LN regression should be included as standard in the pathologic reporting of esophagectomy specimens.

Treatment of anastomotic leak after oesophagectomy for oesophageal cancer: large, collaborative, observational TENTACLE cohort study.

BACKGROUND: Anastomotic leak is a severe complication after oesophagectomy. Anastomotic leak has diverse clinical manifestations and the optimal treatment strategy is unknown. The aim of this study was to assess the efficacy of treatment strategies for different manifestations of anastomotic leak after oesophagectomy. METHODS: A retrospective cohort study was performed in 71 centres worldwide and included patients with anastomotic leak after oesophagectomy (2011-2019). Different primary treatment strategies were compared for three different anastomotic leak manifestations: interventional versus supportive-only treatment for local manifestations (that is no intrathoracic collections; well perfused conduit); drainage and defect closure versus drainage only for intrathoracic manifestations; and oesophageal diversion versus continuity-preserving treatment for conduit ischaemia/necrosis. The primary outcome was 90-day mortality. Propensity score matching was performed to adjust for confounders. RESULTS: Of 1508 patients with anastomotic leak, 28.2 per cent (425 patients) had local manifestations, 36.3 per cent (548 patients) had intrathoracic manifestations, 9.6 per cent (145 patients) had conduit ischaemia/necrosis, 17.5 per cent (264 patients) were allocated after multiple imputation, and 8.4 per cent (126 patients) were excluded. After propensity score matching, no statistically significant differences in 90-day mortality were found regarding interventional versus supportive-only treatment for local manifestations (risk difference 3.2 per cent, 95 per cent c.i. -1.8 to 8.2 per cent), drainage and defect closure versus drainage only for intrathoracic manifestations (risk difference 5.8 per cent, 95 per cent c.i. -1.2 to 12.8 per cent), and oesophageal diversion versus continuity-preserving treatment for conduit ischaemia/necrosis (risk difference 0.1 per cent, 95 per cent c.i. -21.4 to 1.6 per cent). In general, less morbidity was found after less extensive primary treatment strategies. CONCLUSION: Less extensive primary treatment of anastomotic leak was associated with less morbidity. A less extensive primary treatment approach may potentially be considered for anastomotic leak. Future studies are needed to confirm current findings and guide optimal treatment of anastomotic leak after oesophagectomy.

Effect of Anastomotic Leak on Long-Term Survival After Esophagectomy: Multivariate Meta-analysis and Restricted Mean Survival Times Examination.

BACKGROUND: Anastomotic leak (AL) is a serious complication after esophagectomy. It is associated with prolonged hospital stay, increased costs, and increased risk for 90-day mortality. Controversy exists concerning the impact of AL on survival. This study was designed to investigate the effect of AL on long-term survival after esophagectomy for esophageal cancer. METHODS: PubMed, MEDLINE, Scopus, and Web of Science were searched through October 30, 2022. The included studies evaluated the effect of AL on long-term survival. Primary outcome was long-term overall survival. Restricted mean survival time difference (RMSTD), hazard ratio (HR), and 95% confidence intervals (CI) were used as pooled effect size measures. RESULTS: Thirteen studies (7118 patients) were included. Overall, 727 (10.2%) patients experienced AL. The RMSTD analysis shows that at 12, 24, 36, 48, and 60 months, patients not experiencing AL live an average of 0.7 (95% CI 0.2-1.2; p < 0.001), 1.9 (95% CI 1.1-2.6; p < 0.001), 2.6 (95% CI 1.6-3.7; p < 0.001), 3.4 (95% CI 1.9-4.9; p < 0.001), and 4.2 (95% CI 2.1-6.4; p < 0.001) months longer compared with those with AL, respectively. The time-dependent HRs analysis for AL versus no AL shows a higher mortality hazard in patients with AL at 3 (HR 1.94, 95% CI 1.54-2.34), 6 (HR 1.56, 95% CI 1.39-1.75), 12 (HR 1.47, 95% CI 1.24-1.54), and 24 months (HR 1.19, 95% CI 1.02-1.31). CONCLUSIONS: This study seems to suggest a modest clinical impact of AL on long-term OS after esophagectomy. Patients who experience AL seem to have a higher mortality hazard during the first 2 years of follow-up.

Research protocol for the Paraesophageal hernia symptom tool, a prospective multi-center cohort study to identify the need and threshold for surgery and assess the symptom response to surgery.

Large hiatus hernias with a significant paraesophageal component (types II-IV) have a range of insidious symptoms. Management of symptomatic hernias includes conservative treatment or surgery. Currently, there is no paraesophageal hernia disease-specific symptom questionnaire. As a result, many clinicians rely on the health-related quality of life questionnaires designed for gastro-esophageal reflux disease (GORD) to assess patients with hiatal hernias pre- and postoperatively. In view of this, a paraesophageal hernia symptom tool (POST) was designed. This POST questionnaire now requires validation and assessment of clinical utility. Twenty-one international sites will recruit patients with paraesophageal hernias to complete a series of questionnaires over a five-year period. There will be two cohorts of patients-patients with paraesophageal hernias undergoing surgery and patients managed conservatively. Patients are required to complete a validated GORD-HRQL, POST questionnaire, and satisfaction questionnaire preoperatively. Surgical cohorts will also complete questionnaires postoperatively at 4-6 weeks, 6 months, 12 months, and then annually for a total of 5 years. Conservatively managed patients will repeat questionnaires at 1 year. The first set of results will be released after 1 year with complete data published after a 5-year follow-up. The main results of the study will be patient's acceptance of the POST tool, clinical utility of the tool, assessment of the threshold for surgery, and patient symptom response to surgery. The study will validate the POST questionnaire and identify the relevance of the questionnaire in routine management of paraesophageal hernias.

Multicenter, Prospective Cohort Study of Oesophageal Injuries and Related Clinical Outcomes (MUSOIC study).

OBJECTIVE: To identify prognostic factors associated with 90-day mortality in patients with oesophageal perforation (OP), and characterize the specific timeline from presentation to intervention, and its relation to mortality. BACKGROUND: OP is a rare gastro-intestinal surgical emergency with a high mortality rate. However, there is no updated evidence on its outcomes in the context of centralized esophago-gastric services; updated consensus guidelines; and novel non-surgical treatment strategies. METHODS: A multi-center, prospective cohort study involving eight high-volume esophago-gastric centers (January 2016 to December 2020) was undertaken. The primary outcome measure was 90-day mortality. Secondary measures included length of hospital and ICU stay, and complications requiring re-intervention or re-admission. Mortality model training was performed using random forest, support-vector machines, and logistic regression with and without elastic net regularisation. Chronological analysis was performed by examining each patient's journey timepoint with reference to symptom onset. RESULTS: The mortality rate for 369 patients included was 18.9%. Patients treated conservatively, endoscopically, surgically, or combined approaches had mortality rates of 24.1%, 23.7%, 8.7%, and 18.2%, respectively. The predictive variables for mortality were Charlson comorbidity index, haemoglobin count, leucocyte count, creatinine levels, cause of perforation, presence of cancer, hospital transfer, CT findings, whether a contrast swallow was performed, and intervention type. Stepwise interval model showed that time to diagnosis was the most significant contributor to mortality. CONCLUSIONS: Non-surgical strategies have better outcomes and may be preferred in selected cohorts to manage perforations. Outcomes can be significantly improved through better risk-stratification based on afore-mentioned modifiable risk factors.

Predicting long-term risk of reoperations following abdominal and pelvic surgery: a nationwide retrospective cohort study.

BACKGROUND: The risk of reoperations after abdominal and pelvic surgery is multifactorial and difficult to predict. The risk of reoperation is frequently underestimated by surgeons as most reoperations are not related to the initial procedure and diagnosis. During reoperation, adhesiolysis is often required, and patients have an increased risk of complications. Therefore, the aim of this study was to provide an evidence-based prediction model based on the risk of reoperation. MATERIALS AND METHODS: A nationwide cohort study was conducted including all patients undergoing an initial abdominal or pelvic operation between 1 June 2009 and 30 June 2011 in Scotland. Nomograms based on multivariable prediction models were constructed for the 2-year and 5-year overall risk of reoperation and risk of reoperation in the same surgical area. Internal cross-validation was applied to evaluate reliability. RESULTS: Of the 72 270 patients with an initial abdominal or pelvic surgery, 10 467 (14.5%) underwent reoperation within 5 years postoperatively. Mesh placement, colorectal surgery, diagnosis of inflammatory bowel disease, previous radiotherapy, younger age, open surgical approach, malignancy, and female sex increased the risk of reoperation in all the prediction models. Intra-abdominal infection was also a risk factor for the risk of reoperation overall. The accuracy of the prediction model of risk of reoperation overall and risk for the same area was good for both parameters ( c -statistic=0.72 and 0.72). CONCLUSIONS: Risk factors for abdominal reoperation were identified and prediction models displayed as nomograms were constructed to predict the risk of reoperation in the individual patient. The prediction models were robust in internal cross-validation.

Practice variation in anastomotic leak after esophagectomy: Unravelling differences in failure to rescue.

INTRODUCTION: Failure to rescue (FTR) is an important outcome measure after esophagectomy and reflects mortality after postoperative complications. Differences in FTR have been associated with hospital resection volume. However, insight into how centers manage complications and achieve their outcomes is lacking. Anastomotic leak (AL) is a main contributor to FTR. This study aimed to assess differences in FTR after AL between centers, and to identify factors that explain these differences. METHODS: TENTACLE - Esophagus is a multicenter, retrospective cohort study, which included 1509 patients with AL after esophagectomy. Differences in FTR were assessed between low-volume (<20 resections), middle-volume (20-60 resections) and high-volume centers (≥60 resections). Mediation analysis was performed using logistic regression, including possible mediators for FTR: case-mix, hospital resources, leak severity and treatment. RESULTS: FTR after AL was 11.7%. After adjustment for confounders, FTR was lower in high-volume vs. low-volume (OR 0.44, 95%CI 0.2-0.8), but not versus middle-volume centers (OR 0.67, 95%CI 0.5-1.0). After mediation analysis, differences in FTR were found to be explained by lower leak severity, lower secondary ICU readmission rate and higher availability of therapeutic modalities in high-volume centers. No statistically significant direct effect of hospital volume was found: high-volume vs. low-volume 0.86 (95%CI 0.4-1.7), high-volume vs. middle-volume OR 0.86 (95%CI 0.5-1.4). CONCLUSION: Lower FTR in high-volume compared with low-volume centers was explained by lower leak severity, less secondary ICU readmissions and higher availability of therapeutic modalities. To reduce FTR after AL, future studies should investigate effective strategies to reduce leak severity and prevent secondary ICU readmission.

Predicting mortality in patients with anastomotic leak after esophagectomy: development of a prediction model using data from the TENTACLE-Esophagus study.

Anastomotic leak (AL) is a common but severe complication after esophagectomy, and over 10% of patients with AL suffer mortality. Different prognostic factors in patients with AL are known, but a tool to predict mortality after AL is lacking. This study aimed to develop a prediction model for postoperative mortality in patients with AL after esophagectomy. TENTACLE-Esophagus is an international retrospective cohort study, which included 1509 patients with AL after esophagectomy. The primary outcome was 90-day postoperative mortality. Previously identified prognostic factors for mortality were selected as predictors: patient-related (e.g. comorbidity, performance status) and leak-related predictors (e.g. leucocyte count, overall gastric conduit condition). The prediction model was developed using multivariable logistic regression and validated internally using bootstrapping. Among the 1509 patients with AL, 90-day mortality was 11.7%. Sixteen predictors were included in the prediction model. The model showed good performance after internal validation: the c-index was 0.79 (95% confidence interval 0.75-0.83). Predictions for mortality by the internally validated model aligned well with observed 90-day mortality rates. The prediction model was incorporated in an online tool for individual use and can be found at: https://www.tentaclestudy.com/prediction-model. The developed prediction model combines patient-related and leak-related factors to accurately predict postoperative mortality in patients with AL after esophagectomy. The model is useful for clinicians during counselling of patients and their families and may aid identification of high-risk patients at diagnosis of AL. In the future, the tool may guide clinical decision-making; however, external validation of the tool is warranted.