The main purpose of the study was to define optimal criterion-referenced cut-points for cardiorespiratory fitness (CRF) associated with overweight/obesity. In this cross-sectional study, participants were 1,612 children aged 7-14 years (mean age ± SD = 9.7 ± 2.4 years; 52.5% girls). CRF was assessed by the Maximal multistage 20-m shuttle run test, from which maximal oxygen uptake (VO2max) was estimated. Anthropometric indices included body-mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Receiver operating characteristic (ROC) curves were performed to determine cut-off points. In boys, the optimal cut-off points of CRF in defining overweight/obesity for BMI, WC, and WHtR were 44.6, 46.4, and 46.9 mlO2/kg/min. The areas under the curves (AUC) were 0.83 (95% CI 0.78-0.88, p < 0.001), 0.77 (95% CI 0.71-0.83, p < 0.001), and 0.90 (95% CI 0.86-0.93, p < 0.001). In girls, the optimal cut-off points were 41.0, 40.8, and 40.7 mlO2/kg/min for BMI, WC, and WHtR, with the AUCs of 0.86 (95% CI 0.82-0.90, p < 0.001), 0.83 (95% CI 0.79-0.88), and 0.88 (95% CI 0.84-0.93, p < 0.001). In conclusion, our newly developed cut-off points for CRF assessed by the Maximal multistage 20-m shuttle run test may adequately detect primary school-aged boys and girls with general and abdominal obesity.
- Publication type
- Journal Article MeSH
There is no general consensus regarding which accelerometer cut-off point (CoP) is most acceptable to estimate the time spent in moderate-to-vigorous physical activity (MVPA) in children and choice of an appropriate CoP primarily remains a subjective decision. Therefore, this study aimed to analyze the influence of CoP selection on the mean MVPA and to define the optimal thresholds of MVPA derived from different accelerometer CoPs to avoid overweight/obesity and adiposity in children aged 7 to 12 years. Three hundred six children participated. Physical activity (PA) was monitored for seven consecutive days using an ActiGraph accelerometer (model GT3X) and the intensity of PA was estimated using the five most frequently published CoPs. Body adiposity was assessed using a multi-frequency bioelectrical impedance analysis. There was found a wide range of mean levels of MVPA that ranged from 27 (Puyau CoP) to 231 min∙d-1 (Freedson 2005 CoP). A receiver operating characteristic curve analysis indicated that the optimal thresholds for counts per minute (cpm) and MVPA derived from the Puyau CoP was the most useful in classifying children according to their body mass index (BMI) and fat mass percentage (FM%). In the total sample, the optimal thresholds of the MVPA derived from the Puyau CoP were 22 and 23 min∙d-1 when the categories based on BMI and FM%, respectively, were used. The children who did not meet these optimal thresholds had a significantly increased risk of being overweight/obese (OR = 2.88, P < 0.01) and risk of having excess fat mass (OR = 2.41, P < 0.01). In conclusion, the decision of selecting among various CoPs significantly influences the optimal levels of MVPA. The Puyau CoP of 3 200 cmp seems to be the most useful for defining the optimal level of PA for pediatric obesity prevention.
- MeSH
- Adiposity MeSH
- Accelerometry MeSH
- Exercise * MeSH
- Child MeSH
- Body Mass Index MeSH
- Humans MeSH
- Pediatric Obesity prevention & control MeSH
- Odds Ratio MeSH
- Area Under Curve MeSH
- ROC Curve MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
AIMS: Physical activity (PA) is an important target for improving clinical outcomes in heart failure (HF) patients. Nonetheless, assessing the daily PA profile in this population is a challenging task, traditionally performed using self-report questionnaires such as the International PA Questionnaire Short Form (IPAQ-SF). This study aimed to evaluate the concurrent validity of the IPAQ-SF and accelerometer-assessed PA using six published cut-points in patients with HF and reduced or mildly reduced ejection fraction. METHODS AND RESULTS: The concordance between the IPAQ-SF and a hip-worn accelerometer regarding daily time spent performing moderate to vigorous PA in bouts of at least 10 min was assessed in 53 participants for seven consecutive days using six different cut-points (Barnett, Dibben, Mark, Sanders, Troiano, and Vaha-Ypya). Spearman's correlation and Bland-Altman plots were used to evaluate concurrent validity between methods. Regressions were used to study the association between patient variables, wear protocol (waking hour or 24 h), and absolute bias. The kappa index was used to evaluate the concordance between IPAQ-SF and accelerometry for classifying patients as active or non-active. All analyses were re-run using non-bouted metrics to investigate the effect of bouted versus non-bouted analysis. The IPAQ-SF and accelerometry showed low to negligible correlation (ρ = 0.12 to 0.37), depending on the cut-point used. The regression analysis showed that the absolute bias was higher in participants following the waking-hour protocol at all cut-points except Dibben's (P ≤ 0.007). The concordance between the two methods to classify patients as active and non-active was low when using Mark (κ = 0.23) and Barnett (κ = 0.34) cut-points and poor for the remaining cut-points (κ = 0.03 to 0.18). The results of the sensitivity analysis showed negligible to low correlation using non-bouted metrics (ρ = 0.27 to 0.33). CONCLUSIONS: Moderate to vigorous PA measures using IPAQ-SF and accelerometers are not equivalent, and we do not encourage researchers to use IPAQ-SF alone when assessing PA in HF patients. Moreover, applying personalized collection and processing criteria is important when assessing PA in HF patients. We recommend following the 24 h protocol and selecting cut-points calibrated in patients with cardiovascular diseases. Finally, it is necessary to develop a new tailored questionnaire that considers walking intensity and is adjusted to the current World Health Organisation recommendations, which use non-bouted metrics.
- MeSH
- Accelerometry MeSH
- Exercise * MeSH
- Humans MeSH
- Surveys and Questionnaires MeSH
- Heart Failure * diagnosis MeSH
- Self Report MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) can be classified into groups A/C or B/D based on symptom intensity. Different threshold values for symptom questionnaires can result in misclassification and, in turn, different treatment recommendations. The primary aim was to find the best fitting cut-points for Global initiative for chronic Obstructive Lung Disease (GOLD) symptom measures, with an modified Medical Research Council dyspnea grade of 2 or higher as point of reference. METHODS: After a computerized search, data from 41 cohorts and whose authors agreed to provide data were pooled. COPD studies were eligible for analyses if they included, at least age, sex, postbronchodilator spirometry, modified Medical Research Council, and COPD Assessment Test (CAT) total scores. MAIN OUTCOMES: Receiver operating characteristic curves and the Youden index were used to determine the best calibration threshold for CAT, COPD Clinical Questionnaire, and St. Georges Respiratory Questionnaire total scores. Following, GOLD A/B/C/D frequencies were calculated based on current cut-points and the newly derived cut-points. FINDINGS: A total of 18,577 patients with COPD [72.0% male; mean age: 66.3 years (standard deviation 9.6)] were analyzed. Most patients had a moderate or severe degree of airflow limitation (GOLD spirometric grade 1, 10.9%; grade 2, 46.6%; grade 3, 32.4%; and grade 4, 10.3%). The best calibration threshold for CAT total score was 18 points, for COPD Clinical Questionnaire total score 1.9 points, and for St. Georges Respiratory Questionnaire total score 46.0 points. CONCLUSIONS: The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on individual disease management. Further validation in prospective studies of these new values are needed.
- MeSH
- Global Health MeSH
- Pulmonary Disease, Chronic Obstructive classification diagnosis therapy MeSH
- Risk Assessment MeSH
- Middle Aged MeSH
- Humans MeSH
- Evidence-Based Medicine MeSH
- Disease Progression * MeSH
- Aged MeSH
- Sex Factors MeSH
- Practice Guidelines as Topic * MeSH
- Severity of Illness Index MeSH
- Sickness Impact Profile MeSH
- Symptom Assessment methods MeSH
- Age Factors MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Objective. The main aim of this study was to verify the sensitivity and specificity of Addenbrooke's Cognitive Examination-Revised (ACE-R) in discriminating between Parkinson's disease (PD) with normal cognition (PD-NC) and PD with mild cognitive impairment (PD-MCI) and between PD-MCI and PD with dementia (PD-D). We also evaluated how ACE-R correlates with neuropsychological cognitive tests in PD. Methods. We examined three age-matched groups of PD patients diagnosed according to the Movement Disorder Society Task Force criteria: PD-NC, PD-MCI, and PD-D. ROC analysis was used to establish specific cut-off scores of ACE-R and its domains. Correlation analyses were performed between ACE-R and its subtests with relevant neuropsychological tests. Results. Statistically significant differences between groups were demonstrated in global ACE-R scores and subscores, except in the language domain. ACE-R cut-off score of 88.5 points discriminated best between PD-MCI and PD-NC (sensitivity 0.68, specificity 0.91); ACE-R of 82.5 points distinguished best between PD-MCI and PD-D (sensitivity 0.70, specificity 0.73). The verbal fluency domain of ACE-R demonstrated the best discrimination between PD-NC and PD-MCI (cut-off score 11.5; sensitivity 0.70, specificity 0.73) while the orientation/attention subscore was best between PD-MCI and PD-D (cut-off score 15.5; sensitivity 0.90, specificity 0.97). ACE-R scores except for ACE-R language correlated with specific cognitive tests of interest.
- Publication type
- Journal Article MeSH
The performance of diagnostic tests in intervention trials of Helicobacter pylori (H.pylori) eradication is crucial, since even minor inaccuracies can have major impact. To determine the cut-off point for 13C-urea breath test (13C-UBT) and to assess if it can be further optimized by serologic testing, mathematic modeling, histopathology and serologic validation were applied. A finite mixture model (FMM) was developed in 21,857 subjects, and an independent validation by modified Giemsa staining was conducted in 300 selected subjects. H.pylori status was determined using recomLine H.pylori assay in 2,113 subjects with a borderline 13C-UBT results. The delta over baseline-value (DOB) of 3.8 was an optimal cut-off point by a FMM in modelling dataset, which was further validated as the most appropriate cut-off point by Giemsa staining (sensitivity = 94.53%, specificity = 92.93%). In the borderline population, 1,468 subjects were determined as H.pylori positive by recomLine (69.5%). A significant correlation between the number of positive H.pylori serum responses and DOB value was found (rs = 0.217, P < 0.001). A mathematical approach such as FMM might be an alternative measure in optimizing the cut-off point for 13C-UBT in community-based studies, and a second method to determine H.pylori status for subjects with borderline value of 13C-UBT was necessary and recommended.
- MeSH
- Algorithms * MeSH
- Breath Tests methods MeSH
- Molecular Diagnostic Techniques standards MeSH
- Adult MeSH
- Helicobacter Infections diagnosis MeSH
- Carbon Isotopes MeSH
- Clinical Trials as Topic MeSH
- Middle Aged MeSH
- Humans MeSH
- Limit of Detection MeSH
- Urea MeSH
- Stomach Neoplasms diagnosis microbiology MeSH
- Models, Theoretical MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Validation Study MeSH
... Introduction 4 -- 1.1 Method comparison 4 -- 1.2 Norm curves 7 -- 1.3 Optimal cut-off points 9 -- 2. ... ... Optimal cut-off points in receiver operating characteristics curve analysis (paper VI) 41 -- 4.1 Purpose ... ... 41 -- 4.2 Methods 41 -- 4.2.1 Simulation set-up -- 41 -- 4.2.2 Optimality criterion for cut-off point ... ... determination -- 43 -- 4.2.3 Convergence behavior of optimal cut-off points with increasing sample size ... ... -- 44 -- 4.2.4 A heuristic and path-based algorithm for cut-off point determination -- 44 -- 4.3 Results ...
iv, 65 stran : ilustrace ; 30 cm
- MeSH
- Biostatistics MeSH
- Evaluation Studies as Topic MeSH
- Reproducibility of Results MeSH
- Statistics as Topic MeSH
- Health Status Indicators MeSH
- Publication type
- Academic Dissertation MeSH
- Conspectus
- Statistika
- NML Fields
- statistika, zdravotnická statistika
INTRODUCTION AND HYPOTHESIS: TVT-O production has been modified to laser cutting from mechanical cutting. We compared the behavior of laser and mechanically cut tension-free vaginal tape-obturator (TVT-O) using ultrasound at various time points after surgery. METHODS: This is a retrospective analysis of clinical and ultrasound data from two previously reported randomized controlled trials with TVT-O. Behavior of mechanically cut TVT-O implanted in January 2007 to November 2009 and laser-cut TVT-O implanted in May 2010 to May 2012 was assessed by ultrasound at day 1, the 2nd week, the 3rd month, and the 1st and 2nd years post-operatively. Bladder neck and tape margins positions were described by coordinates in the orthogonal system calculated from polar coordinates. Tape mobility was measured as a change in the upper and lower tape margin position from rest to maximal Valsalva. Comparison of 2-year subjective and objective surgery outcomes was also performed. RESULTS: In total, 68 mechanically cut and 50 laser-cut TVT-Os were implanted. Follow-up data were available from 49 and 45 women respectively. No differences in any baseline characteristics or bladder neck mobility were observed. Significantly lower tape mobility was observed on day 1 and week 2 after mechanically cut TVT-O, although subsequent mobility was comparable to laser-cut TVT-O. The subjective and objective surgery outcomes were comparable. CONCLUSIONS: Although without clinical significance, early postoperative behavior of the mechanically cut and laser-cut TVT-O tapes differs. The less stiff, mechanically-cut TVT-O loosens within 2 weeks of implantation, whereas the stiffer, laser-cut TVT-O keeps its tension.
- MeSH
- Surgical Tape * MeSH
- Gynecologic Surgical Procedures instrumentation methods MeSH
- Humans MeSH
- Urinary Bladder MeSH
- Postoperative Period MeSH
- Retrospective Studies MeSH
- Urinary Incontinence, Stress surgery MeSH
- Suburethral Slings * MeSH
- Ultrasonography * MeSH
- Urologic Surgical Procedures methods MeSH
- Treatment Outcome MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Ve své práci jsme předložili přehled o ROC (receiver operating characteristic) analýze a jejím použití v medicíně. Článek uvádí krátký přehled teorie i způsob, jak lze ROC křivku vytvořit, a dále zdůrazňuje význam analýzy nákladů a přínosů (Cost-Benefit Analysis) při volbě optimálního dělícího bodu (prahu). Použití ROC analýzy jsme ukázali na několika příkladech v části „Analýza nákladů a přínosů“. Na těchto příkladech vidíme, že pro určení optimálního dělícího bodu má rozhodující význam prevalence onemocnění, závažnost onemocnění, rizika a nežádoucí účinky léčby nebo diagnostického testu, celkové náklady na léčbu pravdivě i falešně pozitivních pacientů i riziko nedostatečné nebo žádné léčby u falešně negativních.
An overview of the use of Receiver Operating Characteristic (ROC) analysis within medicine is provided. A survey of the theory behind the analysis is offered together with a presentation on how to create a ROC curve and how to use Cost – Benefit analysis to determine the optimal cut-off point or threshold. The use of ROC analysis is exemplified in the “Cost – Benefit analysis” section of the paper. In these examples, it can be seen that the determination of the optimal cut-off point is mainly influenced by the prevalence and the severity of the disease, by the risks and adverse events of treatment or the diagnostic testing, by the overall costs of treating true and false positives (TP and FP), and by the risk of deficient or non-treatment of false negative (FN) cases.
Galactomannan antigen (GM) testing has been used for decades to screen immunocompromised patients for invasive aspergillosis (IA). Recent publications suggested that using a higher cut-off value than 0.5 in bronchoalveolar lavage fluid (BALF) could be more discriminant for hematology patients. We retrospectively analyzed the values of GM in BALF over 7 years (from 2010 to 2016). Performance indicators of the GM in BALF, according to three different cut-off values (0.5, 0.8, 1.5), were calculated using Stata 14.1. IA classification for hematology patients was based on European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria, as defined in 2008. A number of 716 GM were performed on BALF from 2010 to 2016 (597 patients) and 66 were positive (> 0.5). Among these 597 patients, 27 IA were diagnosed, 13 with a positive GM in BALF, 9 with a negative GM in BALF, and 5 unclassified IA (ICU patients). The analysis of performance indicators, based on our local data, did not demonstrate any significant difference using a higher cut-off value of GM in BALF. This result may be explained by the local recruitment of patients and by pre-analytic variations during BALF realization.
- MeSH
- Aspergillus MeSH
- Aspergillosis diagnosis metabolism microbiology MeSH
- Biomarkers MeSH
- Bronchoalveolar Lavage Fluid * MeSH
- Immunocompromised Host MeSH
- Humans MeSH
- Mannans metabolism MeSH
- Reproducibility of Results MeSH
- Retrospective Studies MeSH
- Sensitivity and Specificity MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH