CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Anne Paxton
November 2015—Tim Skelton, MD, PhD, knows a fair amount about how to enhance the clinical value of urinalysis. It’s a subject that, as medical director of the core laboratory and laboratory informatics at Lahey Hospital and Medical Center in Burlington, Mass., he’s been focused on for the past three years. But he didn’t exactly set out to become an expert in that particular area. He was mainly trying to figure out why his laboratory was experiencing repeated urinalysis quality assurance failures.
In a presentation at this year’s American Association for Clinical Chemistry annual meeting, Dr. Skelton related his frustration in trying to meet the clinical tolerances in testing for protein, glucose, occult blood, and ketones. “We got new analyzers in, we retrained technologists, we tried to change our procedures, we told them not to put certain specimens on. And none of those things helped.” Added to that, the leukocyte esterase, nitrates, and occult blood tests done by dipstick frequently gave false-negative results. “The current method [of urinalysis] does not meet the performance characteristics required for good patient care” was the conclusion of a June 2012–January 2014 QA project at Lahey Health System.
As an example of the type of quality assurance problems that were cropping up, in July 2013 the laboratory performed split patient sample comparisons across different instruments: the main dipstick reader in the main hospital, a small backup dipstick reader, and a separate hospital’s medium-sized dipstick reader. “We had three techs at different hospitals do a manual interpretation and tried to compare them, and what we found was a huge variation. The same specimen could come in at 15, trace, or negative for ketones, depending on which tech was reading it. Proteins could vary from greater than 300 mg/dL to 30–100 mg/dL.” Clinically, those results require very different actions, he notes. “So we needed to change the system.”
At the time, the laboratory reflexed to a microscopic analysis only when a chemistry was positive. “We realized that wasn’t adequate. It wasn’t possible to get what we needed clinically from the urine dipstick; based on the evidence, you needed a microscopic analysis on every urine specimen.”