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Negative Predictive (negative + predictive)
Terms modified by Negative Predictive Selected AbstractsTest Characteristics of High-Resolution Ultrasound in the Preoperative Assessment of Margins of Basal Cell and Squamous Cell Carcinoma in Patients Undergoing Mohs Micrographic SurgeryDERMATOLOGIC SURGERY, Issue 1 2009ANOKHI JAMBUSARIA-PAHLAJANI MD BACKGROUND Noninvasive techniques to assess subclinical spread of nonmelanoma skin cancer (NMSC) may improve surgical precision. High-resolution ultrasound has shown promise in evaluating the extent of NMSC. OBJECTIVES To determine the accuracy of high-resolution ultrasound to assess the margins of basal cell (BCC) and squamous cell carcinomas (SCC) before Mohs micrographic surgery (MMS). METHODS We enrolled 100 patients with invasive SCC or BCC. Before the first stage of MMS, a Mohs surgeon delineated the intended surgical margin. Subsequently, a trained ultrasound technologist independently evaluated disease extent using the EPISCAN I-200 to evaluate tumor extent beyond this margin. The accuracy of high-resolution ultrasound was subsequently tested by comparison with pathology from frozen sections. RESULTS The test characteristics of the high-resolution ultrasound were sensitivity=32%, specificity=88%, positive predictive value=47%, and negative predictive value=79%. Subgroup analyses demonstrated better test characteristics for tumors larger than the median (area>1.74 cm2). Qualitative analyses showed that high-resolution ultrasound was less likely to identify extension from tumors with subtle areas of extension, such as small foci of dermal invasion from infiltrative SCC and micronodular BCC. CONCLUSION High-resolution ultrasound requires additional refinements to improve the preoperative determination of tumor extent before surgical treatment of NMSC. [source] Review article: the role of rapid virological response in determining treatment duration for chronic hepatitis CALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 12 2010F. F. POORDAD Aliment Pharmacol Ther,31, 1251,1267 Summary Background, For patients with chronic hepatitis C, attaining rapid virological response (RVR) is highly predictive of attaining SVR. Aim, To consider the predictive value of RVR in terms of SVR and relapse. Methods, Data were collected from published clinical trials to define the predictive value of RVR for SVR and evaluate the proposed continuum linking RVR to relapse. Results, These data support a 24-week regimen among genotype (G)1 patients who attain RVR with positive predictive values (PPVs) of 77.8% and 85.7% in patients with G1 infection treated for 24 and 48 weeks. Conversely, failure to attain RVR among G1 patients should not be viewed as a criterion for extending treatment duration beyond 48 weeks: negative predictive values (NPVs) were 60.9% and 52.7% in G1 patients without RVR treated for 48 and 72 weeks. Among G2/3 patients, RVR has a high PPV; however, the NPV varied with treatment duration indicating that a 24-week treatment regimen is warranted in G2/3 patients who fail to attain RVR. Conclusions, The present analysis confirms RVR as a strong predictor of SVR that can be used to tailor treatment duration, but which also should be appreciated in the context of treatment duration and regimen. [source] Faecal lactoferrin , a novel test to differentiate between the irritable and inflamed bowel?ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 12 2010R. SIDHU Aliment Pharmacol Ther,31, 1365,1370 Summary Background, Distinguishing between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) can be challenging. Aims, To investigate the utility of faecal lactoferrin as a marker of inflammation in patients with IBD, IBS and controls. Methods, Disease activity in IBD patients was assessed using the modified Harvey,Bradshaw Activity Index. Stool samples were analysed using an ELISA assay. Results, We recruited 137 patients with IBS, 126 with ulcerative colitis (UC) and 104 with Crohn's disease (CD), and 98 healthy volunteers. The median ± IQ lactoferrin concentration (,g/g faecal weight) was 0 ± 1.4 for IBS patients, 6.6 ± 42 for UC patients, 4 ± 12.7 for CD patients and 0.5 ± 2 for healthy controls. Lactoferrin levels were significantly higher in IBD patients compared with IBS/healthy controls (P < 0.001). The median lactoferrin concentrations were significantly higher in active UC & CD patients compared with inactive patients (P < 0.001 and P = 0.002 respectively). The sensitivity, specificity, positive and negative predictive values of lactoferrin in distinguishing active IBD from IBS/healthy controls were 67% and 96%, 87% and 86.8% respectively. Conclusions, Lactoferrin is useful to differentiate between IBD and IBS, and can be used as an adjunct to blood parameters to determine IBD patients who have ongoing inflammation. [source] Usefulness of reagent strips for checking cure in spontaneous bacterial peritonitis after short-course treatmentALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2010J. CASTELLOTE Summary Background, The usefulness of reagent strips to check cure of spontaneous bacterial peritonitis have not been evaluated to date. Aim, To assess the usefulness of ascitic fluid analysis by means of reagent strips to check cure after a 5-day antibiotic course. Methods, We prospectively included all cirrhotic patients diagnosed with spontaneous bacterial peritonitis. On day 5, conventional and reagent strip ascitic fluid analyses were performed. Results, Fifty-three episodes of spontaneous bacterial peritonitis in 51 cirrhotic patients were included. Five patients died before the fifth day and in two patients, the control paracentesis yielded no ascitic fluid. In nine out of 46 cases (19.6%), spontaneous bacterial peritonitis had not resolved by day 5. In 32 out of 33 cases in which the ascitic fluid polymorphonuclear count was <250/,L at day five, the reagent strips was negative. The negative predictive value of the reagent strip at fifth day was 97% and the LR, 0.13. Conclusions, Almost 20% of episodes of spontaneous bacterial peritonitis do not resolve with a short-course of antibiotic treatment. In view of the high negative predictive value and low likelihood ratio for a negative test, reagent strips analysis may be an alternative to conventional cytology if a 5-day antibiotic therapy is planned. [source] Small-intestinal bacterial overgrowth in cirrhosis is related to the severity of liver diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 12 2009C. PANDE Summary Background, Small-intestinal bacterial overgrowth (SIBO) is known to be present in patients with cirrhosis, predisposing to various complications. Aim, To determine the frequency of SIBO in cirrhotics and correlate with severity of cirrhosis. Methods, Small-intestinal bacterial overgrowth was determined by glucose,hydrogen breath test (GHBT). A basal breath-hydrogen >20 ppm or a rise by ,12 ppm above baseline following glucose administration was taken as positive test. Prevalence of SIBO in cirrhotics was compared with healthy controls and correlated with severity of cirrhosis. Results, Of the 53 cirrhotics, 26 (49%) had SIBO, compared to one (8%) control (P = 0.010). The prevalence of SIBO increased with severity of cirrhosis (Child,Pugh A 20%, B 52% and C 73%; P = 0.013). On multivariate analysis, SIBO was independently associated with serum bilirubin and ascites. The best cut-off of serum bilirubin was ,2 mg/dL [AUROC 0.77 (95% CI 0.64,0.90)] predicting SIBO with sensitivity 65%, specificity 81%, positive predictive value 77%, negative predictive value 71% and accuracy 74%. Patients having combination of ascites and serum bilirubin ,2 mg/dL had 82% chance, while patients having neither had only 10% chance of having SIBO. Conclusions, Small-intestinal bacterial overgrowth was prevalent in about half of cirrhotics. Its frequency increased with increase in severity of cirrhosis. Ascites and raised serum bilirubin reliably predicted presence of SIBO. [source] Use of serum biomarkers in a diagnostic test for irritable bowel syndromeALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2009A. J. LEMBO Summary Background Currently, no single serum biomarker can reliably differentiate irritable bowel syndrome (IBS) from other functional gastrointestinal disorders or organic diseases of the gastrointestinal tract. Aim To develop and validate a diagnostic test using serum biomarkers to detect IBS. Methods Ten serum biomarkers were selected from a potential panel of 140 for their ability to differentiate IBS from non-IBS disease in blood samples from patients with IBS, other gastrointestinal disorders and healthy volunteers. A predictive modelling tool was developed to assess patterns and relationships among the 10 serum biomarkers that best differentiated IBS patients from healthy controls and patients with non-IBS gastrointestinal disease. This model was tested in a different cohort of patients and healthy controls (n = 516) to determine the predictive accuracy of differentiating IBS from non-IBS. Results The sensitivity and specificity of the 10-biomarker algorithm for differentiating IBS from non-IBS was 50% and 88% respectively. The positive predictive value was 81%, and the negative predictive value was 64% at 50% IBS prevalence in the validation cohort. Overall accuracy was 70%. Conclusions Assessing serum biomarker patterns can differentiate IBS from non-IBS with reasonable sensitivity and specificity. Assessing serum biomarkers in an overall diagnostic strategy may allow earlier diagnosis and treatment for patients with IBS. [source] The accuracy of the FIB-4 index for the diagnosis of mild fibrosis in chronic hepatitis BALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2009V. MALLET Summary Background, The Fib-4 index is a simple and inexpensive biomarker to delineate liver fibrosis in chronic hepatitis C. Aim, To assess the accuracy of the FIB-4 index in chronic hepatitis B. Methods, We compared the FIB-4 index with 138 synchronous liver biopsies and with 372 synchronous FibroTest performed either in France or in an endemic area (Mayotte, an overseas collectivity of France). Results, The FIB-4 index allowed the correct identification of patients with nil-to-moderate fibrosis with an area under the receiving operating characteristic curve of 0.81 (P < 0.001), increasing as a function of the length of the liver biopsy (up to 0.94 for liver biopsies ,20 mm). A cut-off value ,1.45 differentiated moderate fibrosis from severe fibrosis with a negative predictive value of 86%, a sensitivity of 71.1% and a specificity of 73.1%. Beyond 1.45, the FIB-4 index was not informative. The FIB-4 index was more precise than the AST-to-platelet ratio index and correlated with the FibroTest in 89% of the cases (, = 0.27, P < 0.001) to exclude severe fibrosis. Conclusion, The FIB-4 index is a simple, accurate and inexpensive method to exclude significant liver fibrosis in chronic hepatitis B, a major advantage in HBV-endemic developing countries. [source] Evaluation of Naranjo Adverse Drug Reactions Probability Scale in causality assessment of drug-induced liver injuryALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2008M. GARCÍA-CORTÉS Summary Background, Causality assessment in hepatotoxicity is challenging. The current standard liver-specific Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method scale is complex and difficult to implement in daily practice. The Naranjo Adverse Drug Reactions Probability Scale is a simple and widely used nonspecific scale, which has not been specifically evaluated in drug-induced liver injury. Aim, To compare the Naranjo method with the standard liver-specific Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method scale in evaluating the accuracy and reproducibility of Naranjo Adverse Drug Reactions Probability Scale in the diagnosis of hepatotoxicity. Methods, Two hundred and twenty-five cases of suspected hepatotoxicity submitted to a national registry were evaluated by two independent observers and assessed for between-observer and between-scale differences using percentages of agreement and the weighted kappa (,w) test. Results, A total of 249 ratings were generated. Between-observer agreement was 45% with a ,w value of 0.17 for the Naranjo Adverse Drug Reactions Probability Scale, while there was a higher agreement when using the Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method scale (72%, ,w: 0.71). Concordance between the two scales was 24% (,w: 0.15). The Naranjo Adverse Drug Reactions Probability Scale had low sensitivity (54%) and poor negative predictive value (29%) and showed a limited capability to distinguish between adjacent categories of probability. Conclusion, The Naranjo scale lacks validity and reproducibility in the attribution of causality in hepatotoxicity. [source] The validity of viral hepatitis and chronic liver disease diagnoses in Veterans Affairs administrative databasesALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2008J. R. KRAMER Summary Background, The validity of International Classification of Diseases-9 codes for liver disease has not been determined. Aim, To examine the accuracy of International Classification of Diseases-9 codes for cirrhosis with hepatitis C virus or alcoholic liver disease and HIV or hepatitis B virus coinfection with hepatitis C virus in Veterans Affairs data. Methods, We conducted a retrospective study comparing the Veterans Affairs administrative data with abstracted data from the Michael E. DeBakey VA Medical Center's medical records. We calculated the positive predictive value, negative predictive value, per cent agreement and kappa. Results, For cirrhosis codes, the positive predictive value (probability that cirrhosis is present among those with a code) and negative predictive value (probability that cirrhosis is absent among those without a code) were 90% and 87% with 88% agreement and kappa = 0.70. For hepatitis C virus codes, the positive predictive value and negative predictive value were 93% and 92%, yielding 92% agreement and kappa = 0.78. For alcoholic liver disease codes, the positive predictive value and negative predictive value were 71% and 98%, with 89% agreement and kappa = 0.74. All parameters for HIV coinfection with hepatitis C virus were >89%; however, the codes for hepatitis B virus coinfection had a positive predictive value of 43,67%. Conclusion, These diagnostic codes (except hepatitis B virus) in Veterans Affairs administrative data are highly predictive of the presence of these conditions in medical records and can be reliably used for research. [source] High accuracy and cost-effectiveness of a biopsy-avoiding endoscopic approach in diagnosing coeliac diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2006G. CAMMAROTA Summary Background The ,immersion' technique during upper endoscopy allows the visualization of duodenal villi and the detection of total villous atrophy. Aim To evaluate the accuracy of the immersion technique in detecting total villous atrophy in suspected coeliac patients. The accuracy in diagnosing coeliac disease and the potential cost-sparing of a biopsy-avoiding approach, based on selection of individuals with coeliac disease-related antibodies and on endoscopic detection of absence of villi, were also analysed. Methods The immersion technique was performed in 79 patients with positive antibodies and in 105 controls. Duodenal villi were evaluated as present or absent. As reference, results were compared with histology. Diagnostic approaches, including endoscopy with or without biopsy, were designed to investigate patients with coeliac disease-related antibodies and total villous atrophy. A cost-minimization analysis was performed. Results All patients with positive antibodies had coeliac disease. The sensitivity, specificity, positive and negative predictive values of endoscopy to detect total villous atrophy was always 100%. The sensitivity, specificity, positive and negative predictive values of biopsy-avoiding or biopsy-including strategies in diagnosing coeliac disease when villi were absent was always 100%. The biopsy-avoiding strategy was cost-sparing. Conclusions Upper endoscopy is highly accurate in detecting total villous atrophy coeliac patients. A biopsy-avoiding approach is both accurate and cost-sparing to diagnose coeliac disease in subjects with marked duodenal villous atrophy. [source] Determining the negative predictive value of provocation tests with beta-lactamsALLERGY, Issue 3 2010P. Demoly To cite this article: Demoly P, Romano A, Botelho C, Bousquet-Rouanet L, Gaeta F, Silva R, Rumi G, Rodrigues Cernadas J, Bousquet PJ. Determining the negative predictive value of provocation tests with beta-lactams. Allergy 2010; 65: 327,332. Abstract Background:, The beta-lactam allergic work-up is mostly standardized. However, the negative predictive value of drug provocation tests is not yet well established. Method:, A historical-prospective multicentre cohort study was conducted in four centres (one in France, one in Portugal, two in Italy) to assess the negative predictive value of provocation tests with beta-lactams in patients initially tested for a suspicion of drug allergy/hypersensitivity. Patients were contacted at least 6 months after the work-up, between 2003 and 2007. A new allergic work-up was proposed to reacting patients. Results:, Among the 457 patients included, 365 (79.9%) were followed up (159 [79.1%] from France, 153 [82.7%] from Italy and 53 [74.6%] from Portugal). Only 118 (25.8%) were re-exposed to the negatively tested beta-lactam. Nine (7.6%) reported a non-immediate (occurring more than 1 h after drug administration) reaction: five urticaria, three exanthema and one undefined cutaneous reaction. None were severe. Only four accepted a re-challenge, negative in two cases and positive in the two others. The negative predictive value was 94.1% (89.8,98.3) (111 out of 118 patients). Conclusion:, Although the negative predictive value of drug provocation tests may not be 100%, none of the false negative patients experienced a life-threatening reaction. This should reassure doctors who might hesitate to prescribe beta-lactams, even in patients with negative allergic work-ups. [source] EAACI/GA2LEN task force consensus report: the autologous serum skin test in urticariaALLERGY, Issue 9 2009G. N. Konstantinou Injection of autologous serum collected during disease activity from some patients with chronic spontaneous urticaria (CU) into clinically normal skin elicits an immediate weal and flare response. This observation provides a convincing demonstration of a circulating factor or factors that may be relevant to the understanding of the pathogenesis and management of the disease. This test has become known as the autologous serum skin test (ASST) and is now widely practised despite incomplete agreement about its value and meaning, the methodology and the definition of a positive response. It should be regarded as a test for autoreactivity rather than a specific test for autoimmune urticaria. It has only moderate specificity as a marker for functional autoantibodies against IgE or the high affinity IgE receptor (Fc,RI), detected by the basophil histamine release assay, but high negative predictive value for CU patients without them. It is usually negative in other patterns of CU, including those that are physically induced. Positive ASSTs have been reported in some subjects without CU, including those with multiple drug intolerance, patients with respiratory allergy and healthy controls, although the clinical implications of this are uncertain. It is essential that failsafe precautions are taken to ensure that the patient's own serum is used for skin testing and aseptic procedures are followed for sample preparation and handling. CU patients with a positive ASST (ASST+) are more likely to be associated with HLADR4, to have autoimmune thyroid disease, a more prolonged disease course and may be less responsive to H1-antihistamine treatment than those with a negative ASST (ASST,) although more evidence is needed to confirm these observations conclusively. [source] The importance of nasal provocation test in the diagnosis of natural rubber latex allergyALLERGY, Issue 6 2009M. Ünsel Background:, Most studies regarding natural rubber latex (NRL) allergy have concentrated on the prevalance using skin prick test (SPT) and specific IgE assay. The objective of this study is to examine the target organ (skin, nasal mucosa) responses in patients with positive SPT to NRL using the nasal provacation test (NPT) and glove use test (GUT). Methods:, Four thousand four hundred and twenty patients presented to our polyclinic between July 2003 and January 2007 were evaluated. One thousand six hundred and ninety-nine patients had positive SPT to one or more allergens (NRL and other inhaler allergens). Twenty-nine patients with positive SPT to NRL comprised the NRL sensitive group (group 1). Thirty-five randomized patients with positive SPT to an inhaler allergen other than NRL and negative NRL-specific IgE comprised atopic control group (group 2). Thirty healthy individuals who had no allergic diseases and had negative SPT and NRL-specific IgE comprised the healthy control group (group 3). Results:, The lowest NRL allergen concentration leading to NPT positiveness was 0.05 ,g/mL. NPT was negative in groups 2 and 3. NPT was found to have a sensitivity of 96%, specificity of 100%, negative predictive value of 98% and positive predictive value of 100%. GUT was found to have a sensitivity of 81%, specificity of 90%, negative predictive value of 75% and positive predictive value of 93%. Conclusions:, Nasal provocation test was successfully used for the first time in the diagnosis of NRL allergy. NPT is a more sensitive method as compared to GUT. [source] | ||||||||||