Estimating skills level in recreational skiing: Development and validation of a practical multidimensional instrument.

Skiing and snowboarding are both popular recreational alpine sports, with substantial injury risk of variable severity. Although skills level has repeatedly been associated with injury risk, a validated measure to accurately estimate the actual skills level without objective assessment is missing. This study aimed to develop a practical validated instrument, to better estimate the actual skills level of recreational skiers, based on the criteria of the Dutch Skiing Federation (DSF), and covering five different skill domains. A sample of Dutch recreational skiers (n = 84) was asked to fill in a questionnaire reflecting seven, a priori chosen predictors by expert opinion, to ski downhill and to be objectively evaluated by expert assessors. The instrument was developed to have a multidimensional character and was validated according to the TRIPOD guideline (Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis). The sample reported an overall incorrect self-reported estimation of their skills, compared with the observed skill score. The instrument showed good calibration and underwent multiple validation methods. The estimated skills score showed to be closer to the observed scores, than self-reportage. Our study provides a practical, multidimensional, and validated instrument to estimate the actual skills level. It proved to better reflect the actual skills levels compared with self-reportage among recreational skiers.

Decline in residual renal function in automated compared with continuous ambulatory peritoneal dialysis.

BACKGROUND AND OBJECTIVES: We compared the decline of RRF in patients starting dialysis on APD with those starting on CAPD, because a faster decline on APD has been suggested. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: NECOSAD patients starting dialysis on APD or CAPD with RRF at baseline were included and followed for 3 years. Residual GFR (rGFR) was the mean of urea and creatinine clearances. Differences in yearly decline of rGFR were estimated in analyses with linear repeated measures models, whereas the risk of complete loss of RRF was estimated by calculating hazard ratios (HRs) for APD compared with CAPD. As-treated (AT) and intention-to-treat (ITT) designs were used. All of the analyses were adjusted for age, gender, comorbidity, and primary kidney disease and stratified according to follow-up and mean baseline GFR. RESULTS: The 505 CAPD and 78 APD patients had no major baseline differences. No differences were found in the analyses on yearly decline of rGFR. APD patients did have a higher risk of losing RRF in the first year (ITT crude HR 2.43 [confidence interval 95%, 1.48 to 4.00], adjusted 2.66 [1.60 to 4.44]; AT crude 1.89 [1.04 to 3.45], adjusted 2.15 [1.16 to 3.98]). The higher risk of losing all RRF was most pronounced in patients with the highest rGFR at baseline (ITT; crude 3.91 [1.54 to 9.94], adjusted 1.85 to 14.17). CONCLUSIONS: The risk of losing RRF is higher for patients starting dialysis on APD compared with those starting on CAPD, especially in the first year.

Performance of the Cockcroft-Gault, MDRD, and new CKD-EPI formulas in relation to GFR, age, and body size.

BACKGROUND AND OBJECTIVES: We compared the estimations of Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations to a gold standard GFR measurement using (125)I-iothalamate, within strata of GFR, gender, age, body weight, and body mass index (BMI). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: For people who previously underwent a GFR measurement, bias, precision, and accuracies between measured and estimated kidney functions were calculated within strata of the variables. The relation between the absolute bias and the variables was tested with linear regression analysis. RESULTS: Overall (n = 271, 44% male, mean measured GFR 72.6 ml/min per 1.73 m(2) [SD 30.4 ml/min per 1.73 m(2)]), mean bias was smallest for MDRD (P < 0.01). CKD-EPI had highest accuracy (P < 0.01 compared with Cockcroft-Gault), which did not differ from MDRD (P = 0.14). The absolute bias of all formulas was related to age. For MDRD and CKD-EPI, absolute bias was also related to the GFR; for Cockcroft-Gault, it was related to body weight and BMI as well. In all extreme subgroups, MDRD and CKD-EPI provided highest accuracies. CONCLUSIONS: The absolute bias of all formulas is influenced by age; CKD-EPI and MDRD are also influenced by GFR. Cockcroft-Gault is additionally influenced by body weight and BMI. In general, CKD-EPI gives the best estimation of GFR, although its accuracy is close to that of the MDRD.

Similar survival on automated peritoneal dialysis and continuous ambulatory peritoneal dialysis in a large prospective cohort.

BACKGROUND AND OBJECTIVES: Automated peritoneal dialysis (APD) is increasingly used in comparison with continuous ambulatory peritoneal dialysis (CAPD). Although APD is expected to improve survival, convincing evidence of major advantages is lacking. The objective was to investigate whether overall mortality and technique failure of incident dialysis patients treated with APD are different from those treated with CAPD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients on APD or CAPD at 3 mo after start of dialysis were selected from a prospective multicenter cohort study in incident dialysis patients (NECOSAD). Overall mortality was studied with an intention-to-treat design; the event was death. Technique failure was studied with an as-treated design; the event was a switch of dialysis modality. Hazard ratios (HRs) were calculated with a follow-up of 5 yr. The HRs were adjusted for gender, age, primary kidney disease, comorbidity, residual GFR, urine production and plasma albumin at 3 mo after inclusion. RESULTS: Eighty-seven APD and 562 CAPD patients were included. In the intention-to-treat analysis 154 CAPD and 21 APD patients died. The crude HR for overall mortality was 0.98 (95% CI: 0.62-1.54), the adjusted HR was 1.09. In the as-treated analysis 238 CAPD and 34 APD patients switched therapy, whereas 91 CAPD and 7 APD patients died. The crude HR for technique failure was 0.92 (95% CI: 0.64-1.31) and did not change after adjustment. CONCLUSIONS: No difference was found in overall mortality and technique failure for APD compared with CAPD in incident dialysis patients.