Test Volume Ratio Benchmarking to Identify and Reduce Low-Value Laboratory Utilization.

OBJECTIVES: We analyzed test volume data to identify low-value test utilization. We subsequently tracked the efficacy of interventions to improve test utilization by decreasing low-value testing. METHODS: Test volume data for analytes included in the Choosing Wisely guidelines were analyzed to identify population outliers. Outliers were defined by test volume ratios of either analyte to sodium or paired analytes to correct for variation in patient volumes at each site. Interventions to improve test utilization were targeted to outlier sites. Relative efficacy in reducing low-value testing was tracked at those sites. RESULTS: After appropriate data cleaning, test volume ratios for 17 analytes paired with sodium and 8 pairs of analytes were acquired from 108 national sites. A site with abnormally high Clostridium difficile/sodium ratio was selected for intervention, leading to a 71% decrease in C difficile tests. Two different interventions to decrease creatine kinase MB isoform (CKMB) testing were performed at two unique sites with abnormally high CKMB/troponin ratios. These interventions decreased CKMB by 11% and 98% at the different sites, showing the efficacy of the different kinds of interventions. CONCLUSIONS: Test volume ratio analysis and benchmarking enable identification of low-value test utilization.

Value and Use of Urinalysis for Myoglobinuria.

CONTEXT.­: Urine myoglobin testing is primarily indicated for diagnosis and risk assessment of kidney injury in patients with rhabdomyolysis. However, its utility is limited by a lack of rapid and reliable results. Myoglobin reacts positively for blood by urine dipstick, which can serve as an indicator of myoglobinuria. OBJECTIVE.­: To evaluate the performance and value of blood and red cell measurements by urinalysis as a surrogate test for myoglobinuria in routine clinical practice. DESIGN.­: This study is a retrospective observational study involving analysis of hemoglobin and red blood cell results by urinalysis in patients tested for urine myoglobin. RESULTS.­: A total of 13 139 urine myoglobin results from 88 Veterans Affairs facilities during a 15-year period ending in October 2014 were evaluated. Among methods used by each laboratory, qualitative urine myoglobin tests declined from 25 of 53 (47.1%) in 2000 to 5 of 77 (6.4%) in 2013. Of 7311 tests (55.6%) performed by quantitative methods with concomitant urinalysis, 3915 (53.5%) showed negative to trace blood results, of which myoglobin was 1000 µg/L or greater in 17 (0.4%). Among 1875 (25.5%) with 3+ (large) blood results, urine myoglobin was ≥1000 µg/L in 273 of 1533 (17.8%) with hematuria (≥5 red blood cells per microliter) and 109 of 342 (31.9%) without hematuria. CONCLUSIONS.­: Urinalysis results reliably predicted the absence of myoglobinuria and could be used to avert overtesting for urine myoglobin while also providing useful diagnostic information when urine myoglobin test results are not immediately available.

Aluminum Toxicity: Evaluation of 16-Year Trend Among 14 919 Patients and 45 480 Results.

CONTEXT: - Annual monitoring with serum aluminum measurements is recommended for dialysis patients who are susceptible to toxic accumulation from contaminated dialysis fluid or from ingestion of aluminum-containing medications. OBJECTIVE: - To evaluate long-term trends in serum aluminum concentrations and frequency of chronic toxicity. DESIGN: - A retrospective observational study was conducted by analyzing serum aluminum results obtained from the Veterans Affairs corporate data warehouse. Serum aluminum concentrations of 60 µg/L or greater were considered false positives and not indicative of chronic toxicity if another specimen retested within 45 days had a concentration below 20 µg/L. RESULTS: - A total of 45 480 serum aluminum results involving 14 919 patients and 119 Veteran Affairs facilities during a 16-year period ending in October 2016 were evaluated. The percentage of elevated (≥20 µg/L) serum aluminum results declined from 31.5% in 2000 to 2.0% in 2015. Average testing intervals changed from every 159 days in 2000 to every 238 days in 2015. Of 529 patients with serum aluminum concentrations of 60 µg/L or greater, 216 (40.8%) were retested within 45 days (average = 21 days); of these, 83 (38.4%) had concentrations below 20 µg/L after repeated measurements. Retesting rates increased with higher initial serum aluminum concentrations. CONCLUSIONS: - Aluminum toxicity, as assessed by serum levels, has substantially declined over time and is now rare. Many serum aluminum concentrations in the toxic range were not confirmed after retesting. Patients with toxic serum aluminum concentrations should be retested with another specimen before undergoing treatment or investigating sources of exposure to verify abnormal results.