Overview of the Alberta Kidney Disease Network

<p>Abstract</p> <p>Background</p> <p>The Alberta Kidney Disease Network is a collaborative nephrology research organization based on a central repository of laboratory and administrative data from the Canadian province of Alberta.</p> <p>Description</p> <p>The laboratory data within the Alberta Kidney Disease Network can be used to define patient populations, such as individuals with chronic kidney disease (using serum creatinine measurements to estimate kidney function) or anemia (using hemoglobin measurements). The administrative data within the Alberta Kidney Disease Network can also be used to define cohorts with common medical conditions such as hypertension and diabetes. Linkage of data sources permits assessment of socio-demographic information, clinical variables including comorbidity, as well as ascertainment of relevant outcomes such as health service encounters and events, the occurrence of new specified clinical outcomes and mortality.</p> <p>Conclusion</p> <p>The unique ability to combine laboratory and administrative data for a large geographically defined population provides a rich data source not only for research purposes but for policy development and to guide the delivery of health care. This research model based on computerized laboratory data could serve as a prototype for the study of other chronic conditions.</p

Assay precision and risk of misclassification at rule-out cut-offs for high-sensitivity cardiac troponin

Clinical trials and guidelines support the use of very low high-sensitivity cardiac troponin (hs-cTn) results to rule-out a myocardial infarction (MI) ( 1) ). The International Federation of Clinical Chemistry and Laboratory Medicine Committee on Clinical Applications of Cardiac Biomarkers committee, through a modeling approach, suggests assays need to have a lower limit near 3 ng/L and an analytical variation of 10% below 7 ng/L if these low values are to perform consistently in practice ( 2) ). Our objectives for the present study were to assess: i) if any type of instrument or individual instrument could achieve a coefficient of variation (CV) of ≤10% at very low hs-cTn cut-offs (i.e., targets) recommended in clinical pathways; ii) the frequency of results at the hs-cTn target, above the target and below the target, with the latter group representing potential misclassification to the low risk group where the target level would in the intermediate risk range.<br/

The Fracture Risk Assessment Tool (FRAX®) predicts fracture risk in patients with chronic kidney disease

The Fracture Risk Assessment Tool (FRAX®) was developed to predict fracture risk in the general population, but its applicability to patients with chronic kidney disease (CKD) is unknown. Using the Manitoba Bone Mineral Density (BMD) Database, we identified adults not receiving dialysis with available serum creatinine measurements and bone densitometry within 1 year. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Incident major osteoporotic fractures and hip fractures were ascertained from population-based health care databases. The performance of FRAX, derived without and with BMD, was studied in relation to CKD stage. Among 10,099 subjects (mean age 64 ± 13 years, 13.0% male), 2,154 had eGFR 30-60 mL/min/1.73 m2 (CKD stage 3) and 590 had eGFR <30 mL/min/1.73 m2 (CKD stages 4-5). During a 5-year observation period, 772 individuals experienced a major osteoporotic fracture and 226 had a hip fracture. FRAX predicted risk for major osteoporotic fracture and hip fracture in all eGFR strata. For every standard deviation increase in FRAX score derived with BMD, the hazard ratio (HR) for hip fracture was 4.54 (95% confidence interval [CI] 3.57-5.77) in individuals with eGFR ≥ 60 mL/min/1.73m2, 4.52 (95% CI 3.15-6.49) in individuals with eGFR 30-60 mL/min/1.73m2, and 3.10 (95% CI 1.80-5.33) in individuals with eGFR <30 mL/min/1.73m2. The relationship between FRAX and major osteoporotic fracture was stronger in those with CKD compared to those with preserved eGFR. These findings support the use of FRAX to risk stratify patients with non-dialysis CKD for major osteoporotic fractures and hip fractures