Diagnostic Accuracy Of Screening Tests Research Articles

Clinical and biochemical data for the diagnosis of endogenous hypercortisolism: the "Cushingomic" approach.

The clinical presentation of Cushing's syndrome (CS) overlaps with common conditions. Recommended screening tests are serum cortisol after 1-mg overnight dexamethasone suppression test (DST), urinary free cortisol (UFC), and late-night salivary cortisol (LNSC). We analyzed the diagnostic accuracy of screening tests in 615 patients without CS (263 suspected CS, 319 adrenal and 33 pituitary incidentaloma) and 40 with CS. Principal component analysis, K-means clustering, and neural network were used to compute an integrated analysis among tests, comorbidities, and signs/symptoms of hypercortisolism. The diagnostic accuracy of screening tests for CS was high, DST and UFC were slightly superior to LNSC. The threshold of DST should be adapted to the population considered, especially in adrenal incidentaloma with mild autonomous cortisol secretion: the cutoff to differentiate CS should be increased to 196 nmol/L. Diabetes, hypertension, and obesity were more common in patients without CS: the direction of their vectors was not aligned and their correlation with screening tests was poor. Clustering allowed us to differentiate those patients without CS in cluster one (aged osteoporotic patients with impaired screening tests), cluster two (hypertensive and metabolic phenotype), and cluster three (young subjects with a low likelihood of overt CS). A neural network model that combined screening tests and clinical presentation was able to predict the CS diagnosis in the validation cohort with 99% precision and 86% accuracy. Despite the high diagnostic accuracy of screening tests to detect CS, cortisol-related comorbidities or adrenal incidentaloma should be considered when interpreting a positive test.

Diagnostic accuracy of screening tests for patients suspected of COVID-19, a retrospective cohort study

Background The diagnostic gold standard for Coronavirus-2019 disease (CoViD-19) is reverse transcriptase-polymerase chain reaction (RT-PCR). However, its sensitivity might be suboptimal. The current study aims to investigate predictive factors for false-negative nasopharyngeal RT-PCR in CoViD-19 patients. Additionally, the specificity and sensitivity of RT-PCR on the nasopharyngeal swab, serology and chest computerized-tomography (CCT) as a screening tool for the diagnosis of CoViD-19 were investigated. Methods Medical records of patients admitted at the university hospital UZ Brussel during the CoViD-19 epidemic were reviewed. A group of CoViD-19 patients with false-negative RT-PCR was identified through scrupulous examination of medical records. Serological testing was performed through chemiluminescent microparticle assay. Results Eighteen CoViD-19 patients with ‘false negative’ RT-PCR were identified and compared to 51 ‘true positives’. Logistic regression for prediction of ‘false negative’ RT-PCR found significantly higher serology results at hospitalization and more intensive care unit admission in the group with false-negative testing. In a cohort of 228 patients, the sensitivity of RT-PCR for the diagnosis of CoViD-19 was 85%. The sensitivity of serology was 86% and its specificity 92%. Chest computerized-tomography (CCT) showed a sensitivity of 93%, its specificity was 62%. By combining RT-PCR and serology results any ‘false negative’ could be excluded. Conclusions In this cohort, the sensitivity and specificity of RT-PCR and serology for the diagnosis of CoViD-19 were high and comparable. CCT had the highest sensitivity and confirmed its efficacy as a screening tool. CoViD-19 patients, who have a more severe presentation, might have negative RT-PCR and positive serology results.

Cushing Syndrome

Cushing syndrome is a condition with protean manifestations that are caused by chronic exposure to excess glucocorticoids. Treatment with supraphysiologic doses of glucocorticoids is the most common cause. Pathologic hypercortisolism may result from autonomous adrenal production or as a result of the action of excessive adrenocorticotropic hormone (ACTH) production by a tumor, which stimulates adrenal cortisol production. Primary adrenal forms include unilateral adenoma or carcinoma or, rarely, bilateral hyperplasia and/or nodules. This chapter covers the epidemiology, etiology, pathophysiology, and diagnosis of Cushing syndrome. Clinical manifestations, physical examination findings, and laboratory tests, including tests of the blood and other body fluids, imaging studies, and biopsy, are discussed. The differential diagnosis, treatment options, complications, and prognosis are described. Tables outline clinical features and causes of Cushing syndrome, abnormalities associated with primary adrenal causes of Cushing syndrome, diagnostic accuracy of screening tests, endogenous hypercortisolism without Cushing syndrome, and medical therapy for Cushing syndrome. Figures illustrate the causes of Cushing syndrome and a comparison of the hypothalamic-pituitary-adrenal axis in patients with ACTH-dependent Cushing syndrome and those with pseudo–Cushing syndrome. Algorithms show the evaluation of possible Cushing syndrome and evaluation of the causes of Cushing syndrome. Second-line treatments for Cushing syndrome when surgery fails or is not possible are also detailed. This chapter contains 5 figures, 7 tables, 50 references.

Cushing Syndrome

Cushing syndrome is a condition with protean manifestations that are caused by chronic exposure to excess glucocorticoids. Treatment with supraphysiologic doses of glucocorticoids is the most common cause. Pathologic hypercortisolism may result from autonomous adrenal production or as a result of the action of excessive adrenocorticotropic hormone (ACTH) production by a tumor, which stimulates adrenal cortisol production. Primary adrenal forms include unilateral adenoma or carcinoma or, rarely, bilateral hyperplasia and/or nodules. This chapter covers the epidemiology, etiology, pathophysiology, and diagnosis of Cushing syndrome. Clinical manifestations, physical examination findings, and laboratory tests, including tests of the blood and other body fluids, imaging studies, and biopsy, are discussed. The differential diagnosis, treatment options, complications, and prognosis are described. Tables outline clinical features and causes of Cushing syndrome, abnormalities associated with primary adrenal causes of Cushing syndrome, diagnostic accuracy of screening tests, endogenous hypercortisolism without Cushing syndrome, and medical therapy for Cushing syndrome. Figures illustrate the causes of Cushing syndrome and a comparison of the hypothalamic-pituitary-adrenal axis in patients with ACTH-dependent Cushing syndrome and those with pseudo–Cushing syndrome. Algorithms show the evaluation of possible Cushing syndrome and evaluation of the causes of Cushing syndrome. Second-line treatments for Cushing syndrome when surgery fails or is not possible are also detailed. This chapter contains 5 figures, 7 tables, 50 references.

Implementing a Distress Screening Program in a Thoracic Surgery Service

IntroductionThe aim of the present study was to examine the diagnostic accuracy of screening tests in detecting cases requiring psychological intervention among patients referred for thoracic surgery. MethodsEmotional distress was evaluated in 105 patients referred for thoracic surgery by means of a diagnostic psychological interview (criterion variable). The screening ability of the following methods was analyzed: the physician's opinion (Yes/No), Hospital Anxiety and Depression Scale (HADS), single-item interview: “Are you depressed?” (Depression Question, ADEP) (1–5) and the single-item interview: “Are you anxious?” (Anxiety Question, ANXQ) (1–5). ResultsAccording to the clinical interview, 34% of the patients were clinical cases requiring psychological intervention. The total HADS (cut-off point of 10) showed a sensitivity=0.89, specificity=0.75 and AUC=0.883; the ADEP scale (>1) showed a sensitivity=0.79, specificity=0.74 and AUC=0.795; the ANXQ scale (>1) showed a sensitivity=0.78, specificity=0.41 and AUC=0.690; and the physician's opinion showed a sensitivity=0.47 and specificity=0.86. ConclusionsA high percentage of patients referred for thoracic surgery required psychological intervention. The best instrument to identify those patients requiring psychological care, taking a psychological interview as the criterion variable, was the total HADS score. This test is brief, simple and well accepted by patients; it is easy to implement within a thoracic surgery service and has a good diagnostic accuracy.

Implementación de un programa de cribado del malestar emocional en un servicio de cirugía torácica

IntroductionThe aim of the present study was to examine the diagnostic accuracy of screening tests in detecting cases requiring psychological intervention among patients referred for thoracic surgery. MethodsEmotional distress was evaluated in 105 patients referred for thoracic surgery by means of a diagnostic psychological interview (criterion variable). The screening ability of the following methods was analyzed: the physician's opinion (Yes/No), Hospital Anxiety and Depression Scale (HADS), single-item interview: «Are you depressed?» (Depression Question, ADEP) (1-5) and the single-item interview: «Are you anxious?» (Anxiety Question, ANXQ) (1-5). ResultsAccording to the clinical interview, 34% of the patients were clinical cases requiring psychological intervention. The total HADS (cut-off point of 10) showed a sensitivity=0.89, specificity=0.75 and AUC=0.883; the ADEP scale (>1) showed a sensitivity=0.79, specificity=0.74 and AUC=0.795; the ANXQ scale (>1) showed a sensitivity=0.78, specificity=0.41 and AUC=0.690; and the physician's opinion showed a sensitivity=0.47 and specificity=0.86. ConclusionsA high percentage of patients referred for thoracic surgery required psychological intervention. The best instrument to identify those patients requiring psychological care, taking a psychological interview as the criterion variable, was the total HADS score. This test is brief, simple and well accepted by patients; it is easy to implement within a thoracic surgery service and has a good diagnostic accuracy.

Diagnostic Accuracy of Screening Tests and Treatment for Post-Acute Coronary Syndrome Depression: A Systematic Review.

Patients who have had an acute coronary syndrome (ACS) event have an increased risk for depression. To evaluate the diagnostic accuracy of depression screening instruments and to compare safety and effectiveness of depression treatments in adults within 3 months of an ACS event. MEDLINE, EMBASE, PsycINFO, CINAHL, and Cochrane Database of Systematic Reviews from January 2003 to August 2017, and a manual search of citations from key primary and review articles. English-language studies of post-ACS patients that evaluated the diagnostic accuracy of depression screening tools or compared the safety and effectiveness of a broad range of pharmacologic and nonpharmacologic depression treatments. 2 investigators independently screened each article for inclusion; abstracted the data; and rated the quality, applicability, and strength of evidence. Evidence from 6 of the 10 included studies showed that a range of depression screening instruments produces acceptable levels of diagnostic sensitivity, specificity, and negative predictive values (70% to 100%) but low positive predictive values (below 50%). The Beck Depression Inventory-II was the most studied tool. A large study found that a combination of cognitive behavioral therapy (CBT) and antidepressant medication improved depression symptoms, mental health-related function, and overall life satisfaction more than usual care. Few studies, no evaluation of the influence of screening on clinical outcomes, and no studies addressing several clinical interventions of interest. Depression screening instruments produce diagnostic accuracy metrics that are similar in post-ACS patients and other clinical populations. Depression interventions have an uncertain effect on cardiovascular outcomes, but CBT combined with antidepressant medication produces modest improvement in psychosocial outcomes. Agency for Healthcare Research and Quality (PROSPERO: CRD42016047032).

Screening for pre-diabetes and effectiveness of interventions

Pre-diabetes screening and diagnostic criteria varies internationally. This systematic review assessed the diagnostic accuracy of screening tests for pre-diabetes and efficacy of interventions (lifestyle changes or metformin) in preventing onset of type 2 diabetes in people with pre-diabetes.

Binocular sensitivity and specificity of screening tests in cross-sectional diagnostic studies of paired organs.

We introduce new binocular accuracy measures as alternatives to conventional marginal measures that can be used to evaluate screening tests in diagnostic studies involving paired organs (e.g. eyes and ears). Specifically, we consider screening studies based on a cross-sectional design, where both diagnosis and disease status are determined after study enrolment or sampling, yielding paired binocular binary data described via two models, namely, the extended common correlation model and the Gaussian copula probit model. The first relies on the assumption of exchangeability of fellow organs, while the second is more flexible. Binocular versions of sensitivity and specificity are defined, respectively, as the probability of at least one correct positive diagnosis in patients with one or both organs truly diseased and the probability of two correct negative diagnoses for patients with both organs truly un-diseased. Comparisons between the conventional marginal and binocular sensitivities and specificities are illustrated for both models using data from a diabetic retinopathy study. We show that our methodology provides a viable alternative to conventional ways of assessing diagnostic accuracy of screening tests for paired organs. The binocular versions of sensitivity and specificity reflect the way screening tests are conducted in practice, and they overcome the shortcomings of conventional measures. Copyright © 2017 John Wiley & Sons, Ltd.

Efficacy and effectiveness of screen and treat policies in prevention of type 2 diabetes: systematic review and meta-analysis of screening tests and interventions

Objectives To assess diagnostic accuracy of screening tests for pre-diabetes and efficacy of interventions (lifestyle or metformin) in preventing onset of type 2 diabetes in people with pre-diabetes.Design Systematic review...

Diagnostic accuracy of screening tests for COPD: a systematic review and meta-analysis

BackgroundChronic obstructive pulmonary disease (COPD) is widely underdiagnosed. A number of studies have evaluated the accuracy of screening tests for COPD, but their findings have not been formally summarised. We...

Reducing decision errors in the paired comparison of the diagnostic accuracy of screening tests with Gaussian outcomes

BackgroundScientists often use a paired comparison of the areas under the receiver operating characteristic curves to decide which continuous cancer screening test has the best diagnostic accuracy. In the paired design, all participants are screened with both tests. Participants with suspicious results or signs and symptoms of disease receive the reference standard test. The remaining participants are classified as non-cases, even though some may have occult disease. The standard analysis includes all study participants, which can create bias in the estimates of diagnostic accuracy since not all participants receive disease status verification. We propose a weighted maximum likelihood bias correction method to reduce decision errors.MethodsUsing Monte Carlo simulations, we assessed the method’s ability to reduce decision errors across a range of disease prevalences, correlations between screening test scores, rates of interval cases and proportions of participants who received the reference standard test.ResultsThe performance of the method depends on characteristics of the screening tests and the disease and on the percentage of participants who receive the reference standard test. In studies with a large amount of bias in the difference in the full areas under the curves, the bias correction method reduces the Type I error rate and improves power for the correct decision. We demonstrate the method with an application to a hypothetical oral cancer screening study.ConclusionThe bias correction method reduces decision errors for some paired screening trials. In order to determine if bias correction is needed for a specific screening trial, we recommend the investigator conduct a simulation study using our software.

Screening for Primary Hypertension in Children and Adolescents: U.S. Preventive Services Task Force Recommendation Statement*

Update of the 2003 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for high blood pressure in children and adolescents. The USPSTF reviewed the evidence on screening and diagnostic accuracy of screening tests for blood pressure in children and adolescents, the effectiveness and harms of treatment of screen-detected primary childhood hypertension, and the association of hypertension with markers of cardiovascular disease in childhood and adulthood. This recommendation applies to children and adolescents who do not have symptoms of hypertension. The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for primary hypertension in asymptomatic children and adolescents to prevent subsequent cardiovascular disease in childhood or adulthood.

Screening for Primary Hypertension in Children and Adolescents: U.S. Preventive Services Task Force Recommendation Statement

Update of the 2003 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for high blood pressure in children and adolescents. The USPSTF reviewed the evidence on screening and diagnostic accuracy of screening tests for blood pressure in children and adolescents, the effectiveness and harms of treatment of screen-detected primary childhood hypertension, and the association of hypertension with markers of cardiovascular disease in childhood and adulthood. This recommendation applies to children and adolescents who do not have symptoms of hypertension. The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for primary hypertension in asymptomatic children and adolescents to prevent subsequent cardiovascular disease in childhood or adulthood.

Screening for Visual Impairment in Children Ages 1–5 Years: Update for the USPSTF

Screening could identify preschool-aged children with vision problems at a critical period of visual development and lead to treatments that could improve vision. To determine the effectiveness of screening preschool-aged children for impaired visual acuity on health outcomes. We searched Medline from 1950 to July 2009 and the Cochrane Library through the third quarter of 2009, reviewed reference lists, and consulted experts. We selected randomized trials and controlled observational studies on preschool vision screening and treatments, and studies of diagnostic accuracy of screening tests. One investigator abstracted relevant data, and a second investigator checked data abstraction and quality assessments. Direct evidence on the effectiveness of preschool vision screening for improving visual acuity or other clinical outcomes remains limited and does not adequately address whether screening is more effective than no screening. Regarding indirect evidence, a number of screening tests have utility for identification of preschool-aged children with vision problems. Diagnostic accuracy did not clearly differ for children stratified according to age, although testability rates were generally lower in children 1 to 3 years of age. Treatments for amblyopia or unilateral refractive error were associated with mild improvements in visual acuity compared with no treatment. No study has evaluated school performance or other functional outcomes. Although treatments for amblyopia or unilateral refractive error can improve vision in preschool-aged children and screening tests have utility for identifying vision problems, additional studies are needed to better understand the effects of screening compared with no screening.

Hearing screening in newborns: systematic review of accuracy, effectiveness, and effects of interventions after screening

BackgroundThe authors aimed to evaluate the benefits and harms of universal newborn hearing screening programmes in the detection of hearing impairment.ObjectivesIn the absence of randomised trials evaluating whole screening programmes,...

DETERMINATION OF THE DIAGNOSTIC ACCURACY OF SERUM TRYPSINOGEN AS A SCREENING TEST FOR THE EVALUATION OF PANCREAS EXOCRINE INSUFFICIENCY

Background: The diagnosis of early pancreas exocrine insufficiency remains difficult to determine. The validity and clinical efficacy of current serologic and radiologic studies have not been determined from a gold standard. For example, serum trypsinogen is a commonly used serologic marker to screen for pancreatic disease by non-gastroenterologist. The endoscopic pancreatic function test affords clinical investigators a less cumbersome, "non-histologic" gold standard for comparison studies to determine diagnostic accuracy of screening tests. Aim: To determine the accuracy of serum trypsinogen by comparison to the "gold standard" synthetic secretin stimulation test Methods: The Pancreas Clinic database was queried for patients with serum trypsinogen and 1 hour pancreatic function test studies. Serum trypsinogen was measured as trypsin-like immunoreactivity (abnormal: ≤ 40 ng/mL, normal: > 40 ng/ml) Peak duodenal fluid bicarbonate was measured with an autoanlyzer after synthetic secretin stimulation. (abnormal: ≤ 80 meq/L, normal: > 80meq/L). Data analysis: Microsoft Excel statistical software package. Results: A total of 48 patients were identified: 20 males, mean age 46 years. A 2 × 2 table was constructed to determine the validity and clinical efficacy of serum trypsinogen when compared to peak bicarbonate concentration. There were a significant number of false negatives (n = 15) and false positives (n = 6) which greatly effected the validity of the test. Sensitivity and specificity were 53% and 63%, respectively. Furthermore, the clinical efficacy was also poor, with positive and negative predictive values of 74% and 40, respectively.Table 1: 2×2 Table - Trypsinogen versus BicarbonateConclusions: 1) Accuracy of serum trypsinogen for pancreas exocrine insufficiency is poor. 2) Serum trypsinogen should not be used to screen for exocrine pancreas function. Clinical Implication: The endoscopic pancreatic function test can be used by clinical investigators to determine the validity and clinical efficacy of commonly used diagnostic procedures in the evaluation of pancreas exocrine insufficiency.

Screening tests for renal artery stenosis: A case‐series from an Australian tertiary referral centre

Renal artery stenosis is a common, correctable cause of hypertension and renal impairment, with multiple screening tests available to aid diagnosis. Data assessing the accuracy of screening tests are mostly derived from tight 'experimental' protocols and the application of these tests to large-scale clinical practice is not clear. Our aim was to investigate physician preferences and diagnostic accuracy of screening tests for renal artery stenosis when applied to clinical practice in a large, Australian tertiary referral centre. We investigated all renal angiograms performed at our institution between September 2002 and September 2004, as referred by renal physicians. We accessed hospital and physician records of all patients to document demographics, clinical history, screening investigations, source of screening and angiogram results. The series involved 75 consecutive patients who had 79 screening investigations (four patients had two screening tests). The case series showed that 19 (24%) patients did not have any screening investigations prior to angiography. Duplex ultrasonography was the most utilised screening test, being used in 20 (33%) of the remaining 60 screening tests. Computed tomographic angiography (CTA) was used in 19 (32%), magnetic resonance imaging in 13 (22%) and renal scintigraphy was used in four (7%) screening procedures. Magnetic resonance angiography was the most accurate screening test with a positive predictive value of 92%, followed by duplex ultrasonography with 88% and CTA was relatively inaccurate, with a positive predictive value (PPV) of 58% (P = 0.036). Clinical suspicion alone was inaccurate with a PPV of 40%, except in previously treated renal artery stenosis (PPV 89%). Duplex ultrasonography was the most utilised screening investigation amongst the physicians of our referral base. Magnetic resonance angiography and duplex ultrasonography had good positive predictive values, while CTA may not be as reliable as previously reported when applied to a large, non-selective clinical practice.

0727 Influence of socioeducational factors in the diagnostic accuracy of screening tests for dementia

0727 Influence of socioeducational factors in the diagnostic accuracy of screening tests for dementia