Percent Positive Predictive Value Research Articles

Detection of Cerebral Aneurysm in Cerebral Arteries Following Non-Invasive CT Angiogram

Background: Cerebral aneurysm is the basic cause of sub-arachnoid hemorrhage; Computed tomographic angiogram is the non-invasive approach to diagnose aneurysm by reconstructing the image in 3D dimension making it possible to locate the aneurysm and differentiate it from other arteries. Objective: Focus of this study was to investigate the accuracy of CTA to detect the aneurysm, its type, location and size. Material and method: Data of 50 patients was taken retrospectively with cost-benefit approach that undergoes non-invasive CTA through Aquilion 64-slices CT machine under post-processing work station. Results: This retrospective study is taken with 50 patients, with a 38 percent positive predictive value and a 62 percent negative predictive value, multi-slice CT properly revealed substantial aneurysm in 19 of 50 cases. Conclusion: 64-slices CT provides high diagnostic accuracy for detecting the aneurysm in cerebral arteries with a non-invasive angiogram procedure.

Positive Predictive Value of Upper Lip Bite Test in Predicting Difficult Intubation

Objective: To determine the positive predictive value of upper lip bite test in predicting difficult intubation by taking Cormack and Lehane classification as gold standard. Design of the Study: Cross sectional study. Study Settings: This cross-sectional study was conducted at Department of Anesthesiology, Sir Ganga Ram Hospital, Lahore from 04/06/2021 to 03/12/2021. Materials and Methods: This study involved 313 patients of both genders, aged between 18-70 years undergoing general anesthesia on elective lists having positive upper lip bite test (Grade-III). On the basis of Cormack and Lehane Classification, the diagnosis was verified. Results of the ULBT were compared to the Cormack and Lehane grade-III and grade-IV diagnoses. Every patient's written informed permission was obtained. Results: In The mean age of the patients was 43.78±12.32 years. Majority (n=150, 47.9%) of the patients were aged between 36-52 years. There were 198 (63.3%) male and 115 (36.7%) female patients in the study group. Among the procedures, herniorrhaphy (32.9%) and cholecystectomy (26.8%) were the more frequent procedures followed by thyroidectomy (17.6%), tonsillectomy (13.1%) and mastectomy (9.6%). Majority (42.8%) of the patients belonged to ASA Class-I followed by ASA Class-II (29.7%) and ASA Class-III (27.5%). Difficult intubation was confirmed in 232 (74.1%) patients on Cormack and Lehane Classification (as per operational definition). Thus there were 232 true positive patients with 81 false positive patients. With the gold standard Cormack and Lehane Classification, the upper lip bite test yielded a positive predictive value of 74.1 percent in the prediction of difficult intubation. Conclusion: According to the gold standard of Cormack and Lehane Classification, an upper lip bite test (Grade-III) has a 74.1 percent positive predictive value for difficult intubation in patients undergoing general anaesthesia with endotracheal intubation on the elective list. Keywords: Difficult Intubation, Cormack and Lehane Classification, Upper Lip Bite Test

EBST: An Evolutionary Multi-Objective Optimization Based Tool for Discovering Potential Biomarkers in Ovarian Cancer.

Ovarian cancer is the deadliest gynecologic malignancy, mainly due to limitations in early diagnosis. With advances in high-throughput technologies, research interest in identifying novel and customized tumor biomarkers for early detection and diagnosis is rapidly growing. Here we introduce a new tool called EBST to select microRNAs with biomarker potency in ovarian cancer. This tool has pre-processing options and Its core is the use of Modified Multi Objective Imperialist Competitive Algorithm and six objective functions based on the classifier performance/structure evaluation, clustering error and mRMR filter. In this paper, we used the FDR filter in the pre-processing stage and considered five objective functions, four of which relate to the l1-SVM classifier performance and one to the average mRMR ranking. The proposed method has identified 11 microRNAs including hsa-miR-6784-5p, hsa-miR-1228-5p, hsa-miR-8073, hsa-miR-6756-5p, hsa-miR-1307-3p, hsa-miR-4697-5p, hsa-miR-3663-3p, hsa-miR-328-5p, hsa-miR-1228-3p, hsa-miR-6821-5p, hsa-miR-1268a. Data classification by the proposed model showed 100 percent sensitivity, 99.38 percent specificity, 99.69 percent accuracy and 99.39 percent positive predictive value. In comparison with routine state-of-the-art methods, superiority of our method was confirmed. The biological evaluation of selected microRNAs using bioinformatics tools and published articles confirms their role in cancer signaling pathways. The tool and its MATLAB code are freely available at https://github.com/hanif-y.

Identification of Incident Uterine Fibroids Using Electronic Medical Record Data.

Introduction:Uterine fibroids are the most common benign tumors of the uterus and are associated with considerable morbidity. Diagnosis codes have been used to identify fibroid cases, but their accuracy, especially for incident cases, is uncertain.Methods:We performed medical record review on a random sample of 617 women who received a fibroid diagnosis during 2012–2014 to assess diagnostic accuracy for incident fibroids. We developed 2 algorithms aimed at improving incident case-finding using classification and regression tree analysis that incorporated additional electronic health care data on demographics, symptoms, treatment, imaging, health care utilization, comorbidities and medication. Algorithm performance was assessed using medical record as gold standard.Results:Medical record review confirmed 482 fibroid cases as incident, resulting a 78 percent positive predictive value (PPV) for incident cases based on diagnosis codes alone. Incorporating additional electronic data, the first algorithm classified 395 women with a pelvic ultrasound on diagnosis date but none before as incident cases. Of these, 344 were correctly classified, yielding an 87 percent PPV, 71 percent sensitivity, and 62 percent specificity. A second algorithm built on the first algorithm and further classified women based on a fibroid diagnosis code of 218.9 in 2 years after incident diagnosis and lower body mass index; yielded 93 percent PPV, 53 percent sensitivity, and 85 percent specificity.Conclusions:Compared to diagnosis codes alone, our algorithms using fibroid diagnosis codes and additional electronic data improved identification of incident cases with higher PPV, and high sensitivity or specificity to meet different aims of future studies seeking to identify incident fibroids from electronic data.

A computerized algorithm to capture patient's past preeclampsia and eclampsia history from prenatal clinical notes.

Prenatal clinical notes in electronic medical records contain a wealth of information on pregnancy complications and outcomes. Extracting this critical information provides a unique opportunity for risk assessment to identify at-risk patients who may benefit from early monitoring and intervention. We developed and validated a rule-based computerized algorithm called PregHisEx to characterize past obstetrical history (preeclampsia/eclampsia) by mining prenatal clinical notes for women delivered in 2012 within a large healthcare maintenance organization. The algorithm successfully identified cases with past history of preeclampsia/eclampsia: 2984 definite and 479 probable cases at sentence level; 2419 definite and 348 probable cases at note level; and 762 definite and 82 probable cases at pregnancy episode level. Validation conducted on a random sample of 200 notes using PregHisEx yielded 88.0 percent sensitivity, 98.9 percent specificity, 91.7 percent positive predictive value, 98.3 percent negative predictive value, and F-score of 0.90. The high-performing PregHisEx can be applied for other prenatal conditions.

Food Allergy in South Africa.

Whilst food allergy seems to have increased significantly in many developed countries in the past few decades, quality data on the burden of food allergy in many developing countries is scanty. Until recently, South Africa had a dearth of robustly designed food allergy studies. This article summarizes some of the recent research and observations regarding food allergy from the South African setting. South Africa has recently seen two important food allergy prevalence studies in selected and unselected populations. Both show allergy rates in keeping with those in several westernized countries. The major difference between sensitization and allergy rates in these studies emphasizes the vital role of the food challenge in differentiating true food allergy from asymptomatic sensitisation in equivocal cases. Eczema, young age and living in an urban population are important risk factors for food allergy in South Africa. Egg and peanut allergy are the most common food allergies in both selected and unselected populations in South Africa. In peanut allergy, Ara h 2 is the most useful component in differentiating true allergy from tolerance in peanut-sensitized patients. Use of internationally derived 95% positive predictive values for peanut and egg allergy produced many false positives in South African studies. Studies in South Africa show a trend towards more conservative introduction of peanut in eczema patients, which needs to be addressed in the light of recent studies showing a protective effect of earlier introduction of peanut. "Novel" allergies such as galactose-alpha-1,3-galactose allergy, food protein-induced enterocolitis syndrome and eosinophilic oesophagitis are being described with increasing frequency in South Africa. The surprisingly high prevalence of food allergy in South Africa points towards possible involvement of South Africa in the so-called "food allergy epidemic". This has major implications on the planning of health services in the allergy sector. Food challenges will form a vital role in allergy services. Ninety-five percent positive predictive values for peanut and egg allergy may need revision to be more applicable to the local population.

Extracting and analyzing ejection fraction values from electronic echocardiography reports in a large health maintenance organization.

The left ventricular ejection fraction value is an important prognostic indicator of cardiovascular outcomes including morbidity and mortality and is often used clinically to indicate severity of heart disease. However, it is usually reported in free-text echocardiography reports. We developed and validated a computerized algorithm to extract ejection fraction values from echocardiography reports and applied the algorithm to a large volume of unstructured echocardiography reports between 1995 and 2011 in a large health maintenance organization. A total of 621,856 echocardiography reports with a description of ejection fraction values or systolic functions were identified, of which 70 percent contained numeric ejection fraction values and the rest (30%) were text descriptions explicitly indicating the systolic left ventricular function. The 12.1 percent (16.0% for male and 8.4% for female) of these extracted ejection fraction values are <45 percent. Validation conducted based on a random sample of 200 reports yielded 95.0 percent sensitivity and 96.9 percent positive predictive value.

Incorporating the Last Four Digits of Social Security Numbers Substantially Improves Linking Patient Data from De-identified Hospital Claims Databases.

Assess algorithms for linking patients across de-identified databases without compromising confidentiality. Hospital discharges from 11 Mayo Clinic hospitals during January 2008-September 2012 (assessment and validation data). Minnesota death certificates and hospital discharges from 2009 to 2012 for entire state (application data). Cross-sectional assessment of sensitivity and positive predictive value (PPV) for four linking algorithms tested by identifying readmissions and posthospital mortality on the assessment data with application to statewide data. De-identified claims included patient gender, birthdate, and zip code. Assessment records were matched with institutional sources containing unique identifiers and the last four digits of Social Security number (SSNL4). Gender, birthdate, and five-digit zip code identified readmissions with a sensitivity of 98.0 percent and a PPV of 97.7 percent and identified postdischarge mortality with 84.4 percent sensitivity and 98.9 percent PPV. Inclusion of SSNL4 produced nearly perfect identification of readmissions and deaths. When applied statewide, regions bordering states with unavailable hospital discharge data had lower rates. Addition of SSNL4 to administrative data, accompanied by appropriate data use and data release policies, can enable trusted repositories to link data with nearly perfect accuracy without compromising patient confidentiality. States maintaining centralized de-identified databases should add SSNL4 to data specifications.

Skin prick test responses and allergen-specific IgE levels as predictors of peanut, egg, and sesame allergy in infants

Ninety-five percent positive predictive values (PPVs) provide an invaluable tool for clinicians to avoid unnecessary oral food challenges. However, 95% PPVs specific to infants, the age group most likely to present for diagnosis of food allergy, are limited. We sought to develop skin prick test (SPT) and allergen-specific IgE (sIgE) thresholds with 95% PPVs for challenge-confirmed food allergy in a large population-based cohort of 1-year-old infants with challenges undertaken irrespective of SPT wheal size or previous history of ingestion. HealthNuts is a population-based, longitudinal food allergy study with baseline recruitment of 1-year-old infants. Infants were recruited from council-run immunization sessions during which they underwent SPTs to 4 allergens: egg, peanut, sesame, and cow's milk/shrimp. Any infant with a detectable SPT response was invited to undergo oral food challenge and sIgE testing. Five thousand two hundred seventy-six infants participated in the study. Peanut SPT responses of 8 mm or greater (95% CI, 7-9 mm), egg SPT responses of 4 mm or greater (95% CI, 3-5 mm), and sesame SPT responses of 8 mm or greater (95% CI, 5-9 mm) had 95% PPVs for challenge-proved food allergy. Peanut sIgE levels of 34 kUA/L or greater (95% CI, 14-48 kUA/L) and egg sIgE levels of 1.7 kUA/L or greater (95% CI, 1-3 kUA/L) had 95% PPVs for challenge-proved food allergy. Results were robust when stratified on established risk factors for food allergy. Egg SPT responses and sIgE levels were poor predictors of allergy to egg in baked goods. These 95% PPVs, which were generated from a unique dataset, are valuable for the diagnosis of food allergy in young infants and were robust when stratified across a number of different risk factors.

Reliability and Validity of the Substance Abuse Outcomes Module

Reliability and Validity of the Substance Abuse Outcomes Module

Endorectal Ultrasound in the Management of Patients With Malignant Rectal Polyps

This study was designed to determine the efficacy of endorectal ultrasound in the management of patients with malignant rectal polyps removed by snare excision during colonoscopy. A retrospective review of the medical records and endorectal ultrasound images of 63 patients with endoscopically removed rectal polyps containing invasive adenocarcinoma subsequently staged by endorectal ultrasound. Patients underwent surgery or were followed at a single institution. The polyp characteristics and ultrasound images were compared with the presence of residual tumor in the surgical specimen in patients who underwent further surgery or with recurrence in patients who did not. The morphology of the polyps was described in 31 patients (49 percent); they were sessile in 26 (41 percent) and pedunculated in 6 (9 percent). The margins were positive in 22 patients (35 percent), negative in 19 (30 percent), and not specified in 22 (35 percent). Most tumors were well or moderately differentiated; only 3 (5 percent) were poorly differentiated. Thirty-three patients underwent further surgery (3 low anterior resection, and 30 transanal excision); 30 had no further surgery. The accuracy of endorectal ultrasound in assessing the presence of residual cancer in the rectal wall in patients who had surgery was 54 percent, with a 39 percent positive predictive value and 65 percent negative predictive value. Endorectal ultrasound accurately identified metastatic lymph nodes in two of three patients who had radical surgery. Endorectal ultrasound was more useful than polyp morphologic or histologic criteria to determine the presence of residual cancer in the rectal wall. Endorectal ultrasound does not definitely exclude the possibility of residual tumor in the rectal wall or mesenteric nodes of patients who had a malignant polyp snared endoscopically. Consequently, decisions regarding the definitive management of these patients cannot be based exclusively on the endorectal ultrasound images of the polypectomy site.

The progestogen challenge test in postmenopausal women: clinical and morphologic aspects

The clinical aspects and anatomopathological patterns of 150 postmenopausal women were studied using the progestogen challenge test. An endometrial biopsy was obtained and submitted to the progestogen test. A histopathological analysis of the uterine mucosa from women with a positive progestogen test revealed that the endometrium was active in 44 percent of cases and atrophic or inactive in 56 percent. In contrast, among women with a negative response, the endometrium was atrophic in 94 percent of cases and active in 6 percent. Analysis of clinical aspects did not show significant differences between groups in terms of age; age at menarche and at menopause; fasting blood glucose levels; or body mass. However, postmenopausal time was significantly shorter for women with a positive test, with a correlation between postmenopausal time of one to two years and test positivity. The progestogen challenge test for the detection of atrophic endometrium presented 78.57 percent sensitivity, 77.05 percent specificity, 44 percent positive predictive value, and 94 percent negative predictive value. Thus, when negative, the test is highly valuable, indicating the presence of atrophic endometrium in 94 percent of cases. False-negative results occurred in only 6 percent of the subjects, with no case of hyperplasia detected. However, when the response to the test was positive, the endometrium was atrophic in 56 percent of the cases. We suggest that, in order to avoid invasive procedures, the progestogen challenge test be combined with other methods such as transvaginal ultrasonography.

Unplanned Extubation

Study objective To examine the incidence, clinical impact, and predictors of reintubation following unplanned extubation (UE) in ICU patients. Design Retrospective data collection of prospectively identified consecutive cases of UE. Setting The adult Medical, Coronary, Surgical, Cardiac Surgery, and Neuroscience ICUs of a University Medical Center. Patients Eighty-one episodes of UE in 72 adolescent or adult (53±19 years) ICU patients. Measurements and results In 39 (48 percent) of 81 cases, reintubation was performed within 24 h of UE, 33 (85 percent) within the first hour, and 31 (79 percent) as a result of respiratory distress. There were five documented complications of UE and/or reintubation but no deaths. Clinical predictors for reintubation were sought from routinely available demographic, clinical, laboratory, and respiratory factors which had been documented in the medical records for the 24 h period prior to UE. Using univariate analysis followed by stepwise logistic regression in the first 56 cases (model set), the following factors were identified as being associated with reintubation: (1) volume controlled ventilation (synchronous intermittent mandatory ventilation or assist-control ventilation) with rate more than 6/min; (2) most recent arterial pH level prior to UE being 7.45 or more; (3) most recent ratio of PaO 2 to fraction of inspired oxygen prior to UE less than 250 mm Hg; (4) highest heart rate in the 24 h prior to UE greater than 120 beats per minute; (5) presence of 3 or more coexisting medical disorders (of 7 possible); (6) mental status other than alert; and (7) indication for intubation other than “preoperative.” In the model set, the presence of 4 or more of these 7 factors correctly predicted reintubation in 23 of 25 (92 percent positive predictive value) and presence of 3 or fewer factors correctly predicted no reintubation in 26 of 31 cases (83 percent negative predictive value), with outcome of 88 percent of cases being correctly predicted. The model was tested in the next 24 cases (validation set) in which 18 (75 percent) were correctly predicted. Conclusion Unplanned extubation can result in serious complications; however, about half the patients who have UE can be safely observed without immediate reintubation. Selected clinical factors, which are readily available from standard ICU records for the 24-h period prior to UE, may be useful to predict the likelihood of reintubation.

Unplanned Extubation: Clinical Predictors for Reintubation

To examine the incidence, clinical impact, and predictors of reintubation following unplanned extubation (UE) in ICU patients. Retrospective data collection of prospectively identified consecutive cases of UE. The adult Medical, Coronary, Surgical, Cardiac Surgery, and Neuroscience ICUs of a University Medical Center. Eighty-one episodes of UE in 72 adolescent or adult (53 +/- 19 years) ICU patients. In 39 (48 percent) of 81 cases, reintubation was performed within 24 h of UE, 33 (85 percent) within the first hour, and 31 (79 percent) as a result of respiratory distress. There were five documented complications of UE and/or reintubation but no deaths. Clinical predictors for reintubation were sought from routinely available demographic, clinical, laboratory, and respiratory factors which had been documented in the medical records for the 24 h period prior to UE. Using univariate analysis followed by stepwise logistic regression in the first 56 cases (model set), the following factors were identified as being associated with reintubation: (1) volume controlled ventilation (synchronous intermittent mandatory ventilation or assist-control ventilation) with rate more than 6/min; (2) most recent arterial pH level prior to UE being 7.45 or more; (3) most recent ratio of PaO2 to fraction of inspired oxygen prior to UE less than 250 mm Hg; (4) highest heart rate in the 24 h prior to UE greater than 120 beats per minute; (5) presence of 3 or more coexisting medical disorders (of 7 possible); (6) mental status other than alert; and (7) indication for intubation other than "preoperative." In the model set, the presence of 4 or more of these 7 factors correctly predicted reintubation in 23 of 25 (92 percent positive predictive value) and presence of 3 or fewer factors correctly predicted no reintubation in 26 of 31 cases (83 percent negative predictive value), with outcome of 88 percent of cases being correctly predicted. The model was tested in the next 24 cases (validation set) in which 18 (75 percent) were correctly predicted. Unplanned extubation can result in serious complications; however, about half the patients who have UE can be safely observed without immediate reintubation. Selected clinical factors, which are readily available from standard ICU records for the 24-h period prior to UE, may be useful to predict the likelihood of reintubation.

Bronchoalveolar Lavage Cell Populations in the Diagnosis of Sarcoidosis

Between February 1, 1984, and February 1, 1989, fiberoptic bronchoscopy was performed on 2,692 patients, 592 of whom had bronchoalveolar lavage (BAL). One hundred twenty-eight patients with 16 percent or more lymphocytes in BAL fluid (BALF) were selected for further study. The group included 27 patients with sarcoidosis, 28 with nonsarcoidosis interstitial lung disease (ILD), 22 with lung infection (organism isolated), 31 with inflammation (presumed infection, no organism isolated), 14 with neoplasm, and 6 with bronchial hyperreactivity. The percentages of lymphocytes, B lymphocytes, and T lymphocytes, the CD4/CD8 ratio and the percentages of neutrophils and eosinophils were analyzed individually and in combination for discrimination between the sarcoidosis and nonsarcoidosis patients and compared with the diagnostic accuracy of multiple noncaseating granuloma (MNG) on a simultaneous transbronchial biopsy (Tbbx). Neither the percentages of lymphocytes, T lymphocytes, or B lymphocytes discriminated sarcoidosis from nonsarcoidosis patients. Sarcoidosis patients had higher CD4/CD8 ratios, fewer neutrophils, and 1 percent or less eosinophils in the BAL cell populations. An analysis of CD4/CD8 ratios, and percentages of neutrophils and eosinophils individually revealed that a CD4/CD8 ratio of 4:1 or greater had a positive predictive value of 94 percent in distinguishing sarcoidosis from other ILD but a sensitivity of only 59 percent. The positive predictive value of CD4/CD8 ratio of 4:1 or greater fell to 50 percent in separating sarcoidosis from all other diseases. A CD4/CD8 ratio of less than 1:1 has a 100 percent negative predictive value to exclude the diagnosis of sarcoidosis. Finding 1 percent or less neutrophils in BAL had an 80 percent positive predictive value in distinguishing sarcoidosis from nonsarcoidosis ILD and 51 percent for distinguishing sarcoidosis from all other disease groups. The CD4/CD8 ratio and the percentages of neutrophils and eosinophils also were combined and analyzed for the diagnosis of sarcoidosis. Results showed a BALF with a CD4/CD8 ratio of 2:1 or greater, 1 percent or less neutrophils, and 1 percent or less eosinophils has essentially the same specificity and positive predictive value as MNG on Tbbx in distinguishing sarcoidosis from nonsarcoidosis disease. The combination of finding MNG in a Tbbx specimen plus a BALF CD4/CD8 ratio of 4:1 or greater had a 100 percent positive predictive value in separating sarcoidosis from other ILD and an 81 percent value in separating sarcoidosis from all other disease. Finding MNG in a Tbbx specimen plus a BALF with a CD4/CD8 ratio of 2:1 or greater, 1 percent or less neutrophils, and 1 percent or less eosinophils had a 93 percent positive predictive value in distinguishing sarcoidosis from both nonsarcoidosis ILD and all other diseases.