Diagnostic Accuracy

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Assessing the quality of studies on the diagnostic accuracy of tumor markers

Assessing the quality of studies on the diagnostic accuracy of tumor markers

One of the most widely used tools to asses study quality is the QUADAS instrument. However, it has been designed – and thus far is exclusively used - for systematic reviews or metaanalyses [8]. One problem in using the QUADAS tool lies in the distinction between general study quality and reporting quality. Inevitably, the assessment of quality relates strongly to the reporting of results; a well-conducted study will score poorly in a quality assessment tool if the methods and results are not reported in sufficient detail. The intention of the STARD document was to complement quality assessment of diagnostic accuracy studies by providing a tool focusing on quality of reporting [10, 11]. However, this requires the use of a second instrument and, in consequence, additional time.
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Diagnostic accuracy of CD44V6 for osteosarcoma: a meta-analysis

Diagnostic accuracy of CD44V6 for osteosarcoma: a meta-analysis

should prudentially make the conclusion of the associ- ation with CD44V6 and OS for some potential limita- tions. First, because the rarity of primary malignant tumors of the bone, accounting for approximately 0.2 % of all malignancies, the numbers of articles involved in our analysis were relative small, which may weaken the reliability of our results. In future, multicenter trials with larger sample size might need to confirm our results and explore potential factors that may influence diagnostic accuracy. Second, prominent heterogeneity maybe con- taminate our analysis results. The heterogeneity was probably due to the cut-off values, control groups, assay kits and others. Under this condition, we try to weaken their effects by using a random effect model.
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Diagnostic Accuracy of MRI in Primary Cervical Cancer

Diagnostic Accuracy of MRI in Primary Cervical Cancer

Routine MRI equipment has been updated periodically, but no trend towards a better diagnostic accuracy has been found [22], and, in all the papers we reviewed, the authors used standard 1.5 Tesla equipment. Advanced MRI techniques, like ultra-small particles of iron oxide (USPIO) [23], endorectal/phased-array coils [16], con- trast media enhancement [14] and others (endovaginal opacification [15], dynamic MRI imaging, short tau in- version recovery [STIR] sequence [5]) have been used in a limited number of studies but are not addressed by our review. All these techniques might improve diagnostic accuracy of MRI studies. MRI results vary according to the radiologist’s experience [8,22].
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A study of diagnostic accuracy of the Florida Obsessive Compulsive Inventory – Thai Version (FOCI T)

A study of diagnostic accuracy of the Florida Obsessive Compulsive Inventory – Thai Version (FOCI T)

measures for OCD symptoms and severity [6, 7]. Although there are many well-developed self-reported measures of OCD, none of them is able to rapidly assess both symptom enumeration and severity in a simple format just like the FOCI does [6, 7]. The English version of the FOCI [6] was originally developed from the most acceptable measurement tool for symptom severity of OCD—the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS)—and showed excellent psychometric properties in assessing the presence and severity of obsessive- compulsive symptoms. While very good psychometric properties of the FOCI have been shown in earlier studies [6–9], the data on a receiver operating characteristics (ROC) analysis to determine optimal diagnostic cut-off scores to use it as a screening tool for OCD have never been reported although they are needed [10]. Therefore, the present study aimed to assess the diagnostic accuracy of the Thai version of the FOCI by analyzing the ROC curve and cut-off scores, with the hope that the findings would yield support for subsequent uses of this instru- ment as a measure to identify the OCD patients in the Thai community.
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Comparative Analysis of the Diagnostic Accuracy of Cell Block Technique to Conventional Smears in Minimally Invasive Procedures of Pulmonary Lesions

Comparative Analysis of the Diagnostic Accuracy of Cell Block Technique to Conventional Smears in Minimally Invasive Procedures of Pulmonary Lesions

I solemnly declare that this dissertation titled “COMPARATIVE ANALYSIS OF THE DIAGNOSTIC ACCURACY OF CELL BLOCK TECHNIQUE TO CONVENTIONAL SMEARS IN MINIMALLY INVASIVE PROCEDURES OF PULMONARY LESIONS” submitted by me for the degree of M.D, is the record work carried out by me during the period of 2012-2015 under the guidance of Prof. Dr.ARASI RAJESH, Professor of Pathology, Department of Pathology, Tirunelveli Medical College, Tirunelveli. The dissertation is submitted to The Tamilnadu Dr. M.G.R. Medical University, Chennai, towards the partial fulfilment of requirements for the award of M.D. Degree (Branch III) Pathology examination to be held in April 2015.
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The diagnostic accuracy of the mobile phone teledermatoscopy

The diagnostic accuracy of the mobile phone teledermatoscopy

This study was a prospective, open-label, non-randomized controlled clinical study of the diagnostic accuracy of mobile teledermatoscopy. ethical approval was obtained from eskisehir Osmangazi University Clinical research, ethical Committee (september 26, 2012; protocol no., 2012/272) for this study. The study period was from January 2015 to December 2015. The study protocol complied with the ethical guidelines of the Declaration of Helsinki of the World Medical Association.

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Flexible combination of multiple diagnostic biomarkers to improve diagnostic accuracy

Flexible combination of multiple diagnostic biomarkers to improve diagnostic accuracy

Suppose that every subject has m biomarker measure- ments X = ( X (1) , X (2) , . . . , X (m) ) T with a probability density function f (X), where X (j) is a continuous measure- ment of the j-th biomarker. It also has a binary response variable Y ∈ {1, −1} indicating the subject is diseased or not. In literature, researchers from different fields [8, 9, 14] have discussed and explored the validity of com- bining m biomarker measurements into one single score function g (X) as a more powerful diagnostic tool. A sub- ject is diagnosed as diseased if the combined score g (X) is higher than a given cut-point c, and non-diseased oth- erwise. To summarize its diagnostic accuracy, the Youden index is commonly used in practice. With sensitivity and
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Prenatal diagnosis of LUTO: improving diagnostic accuracy

Prenatal diagnosis of LUTO: improving diagnostic accuracy

Conclusions We propose a clinical score that combines five antenatal variables for the prospective diagnosis of congenital LUTO. This score showed good discriminative capacity in predicting LUTO, and better diagnostic accuracy compared with that of the classic ultrasound triad. Future studies to validate these results should be carried out in order to refine antenatal management of LUTO and prevent inappropriate fetal interventions. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.
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Diagnostic accuracy of capnovolumetry for the identification of airway obstruction – results of a diagnostic study in ambulatory care

Diagnostic accuracy of capnovolumetry for the identification of airway obstruction – results of a diagnostic study in ambulatory care

A strength of the study was that we included a large group of patients consecutively within a large private practice of pneumologists. By reason of free access to health care, also regarding specialists, we think that this enabled us to determine the diagnostic accuracy with minor selection of patients under ´real world´ condi- tions. However, not all patients were included into the analysis, due to interventions performed prior to capno- volumetry. As this occurred in only few patients, it ren- ders this selection secondary. As a major strength we consider the requirement that lung function was assessed via both spirometry and bodyplethysmography at about the same time as capnographic measurements.
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The Accuracy of GAP and MGAP Scoring Systems in Predicting Mortality in Trauma; a Diagnostic Accuracy Study

The Accuracy of GAP and MGAP Scoring Systems in Predicting Mortality in Trauma; a Diagnostic Accuracy Study

Methods: This diagnostic accuracy study was conducted amongst 1861 trauma patients admitted to Rajaee Hospital in Shiraz, Iran, during 2017. The data on demographic features were extracted from the patients’ records. Then, trauma scoring systems including injury severity score (ISS), GAP, MGAP, and Glasgow coma scale (GCS) were compared to evaluate their accuracy in predicting mortality. Area under the receiver operating characteristic (ROC) curve was used to evaluate the accuracy of different trauma scoring systems and detect the sensitivity and specificity in order to predict status of discharge after 24 hours.
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Diagnostic accuracy of prostate cancer antigen 3 (PCA3) prior to first prostate biopsy: A systematic review and meta analysis

Diagnostic accuracy of prostate cancer antigen 3 (PCA3) prior to first prostate biopsy: A systematic review and meta analysis

The strengths of this study were the quality with respect to the selection of patients, the index test, and the reference standard because there was a low risk of bias related to these aspects in all the studies. Moreover, the homogeneity of the studies was 100%, including comparison with the studies available in the literature, which report some degree of heterogeneity. The lack of heterogeneity in the present meta-analysis is a positive aspect that favors the conclusions regarding the diagnostic accuracy of PCA3.

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Time to publication among completed diagnostic accuracy studies: associated with reported accuracy estimates

Time to publication among completed diagnostic accuracy studies: associated with reported accuracy estimates

Results: Forty-nine systematic reviews were identified, containing 92 meta-analyses and 924 unique primary studies, of which 756 could be included. Study completion dates were missing for 285 (38 %) of these. Median time from completion to publication in the remaining 471 studies was 24 months (IQR 16 to 35). Primary studies that reported higher estimates of sensitivity (Spearman ’ s rho = − 0.14; p = 0.003), specificity (rho = − 0.17; p < 0.001), and Youden ’ s index (rho = − 0.22; p < 0.001) had significantly shorter times to publication. When comparing time to publication in studies reporting accuracy estimates above versus below the median, the median number of months was 23 versus 25 for sensitivity ( p = 0.046), 22 versus 27 for specificity ( p = 0.001), and 22 versus 27 for Youden ’ s index ( p < 0.001). These differential time lags remained significant in multivariable Cox regression analyses with adjustment for other study characteristics, with hazard ratios of publication of 1.06 (95 % CI 1.02 to 1.11; p = 0.007) for logit-transformed estimates of sensitivity, 1.09 (95 % CI 1.04 to 1.14; p < 0.001) for logit-transformed estimates of specificity, and 1.09 (95 % CI 1.03 to 1.14; p = 0.001) for logit-transformed estimates of Youden ’ s index. Conclusions: Time to publication was significantly shorter for studies reporting higher estimates of diagnostic accuracy compared to those reporting lower estimates. This suggests that searching and analyzing the published literature, rather than all completed studies, can produce a biased view of the performance of medical tests.
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Diagnostic accuracy of spirometry in primary care

Diagnostic accuracy of spirometry in primary care

accurate diagnosis. Nevertheless, spirometry should be used in diagnosing asthma, as the positive predictive value has been comparatively high in general practice. One important limitation was that 22% of the spirometric maneuvers were not performed correctly in general prac- tice. However, with the analysis of the spirometric maneu- vers as part of the WBP investigation in the lung function laboratory, we received accurate diagnostic values of spirometry. Our results revealed that the predictive values of general practice were slightly lower than in the lung function laboratory. In addition to this, it was not possi- ble to include all patients consecutively, as some patients were not willing to travel to the lung function laboratory of the Medical Hospital. This might have led to an overes- timation of the diagnostic accuracy of spirometry [36]. However, that would also emphasize the impossibility of excluding asthma solely with spirometry. Another limita- tion is due to the choice of the cut-off points. Our use of the ratio FEV 1 /VC ≤ 0.70 as is still recommended by GOLD [5] may have led to some overestimation of airway obstruction in older patients [37] and underestimation in younger patients [38]. The ATS/ERS guideline therefore suggests using lower limits of normal, which is statistically defined by the 5 th lower percentile of a reference popula-
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Diagnostic accuracy of cyst fluid amphiregulin in pancreatic cysts

Diagnostic accuracy of cyst fluid amphiregulin in pancreatic cysts

Comparisons between mucinous and non-mucinous cysts and benign mucinous and malignant mucinous cysts were performed. Based on a non-normal distribu- tion of AREG levels by cyst type, the non-parametric Kruskal-Wallis test was used to compare AREG levels between the multiple categories of cysts. The Wilcoxon rank-sum test was used for comparison of 2 cyst types. A receiver operator curve was generated to characterize the accuracy of cyst fluid AREG to diagnose malignant mucinous cysts. When a significant difference was observed, a threshold with highest diagnostic accuracy was used to report the sensitivity and specificity of AREG. Statistical analysis was performed using STATA 11.0 (College Station, TX).
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Defining ranges for certainty ratings of diagnostic accuracy: A GRADE concept paper

Defining ranges for certainty ratings of diagnostic accuracy: A GRADE concept paper

Currently, guideline panels seldom have access to advanced models. As a result, they will inevitably focus on diagnostic accuracy [9 e 11]. Here, we discuss how one can, in these cases, make fully contextualized ratings of sensitivity and specificity, that is, address whether one would make a different decision at either end of the cer- tainty ranges. One can then use models or explicit consid- erations to decide what sensitivity and specificity one would require to recommend a particular test. That is, what levels of sensitivity and specificity would be required to ensure that the desirable health effects will outweigh the undesirable. In some cases, it is also possible to set ranges for sensitivity and specificity by inferring decision thresh- olds from other recommendations and decisions about testing [12].
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Impact of contacting study authors to obtain additional data for systematic reviews: diagnostic accuracy studies for hepatic fibrosis

Impact of contacting study authors to obtain additional data for systematic reviews: diagnostic accuracy studies for hepatic fibrosis

Results: Of the 66 authors, 68% were successfully contacted and 42% provided additional data for 29 out of 77 studies (38%). All authors who provided data at all did so by the third emailed request (ten authors provided data after one request). Authors of more recent studies were more likely to be located and provide data compared to authors of older studies. The effects of requests for additional data on the conclusions regarding the utility of blood tests to identify patients with clinically significant fibrosis or cirrhosis were generally small for ten out of 12 tests. Additional data resulted in reclassification (using median likelihood ratio estimates) from less useful to moderately useful or vice versa for the remaining two blood tests and enabled the calculation of an estimate for a third blood test for which previously the data had been insufficient to do so. We did not identify a clear pattern for the directional impact of additional data on estimates of diagnostic accuracy.
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A systematic review of the diagnostic accuracy of prostate specific antigen

A systematic review of the diagnostic accuracy of prostate specific antigen

tPSA is an inherent part of the prostate cancer diagnosis pathway. This comprises of symptoms, digital rectal examination (DRE), tPSA level and transurethral ultra- sound guided biopsy (TRUS) (Figure 1). Although it is not certain what the diagnostic pathway would be like in the absence of tPSA, it seems likely that virtually all patients with suspicious clinical findings would require biopsy. In the past few years there has been substantial debate regarding the role of tPSA as a diagnostic tool. There is a large quantity of literature available on tPSA and a simple search of the term PSA OR Prostate Specific Antigen in PubMed gives 20,469 hits. Furthermore the introduction of screening in the USA has brought discussion of whether a similar screening programme should be introduced in Europe. At the centre of this debate is the uncertainty of the diagnostic accuracy of the tPSA test. The focus of this review will be the diagnosis of prostate cancer in patients presenting with symptoms. However other forms of PSA testing such as PSA velocity, PSA density and free to total PSA ratios are not assessed. This is a reflection of clinical
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Ultrasound mapping of pelvic endometriosis: does the location and number of lesions affect the diagnostic accuracy? a multicentre diagnostic accuracy study

Ultrasound mapping of pelvic endometriosis: does the location and number of lesions affect the diagnostic accuracy? a multicentre diagnostic accuracy study

Our study could be criticised for not more accurately differentiating between DIE of the rectum and sigmoid or between rectovaginal and vaginal disease. We could also be criticised for including subjective assessments such as ovarian and pouch of Douglas mobility which cannot be recorded with ease. However we diagnosed ovarian and pouch of Douglas disease with greater ac- curacy than other features of endometriosis which indi- cates that subjective assessment is accurate enough to be used in routine practice. Reproducibility of these find- ings however needs to be externally validated before we can reach a consensus about the value of subjective as- sessment for the diagnosis of ovarian and pouch of Douglas adhesions. Scanning for endometriosis is diffi- cult and we believe that the use of palpation is of critical importance to achieve good diagnostic accuracy. Gynae- cologists use palpation routinely as part of pelvic exam- ination and they can incorporate it more easily into ultrasound examination than sonographers or radiolo- gists. For this reason it remains to be seen whether these results can be extrapolated to units with different levels of experience and expertise.
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Hip pathology: the diagnostic accuracy of magnetic resonance imaging

Hip pathology: the diagnostic accuracy of magnetic resonance imaging

Minimal data is available for the diagnosis of liga- mentum teres tears and chondral rim damage. It is also noted that it can be difficult to quantify the degree of damage with conventional imaging [6]. Furthermore, the experience of the radiologist reporting the images can affect the accuracy of diagnosis [7]. It has been shown that musculoskeletal-trained radiologists have better diagnostic accuracy than those without subspecialty training [8].

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Diagnostic accuracy of ultrasonographic features for lymph node metastasis in papillary thyroid microcarcinoma: a single center retrospective study

Diagnostic accuracy of ultrasonographic features for lymph node metastasis in papillary thyroid microcarcinoma: a single center retrospective study

Initial clinical and pathological data were collected by using EpiData Software v3.1 (EpiData Association, Odense, Denmark). All statistical analyses were per- formed by SPSS software, version 13.0 (SPSS, Chicago, IL), and a two-tailed P value of less than 0.05 was considered as statistically significant. Com- parisons of frequency distributions were performed with a χ 2 test. Multivariate logistic regression analysis was performed to determine independent sonographic predictors for lymph node metastasis from the US characteristics that showed statistical significance. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for each US characteristic suspicious for malignancy were calculated. The diagnostic accuracy of predictions of malignancy was calculated with receiver operating characteristic (ROC) analysis.
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