Appropriateness guidelines and predictive rules to select patients for upper endoscopy: a nationwide multicenter study

Development and validation of a scoring system to predict esophagogastroduodenoscopy necessity

OBJECTIVE

This study aimed to develop and validate a scoring system for predicting the need for esophagogastroduodenoscopy (EGD) in clinical practice to enhance accuracy and reduce misapplications.

METHODS

From February 2021 to April 2022, outpatients scheduled for EGD at the Department of Gastroenterology in our hospital were recruited. Patients completed the system evaluation by providing clinical symptoms, relevant medical history, and endoscopic findings. Patients were randomly divided into the training and validation cohorts (at 2:1 ratio). The optimal algorithm was selected from five alternatives including a parallel test. Six physicians participated in a human-computer comparative validation. Sensitivity and negative likelihood ratio (-LR) were used as the primary indicators.

RESULTS

Altogether 865 patients were enrolled, with 578 in the training cohort and 287 in the validation cohort. The scoring system comprised 21 variables, including age, 13 typical clinical symptoms, and seven medical history variables. The parallel test was selected as the final algorithm. Positive EGD findings were reported in 54.5% of the training cohort and 62.7% of the validation cohort. The scoring system demonstrated a sensitivity of 79.0% in the training cohort and 83.9% in the validation cohort, with -LR being 0.627 and 0.615, respectively. Compared to physicians, the scoring system exhibited higher sensitivity (84.0% vs 68.7%, P = 0.02) and a lower -LR (1.11 vs 2.41, P = 0.439).

CONCLUSIONS

We developed a scoring system to predict the necessity of EGD using a parallel test algorithm, which was user-friendly and effective, as evidenced by single-center validation.

Appropriateness of Endoscopic Procedures: A Prospective, Multicenter Study

INTRODUCTION

Advances in endoscopy and open-access systems led to an increase in endoscopic procedures. However, overuse of endoscopy has been consistently reported. This study aims to assess the appropriateness of esophagogastroduodenoscopy (EGD) and colonoscopy referral in the private and public setting.

PATIENTS AND METHODS

We conducted a prospective, multicenter study at 2 public and 5 private endoscopy units. Patients scheduled for elective EGD or colonoscopy were enrolled. Clinical data and endoscopy findings were recorded. Appropriateness of endoscopy was defined according to the American Society for Gastrointestinal Endoscopy guidelines (for EGD) and the European Panel on Appropriateness of Gastrointestinal Endoscopy II (for colonoscopy).

RESULTS

Regarding EGD: 215 patients enrolled (43.7% were males) with a mean age of 61.0 ± 15.1 years; 54.0% (n = 116) were in public hospitals. Referral by a gastroenterologist was made for 34.9% (n = 75). Appropriate indications were made for 62.3% (n = 134): 42.4% in private versus 79.3% in public endoscopy units (odds ratio [OR] 5.20; 95% confidence interval [CI] 2.85-9.49; p < 0.01). Rate of appropriate EGD was 74.7% for gastroenterologist referral and 56.1% for other specialties (OR 2.31; 95% CI 1.24-4.28; p < 0.01). Diagnostic yield for relevant findings was 47.9%. No association between indication appropriateness, gastroenterologist referral, and relevant endoscopic findings was found. Regarding colonoscopy: 287 patients enrolled (49.1% were males) with a mean age of 60.4 ± 14.4 years; 48.1% (n = 138) were in public hospitals. Referral by a gastroenterologist was made for 20.6% (n = 59). Appropriate indications were made for 70.0% (n = 201): 53.0% in private vs. 88.4% in public endoscopy units (OR 6.75; 95% CI 3.66-12.47; p < 0.01). Diagnostic yield was 57.1%. Relevant endoscopic diagnosis was associated with indication: 63.2% in the appropriate vs. 43.0% in the nonappropriate indication group (p < 0.05).

DISCUSSION

A significant percentage of endoscopies, mainly in the private setting, were performed without an appropriate indication. This influenced the diagnostic yield. The use of adequate criteria is fundamental for the rational use of an open-access system.

Detection of an Autism EEG Signature From Only Two EEG Channels Through Features Extraction and Advanced Machine Learning Analysis

BACKGROUND AND OBJECTIVE

In 2 previous studies, we have shown the ability of special machine learning systems applied to standard EEG data in distinguishing children with autism spectrum disorder (ASD) from non-ASD children with an overall accuracy rate of 100% and 98.4%, respectively. Since the equipment routinely available in neonatology units employ few derivations, we were curious to check if just 2 derivations were enough to allow good performance in the same cases of the above-mentioned studies.

METHODS

A continuous segment of artifact-free EEG data lasting 1 minute in ASCCI format from C3 and C4 EEG channels present in 2 previous studies, was used for features extraction and subsequent analyses with advanced machine learning systems. A features extraction software package (Python tsfresh) applied to time-series raw data derived 1588 quantitative features. A special hybrid system called TWIST (Training with Input Selection and Testing), coupling an evolutionary algorithm named Gen-D and a backpropagation neural network, was used to subdivide the data set into training and testing sets as well as to select features yielding the maximum amount of information after a first variable selection performed with linear correlation index threshold.

RESULTS

After this intelligent preprocessing, 12 features were extracted from C3-C4 time-series of study 1 and 36 C3-C4 time-series of study 2 representing the EEG signature. Acting on these features the overall accuracy predictive capability of the best artificial neural network acting as a classifier in deciphering autistic cases from typicals (study 1) and other neuropsychiatric disorders (study 2) resulted in 100 % for study 1 and 94.95 % for study 2.

CONCLUSIONS

The results of this study suggest that also a minor part of EEG contains precious information useful to detect autism if treated with advanced computational algorithms. This could allow in the future to use standard EEG from newborns to check if the ASD signature is already present at birth.

Development of machine learning models to predict RT-PCR results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with influenza-like symptoms using only basic clinical data

BACKGROUND

Reverse Transcription-Polymerase Chain Reaction (RT-PCR) for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) diagnosis currently requires quite a long time span. A quicker and more efficient diagnostic tool in emergency departments could improve management during this global crisis. Our main goal was assessing the accuracy of artificial intelligence in predicting the results of RT-PCR for SARS-COV-2, using basic information at hand in all emergency departments.

METHODS

This is a retrospective study carried out between February 22, 2020 and March 16, 2020 in one of the main hospitals in Milan, Italy. We screened for eligibility all patients admitted with influenza-like symptoms tested for SARS-COV-2. Patients under 12 years old and patients in whom the leukocyte formula was not performed in the ED were excluded. Input data through artificial intelligence were made up of a combination of clinical, radiological and routine laboratory data upon hospital admission. Different Machine Learning algorithms available on WEKA data mining software and on Semeion Research Centre depository were trained using both the Training and Testing and the K-fold cross-validation protocol.

RESULTS

Among 199 patients subject to study (median [interquartile range] age 65 [46-78] years; 127 [63.8%] men), 124 [62.3%] resulted positive to SARS-COV-2. The best Machine Learning System reached an accuracy of 91.4% with 94.1% sensitivity and 88.7% specificity.

CONCLUSION

Our study suggests that properly trained artificial intelligence algorithms may be able to predict correct results in RT-PCR for SARS-COV-2, using basic clinical data. If confirmed, on a larger-scale study, this approach could have important clinical and organizational implications.

Pitfalls in the reporting of upper endoscopy features in cirrhotic patients

BACKGROUND

Upper endoscopy is the main tool for the accurate assessment of the risk of bleeding in cirrhotic patients.

AIM

To evaluate the diagnostic accuracy of upper endoscopy, in cirrhotic subjects, during common clinical practice.

METHODS

120 endoscopic reports produced in different hospitals in our region were retrospectively and randomly selected. After a general evaluation, aimed at assessing the description of various endoscopic features, reports were evaluated by four expert endoscopists and four expert hepatologists. Experts were asked to fill in a questionnaire for each single endoscopic procedure, regarding the diagnostic accuracy of the report.

RESULTS

Endoscopic reports lacked descriptions of the size of esophageal varices and red signs in 14% and 29% of cases respectively. Presence (or absence) of gastric varices or portal hypertensive gastropathy were not reported in 62% and 34% of cases respectively. According to expert endoscopists 41% of the reports were incomplete, while, according to hepatologists, reports were incomplete and inadequate for clinical purposes in 36% of cases.

CONCLUSION

Our study clearly evidenced a significant lack of information in reports on upper endoscopy in cirrhotic patients, and supports the prompt adoption of corrective strategies.

Diagnostic yield of upper endoscopy according to appropriateness: A systematic review

BACKGROUND/AIM

Despite some official guidelines are available, a substantial rate of inappropriateness for upper gastrointestinal (UGI) endoscopies has been reported. This study aimed to estimate the inappropriate rate of UGI in different countries, also including the diagnostic yield.

METHODS

A systematic review of studies on UGI endoscopy appropriateness was performed by adopting official guidelines as reference standard. Diagnostic yield of relevant endoscopic findings and cancers was compared between appropriate and inappropriate procedures. The Odd Ratio (OR) values and the Number-Needed-to-Scope (NNS) were calculated.

RESULTS

Data of 23 studies with a total of 53,392 patients were included. UGI indications were overall inappropriate in 21.7% (95% CI = 21.4-22.1) of the patients. The inappropriateness rate significantly (P < 0.0001) decreased from 35.1% in the earlier studies to 22.1%-23% in the more recent ones. A relevant finding was found in 43.3% of appropriate and in 35.1% of inappropriate endoscopies (P < 0.0001; OR: 1.42, 95% CI = 1.36-1.49; NNS = 12). Prevalence of cancers was also higher in appropriate than in inappropriate UGIs (2.98% vs. 0.09%, P < 0.0001; OR = 3.33; NNS = 48). The prevalence of detected cancers significantly (P < 0.004) increased from 1.38% in the earlier studies to 2.11% in the more recent ones, whilst prevalence of other relevant findings remained similar.

CONCLUSIONS

Rate of inappropriate UGI endoscopies is still high. Diagnostic yield of appropriate endoscopies is higher than that of inappropriate procedures, including upper GI cancers. Therefore, implementation of guidelines in clinical practice is urged.

Appropriateness of American Society for Gastrointestinal Endoscopy Guidelines for Upper Gastrointestinal Endoscopy: A Prospective Analytical Study

Introduction

Extensive use of upper gastrointestinal endoscopy (UGE) with the advent of open access centers has resulted in inappropriate endoscopies. Our study aimed to evaluate the appropriateness of American Society for Gastrointestinal Endoscopy (ASGE) guidelines for UGE and to assess the diagnostic yield of endoscopy in a tertiary care center in South India.

Methods

The study was conducted as a prospective analytical study. Indications for endoscopy were classified as “ASGE appropriate” and “ASGE inappropriate”. The significance of association of ASGE guidelines and other categorical variables with endoscopic findings were assessed.

Results

ASGE appropriate indications and inappropriate indications accounted for 85.9% and 14.1% of endoscopies, respectively. The most common appropriate indication was persistent dyspepsia despite adequate proton-pump inhibitor (PPI) therapy (28.1%) and the only inappropriate indication for endoscopy was isolated dyspepsia without adequate PPI therapy (14.1%). The diagnostic yield of endoscopy for appropriate indications was 69.5% and for inappropriate indications was 55.1%, the difference was statistically significant (P= 0.003; OR-1.857). The sensitivity and specificity of ASGE guidelines was 88.5% and 19.5%, respectively.

Conclusion

According to our study, ASGE guidelines may be considered as appropriate guidelines for UGE in our population and these guidelines were followed 85.9% of the times in referring patients for the same. However, the high diagnostic yield even in inappropriate endoscopies indicates the necessity of further studies that might identify other relevant indications for endoscopy, thus avoiding misutilization of resources without missing out on relevant cases.

High-risk symptoms do not predict gastric cancer precursors

BACKGROUND & STUDY AIMS

Gastric intestinal metaplasia (GIM) is the most common precursor of gastric cancer. Our aim is to determine if presenting symptoms predict gastric cancer precursor lesions in a high-risk population.

PATIENT AND METHODS

Consecutive unique patients evaluated by endoscopy for upper gastrointestinal symptoms at the Los Angeles County Hospital between 2010 and 2014 were evaluated. Presenting symptoms were classified as low- or high-risk depending on the procedure indication as coded using the Clinical Outcomes Research Initiative (CORI) system. Endoscopy and histology results were used to classify findings as benign, GIM, high-risk GIM, or malignant. The primary outcome was the proportion of patients with premalignant or malignant gastric findings who had high-risk clinical indications for endoscopy relative to those with benign results.

RESULTS

A total of 3699 patients underwent endoscopy to evaluate upper gastrointestinal symptoms. There were 373 (10.1%) patients with GIM of which 278 had high-risk GIM. One hundred and sixty (4.3%) patients were diagnosed with gastric cancer. High-risk indications for upper endoscopy predicted gastric cancer (OR 1.8 [95% CI 1.3-2.6]) but not GIM (OR 1.0 [0.8-1.3]) or high-risk GIM (OR 0.9 [0.7-1.2]). Hispanic or Asian patients and patients >50 years old were more likely to have GIM, high-risk GIM, and cancer.

CONCLUSIONS

Performance of upper endoscopy for high-risk indications is inadequate to detect GIM and marginal for malignancy. At risk patients should undergo upper endoscopy for both low- and high-risk symptoms. Screening certain populations deserve additional study and may, in fact, be cost-effective.

Appropriateness of Indications of Upper Gastrointestinal Endoscopy and its Association With Positive Finding

INTRODUCTION

Upper Gastrointestinal Endoscopy is a frequently advised investigation for upper abdominal symptoms. Studies have questioned the appropriateness of indications for upper gastrointestinal endoscopy and have shown that inappropriate indications range from 5% to 49%. The unnecessary upper gastrointestinal endoscopy expose patients to the risk. The number of upper gastrointestinal endoscopy is rising in our region and we assume so is the number of unnecessary upper gastrointestinal endoscopy. With an aim to find out the appropriateness of the indications of upper gastrointestinal endoscopy and compare its association with positive findings, we conducted a cross-sectional descriptive study.

METHODS

All patients undergoing diagnostic upper gastrointestinal endoscopy during study period were included in the study. Appropriateness of indications for upper gastrointestinal endoscopy was defined as per American Society for Gastrointestinal Endoscopy criteria as "appropriate" and "inappropriate". Upper gastrointestinal endoscopy findings were classified as "significant" and "insignificant" based on endoscopy findings. The extent of this association between appropriateness of indications and upper gastrointestinal endoscopy findings was expressed as the odds ratio of finding a relevant diagnosis in patients with an ''appropriate'' indication compared with those with an 'inappropriate'' indication.

RESULTS

Seventy-nine patients were included in the study. Fifty- two (65.8%) of the indications were considered appropriate as per American Society for Gastrointestinal Endoscopy guidelines. Thirty-three (63.5%) of the appropriate indications has clinically significant finding as compared to seven (25.9%) of inappropriate indication with an odds ratio of 4.962 (95% CI:1.773 - 13.890, P=0.002) which is statistically significant.

CONCLUSIONS

Appropriate indications have significantly higher rates of clinically significant findings. Use of guidelines may decrease the number of unnecessary procedures.

An improved I-FAST system for the diagnosis of Alzheimer's disease from unprocessed electroencephalograms by using robust invariant features

OBJECTIVE

This paper proposes a new, complex algorithm for the blind classification of the original electroencephalogram (EEG) tracing of each subject, without any preliminary pre-processing. The medical need in this field is to reach an early differential diagnosis between subjects affected by mild cognitive impairment (MCI), early Alzheimer's disease (AD) and the healthy elderly (CTR) using only the recording and the analysis of few minutes of their EEG.

METHODS AND MATERIAL

This study analyzed the EEGs of 272 subjects, recorded at Rome's Neurology Unit of the Policlinico Campus Bio-Medico. The EEG recordings were performed using 19 electrodes, in a 0.3-70Hz bandpass, positioned according to the International 10-20 System. Many powerful learning machines and algorithms have been proposed during the last 20 years to effectively resolve this complex problem, resulting in different and interesting outcomes. Among these algorithms, a new artificial adaptive system, named implicit function as squashing time (I-FAST), is able to diagnose, with high accuracy, a few minutes of the subject's EEG track; whether it manifests an AD, MCI or CTR condition. An updating of this system, carried out by adding a new algorithm, named multi scale ranked organizing maps (MS-ROM), to the I-FAST system, is presented, in order to classify with greater accuracy the unprocessed EEG's of AD, MCI and control subjects.

RESULTS

The proposed system has been measured on three independent pattern recognition tasks from unprocessed EEG tracks of a sample of AD subjects, MCI subjects and CTR: (a) AD compared with CTR; (b) AD compared with MCI; (c) CTR compared with MCI. While the values of accuracy of the previous system in distinguishing between AD and MCI were around 92%, the new proposed system reaches values between 94% and 98%. Similarly, the overall accuracy with best artificial neural networks (ANNs) is 98.25% for the distinguishing between CTR and MCI.

CONCLUSIONS

This new version of I-FAST makes different steps forward: (a) avoidance of pre-processing phase and filtering procedure of EEG data, being the algorithm able to directly process an unprocessed EEG; (b) noise elimination, through the use of a training variant with input selection and testing system, based on naïve Bayes classifier; (c) a more robust classification phase, showing the stability of results on nine well known learning machine algorithms; (d) extraction of spatial invariants of an EEG signal using, in addition to the unsupervised ANN, the principal component analysis and the multi scale entropy, together with the MS-ROM; a more accurate performance in this specific task.

Outcome predictors in autism spectrum disorders preschoolers undergoing treatment as usual: insights from an observational study using artificial neural networks

BACKGROUND

Treatment as usual (TAU) for autism spectrum disorders (ASDs) includes eclectic treatments usually available in the community and school inclusion with an individual support teacher. Artificial neural networks (ANNs) have never been used to study the effects of treatment in ASDs. The Auto Contractive Map (Auto-CM) is a kind of ANN able to discover trends and associations among variables creating a semantic connectivity map. The matrix of connections, visualized through a minimum spanning tree filter, takes into account nonlinear associations among variables and captures connection schemes among clusters. Our aim is to use Auto-CM to recognize variables to discriminate between responders versus no responders at TAU.

METHODS

A total of 56 preschoolers with ASDs were recruited at different sites in Italy. They were evaluated at T0 and after 6 months of treatment (T1). The children were referred to community providers for usual treatments.

RESULTS

At T1, the severity of autism measured through the Autism Diagnostic Observation Schedule decreased in 62% of involved children (Response), whereas it was the same or worse in 37% of the children (No Response). The application of the Semeion ANNs overcomes the 85% of global accuracy (Sine Net almost reaching 90%). Consequently, some of the tested algorithms were able to find a good correlation between some variables and TAU outcome. The semantic connectivity map obtained with the application of the Auto-CM system showed results that clearly indicated that "Response" cases can be visually separated from the "No Response" cases. It was possible to visualize a response area characterized by "Parents Involvement high". The resultant No Response area strongly connected with "Parents Involvement low".

CONCLUSION

The ANN model used in this study seems to be a promising tool for the identification of the variables involved in the positive response to TAU in autism.

Development of clinical decision rules to predict recurrent shock in dengue

INTRODUCTION

Mortality from dengue infection is mostly due to shock. Among dengue patients with shock, approximately 30% have recurrent shock that requires a treatment change. Here, we report development of a clinical rule for use during a patient's first shock episode to predict a recurrent shock episode.

METHODS

The study was conducted in Center for Preventive Medicine in Vinh Long province and the Children's Hospital No. 2 in Ho Chi Minh City, Vietnam. We included 444 dengue patients with shock, 126 of whom had recurrent shock (28%). Univariate and multivariate analyses and a preprocessing method were used to evaluate and select 14 clinical and laboratory signs recorded at shock onset. Five variables (admission day, purpura/ecchymosis, ascites/pleural effusion, blood platelet count and pulse pressure) were finally trained and validated by a 10-fold validation strategy with 10 times of repetition, using a logistic regression model.

RESULTS

The results showed that shorter admission day (fewer days prior to admission), purpura/ecchymosis, ascites/pleural effusion, low platelet count and narrow pulse pressure were independently associated with recurrent shock. Our logistic prediction model was capable of predicting recurrent shock when compared to the null method (P < 0.05) and was not outperformed by other prediction models. Our final scoring rule provided relatively good accuracy (AUC, 0.73; sensitivity and specificity, 68%). Score points derived from the logistic prediction model revealed identical accuracy with AUCs at 0.73. Using a cutoff value greater than -154.5, our simple scoring rule showed a sensitivity of 68.3% and a specificity of 68.2%.

CONCLUSIONS

Our simple clinical rule is not to replace clinical judgment, but to help clinicians predict recurrent shock during a patient's first dengue shock episode.

Application of artificial neural networks to investigate one-carbon metabolism in Alzheimer's disease and healthy matched individuals

Folate metabolism, also known as one-carbon metabolism, is required for several cellular processes including DNA synthesis, repair and methylation. Impairments of this pathway have been often linked to Alzheimer's disease (AD). In addition, increasing evidence from large scale case-control studies, genome-wide association studies, and meta-analyses of the literature suggest that polymorphisms of genes involved in one-carbon metabolism influence the levels of folate, homocysteine and vitamin B12, and might be among AD risk factors. We analyzed a dataset of 30 genetic and biochemical variables (folate, homocysteine, vitamin B12, and 27 genotypes generated by nine common biallelic polymorphisms of genes involved in folate metabolism) obtained from 40 late-onset AD patients and 40 matched controls to assess the predictive capacity of Artificial Neural Networks (ANNs) in distinguish consistently these two different conditions and to identify the variables expressing the maximal amount of relevant information to the condition of being affected by dementia of Alzheimer's type. Moreover, we constructed a semantic connectivity map to offer some insight regarding the complex biological connections among the studied variables and the two conditions (being AD or control). TWIST system, an evolutionary algorithm able to remove redundant and noisy information from complex data sets, selected 16 variables that allowed specialized ANNs to discriminate between AD and control subjects with over 90% accuracy. The semantic connectivity map provided important information on the complex biological connections among one-carbon metabolic variables highlighting those most closely linked to the AD condition.

Appropriateness and diagnostic yield of upper gastrointestinal endoscopy in an open-access endoscopy system

BACKGROUND/AIM

Open access endoscopy (OAE) decreases the waiting time for patients and clinical burden to gastroenterologist; however, the appropriateness of referrals for endoscopy and thus the diagnostic yield of these endoscopies has become an important issue. The aim of this study was to determine the appropriateness of upper gastrointestinal (GI) endoscopy requests in an OAE system.

PATIENTS AND METHODS

A retrospective chart review of all consecutive patients who underwent an upper gastroscopy in the year 2008 was performed and was defined as appropriate or inappropriate according to the American Society for Gastrointestinal Endoscopy (ASGE) guidelines. Endoscopic findings were recorded and classified as positive or negative. Referrals were categorized as being from a gastroenterologist, internist, surgeon, primary care physicians or others, and on an inpatient or out-patient basis.

RESULTS

A total of 505 consecutive patients were included. The mean age was 45.3 (standard deviation 18.1), 259 (51%) of them were males. 31% of the referrals were thought to be inappropriate. Referrals from primary care physicians were inappropriate in 47% of patients while only 19.5% of gastroenterologists referrals were considered inappropriate. Nearly, 37.8% of the out-patient referrals were inappropriate compared to only 7.8% for inpatients. Abnormal findings were found in 78.5% and 78% of patients referred by gastroenterologists and surgeons respectively while in those referred by primary care physicians it was (49.7%). Inpatients referred for endoscopy had abnormal findings in (81.7%) while in out-patients it was (66.6%). The most common appropriate indications in order of frequency were "upper abdominal distress that persisted despite an appropriate trial of therapy "(78.9%),''persistent vomiting of unknown cause "(19.2%), upper GI bleeding or unexplained iron deficiency anemia (7.6%). The sensitivity and specificity of the ASGE guidelines in our study population was 70.3% and 35% respectively.

CONCLUSION

A large proportion of patients referred for endoscopy through our open-access endoscopy unit are considered inappropriate, with significant differences among specialties. These results suggest that if proper education of practitioners was implemented, a better utilization would be expected.

Value of fecal calprotectin in the evaluation of patients with abdominal discomfort: an observational study

Background

The evaluation of patients with abdominal discomfort is challenging and patient selection for endoscopy based on symptoms is not reliable. We evaluated the diagnostic value of fecal calprotectin in patients with abdominal discomfort.

Methods

In an observational study, 575 consecutive patients with abdominal discomfort referred for endoscopy to the Department of Gastroenterology & Hepatology at the University Hospital Basel in Switzerland, were enrolled in the study. Calprotectin was measured in stool samples collected within 24 hours before the investigation using an enzyme-linked immunosorbent assay. The presence of a clinically significant finding in the gastrointestinal tract was the primary endpoint of the study. Final diagnoses were adjudicated blinded to calprotectin values.

Results

Median calprotectin levels were higher in patients with significant findings (N = 212, median 97 μg/g, IQR 43-185) than in patients without (N = 326, 10 μg/g, IQR 10-23, P < 0.001). The area under the receiver operating characteristics curve (AUC) to identify a significant finding was 0.877 (95% CI, 0.85-0.90). Using 50 μg/g as cut off yielded a sensitivity of 73% and a specificity of 93% with good positive and negative likelihood ratios (10.8 and 0.29, respectively). Fecal calprotectin was useful as a diagnostic parameter both for findings in the upper intestinal tract (AUC 0.730, 0.66-0.79) and for the colon (AUC 0.912, 0.88-0.94) with higher diagnostic precision for the latter (P < 0.001). In patients > 50 years, the diagnostic precision remained unchanged (AUC 0.889 vs. 0.832, P = 0.165).

Conclusion

In patients with abdominal discomfort, fecal calprotectin is a useful non-invasive marker to identify clinically significant findings of the gastrointestinal tract, irrespective of age.