The accuracy of 1997 Partin Tables' lymph node invasion (LNI) predictions exhibits important variability in different testing populations. We explored the LNI predictive accuracy in radical prostatectomy (RP) patients from Montreal, Canada. Moreover, we assessed the extent of change in predictive accuracy related to a modification of PSA coding from categorical to continuous.
We used pretreatment serum PSA, clinical stage, and biopsy Gleason sum from 537 men treated with RP to compare predicted and observed rates of LNI. Accuracy was quantified with receiver-operating characteristics curves.
Accuracy was 0.760 in 369 evaluable patients, when categorically coded pretreatment PSA (0-4, 4.1-10, 10.1-20, 20.1+) was combined with clinical stage and biopsy Gleason sum. A 2.7% accuracy increase was noted when categorically coded PSA was replaced with continuously coded values.
Partin Tables' LNI predictions showed comparable accuracy to a community-based sample from the United States (0.766), and to a recent, multi-institutional sample (0.740). However, accuracy was lower than reported in internal (0.818), and external (0.837) academic, validation cohorts. Accuracy of LNI predictions was appreciably higher, when continuously coded PSA was used.
To examine the external validity of the United Kingdom English version of the LittlEARS(®) Auditory Questionnaire with English-speaking families of Canadian children with normal hearing.
The United Kingdom English version of the LittlEARS was administered to English-speaking families of 130 children with normal hearing in Ontario, Canada. Total scores for these children were compared to German-derived normative values.
There was no significant difference between Canadian and German norms when using the United Kingdom English version of the LittlEARS Auditory Questionnaire.
The United Kingdom English version of the LittlEARS Auditory Questionnaire is appropriate for use with English-speaking families of normal hearing Canadian children.
The objective was to validate the diagnoses of peripheral arterial disease (PAD) in the legs, obtained from national registers in Denmark.
In total, 1435 registered cases of PAD were identified in the Danish National Patient Registry among 57,053 middle aged participants from the Danish Diet, Cancer and Health cohort study. Validation was performed by reviewing all medical records using pre-specified criteria for a diagnosis of PAD.
The overall positive predictive value (PPV) of PAD diagnoses was 69.4% [95% confidence interval (CI) 67.0-71.7]. The PPV of diagnoses given in departments of vascular surgery was significantly higher than diagnoses given in other departments: 71.9% (95% CI 69.2-74.4) versus 58.3% (95% CI 52.2-64.2), respectively. In a sub-study, 141 potential cases of PAD also registered in the Danish National Vascular Registry were evaluated, and a PPV of 87.9% (95% CI 81.4-92.4) was found for these diagnoses.
More than 30% of the diagnoses of PAD notified in the Danish National Patient Registry were not valid, stressing the importance of validation when using register information for research purposes. In contrast, diagnoses obtained from the Danish National Vascular Registry had a high validity ready for use without further validation.
An index to predict individual postmenopausal bone loss is presented. The index is developed by means of data from a 10-year prospective Norwegian study in which bone mass of the distal forearm was measured annually in 73 women. All the women were 47 years old and premenopausal at inclusion. Independent risk factors for postmenopausal bone loss were identified by applying multivariate regression analysis on anthropometric, biochemical, nutritional, and life-style variables measured at menopause. The analysis identified low body weight, reduced renal phosphate reabsorption, and smoking as significant independent risk factors, and by means of these three factors a predictive index for postmenopausal bone loss was developed. This index was validated by using data from a 10-year longitudinal Dutch study, in which bone mass of the proximal radius was measured annually in 86 women, aged between 49 and 57 years and perimenopausal at inclusion. We defined women with the highest index score as "high-risk persons." According to this definition approximately 25% of the perimenopausal women were classified as high-risk persons, and the estimated sensitivity/specificity/positive predictive power were 36%, 89%, and 74%, respectively, when used to select women with a postmenopausal bone loss above average. We conclude that the index may be helpful in identifying healthy perimenopausal women in whom bone mass measurements should be considered.
The performance characteristics and diagnostic accuracy of a new rapid automated quantitative immunoturbidimetric D-dimer assay, Auto-Dimer (Biopool, Umeå, Sweden) were evaluated in a population of 135 outpatients with suspected deep-vein thrombosis of a lower limb. Enzyme-linked immunosorbent assay was used as the reference method. The Auto-Dimer assay showed good reproducibility. The correlation between Auto-Dimer and enzyme-linked immunosorbent assay was high (r = 0.91, p
Work Package 3 of the Prevention of Falls Network Europe has evaluated measurement properties of clinical balance measures to be used to: (1) select participants for interventions with the goal to prevent falls in older people, and (2) assess the results of such intervention on balance function. Inclusion in a fall prevention study may be based on measures identifying subjects who have impaired balance or increased risk of future falls. We propose that an appropriate statistical method to analyse discriminative ability of a balance measure is discriminant analysis or logistic regression analysis. The optimal cut-off score is best determined by plotting a receiver-operating-characteristic curve for different cut-off values. The evaluation of predictors for risk of future falls should be based on a study design with a prospective data collection of falls. Sensitivity to change is a measurement property needed to evaluate the outcome of an intervention. The standardized response mean is frequently encountered in the literature and is recommended as a statistical measure of sensitivity to change in the context of an intervention study. Adequate reliability is a prerequisite for consistent measurement. Relative reliability may be reported as an intraclass correlation coefficient and absolute reliability as the within-subject standard deviation (s(w)), also called standard error of measurement. When measurement error is proportional to the score, calculation of a coefficient of variation can be considered. In a second paper, the authors will evaluate clinical balance measures for use in fall prevention studies based upon criteria recommended in this report.