Nine hundred fifty-one emergency and 997 nonemergency patients seeking endodontic treatment were the basis of this study. Variables of interest were 10 pain descriptors, percussion and palpation tests, causative factors, and paired pulpal and periapical diagnoses. A higher number of patients suffering from symptomatic pulpal conditions sought emergency care. Odds of caries being a causative fac...

Cost-effectiveness (CE) ratios vary considerably, not only across interventions, but within single interventions. Using a simple decision-tree model of the treat-vs no-treat decision to organize the analysis, four potential errors leading to these within-treatment differences in CE ratios are identified. These errors arise from estimates relating to 1) prior probabilities of disease; 2) treatme...

Background: Deficits in executive functions have been widely reported to characterise individuals with ADHD. The aim of this study was to evaluate the utility of a range of executive function measures for identifying children with ADHD. Method: Eighty-three children with ADHD and 50 normally-developing children without ADHD were assessed on measures of inhibition, set-shifting, planning, proble...

Traditionally, the receiver operating characteristic (ROC) curve for a diagnostic test plots true positives (sensitivity) against false positives (one minus specificity). However, this representation brings with it several drawbacks. A transformation to positive and negative likelihood ratio co-ordinates, scaled by base-ten logarithms, offers several advantages. First we motivate the use of pos...

The accurate measurement of polycyclic aromatic hydrocarbons (PAH), polycyclic aromatic sulfur heterocycles (PASH), and their alkylated homologues is essential at all levels of risk assessment and remedial decision-making. In the field of environmental forensics, diagnostic ratios of these compounds are used to delineate fossil fuel-based sources from one another and to assess the degree of wea...

AIM Early breast cancer detection is important for intervention and prognosis. Advances in treatment and outcome require diagnostic tools with highly positive predictive value. PURPOSE To study the potential role of quantitative MRI (qMRI) using T1/T2 ratios to differentiate benign from malignant breast lesions. METHODS A cross-sectional study of 69 women with 69 known or suspicious breast ...

This paper clarifies two important concepts in clinical epidemiology: the slope of a receiver operating characteristic (ROC) curve and the likelihood ratio. It points out that there are three types of slopes in an ROC curve--the tangent at a point on the curve, the slope between the origin and a point on the curve, and the slope between two points on the curve. It also points out that there are...