Discussion: The study is clearly subject to caveats, chiefly that it was conducted at a single VA clinic and that only one aspect of the physician-patient encounter was addressed. Undoubtedly, patient’s preferences were influenced by the popular portrayal of physicians on TV shows. Nevertheless, given that hospitalists typically see older patients with whom they are not familiar, the initial clinical encounter may indeed by influenced by something as simple as wearing a white coat.
UA by Nephrologist Versus Hospital-Based Clinical Labs
Tsai JJ, Yeun JY, Kumar VA, Don BR. Comparison and interpretation of urinalysis performed by a nephrologist versus a hospital-based clinical laboratory. Am J Kidney Dis. 2005 Nov;46(5):820-829.
Background: Distinguishing the correct cause of acute renal failure is a frequent clinical dilemma for hospitalists, particularly diagnosing acute tubular necrosis (ATN), which is the most common cause of in-hospital acute renal failure. Although urinalysis with microscopy is the first test ordered on noting an abnormal serum creatinine, most hospitalists rely on the results generated by a laboratory technician. Anecdotally, many nephrologists have noted significant differences between urinalysis results performed by technicians and results found by nephrologists.
Methods: This study enrolled 26 patients hospitalized with acute renal failure on whom nephrology consultation was obtained. Urinalysis was performed both by laboratory personnel and a nephrologist (nephrologist A) who was blinded to the patient’s clinical information. Both sets of urinalysis results were independently used by nephrologist A and a second nephrologist (nephrologist B) to arrive at a clinical diagnosis for the patient, without having access to any other clinical information. These diagnoses were compared to the final diagnosis determined by the consulting nephrology service, who themselves did not have access to the diagnosis of either nephrologist A or B.
Results: The influence of having a nephrologist perform and interpret the urinalysis was striking. Nephrologist A was able to correctly diagnose 92.3% of cases based solely on his interpretation of the urinalysis. However, when given only the laboratory report of the urinalysis, both nephrologists were unable to diagnose most cases (23.1% for nephrologist A and 19.2% for nephrologist B). The major difference appeared to be in nephrologist A’s ability to find renal tubular epithelial (RTE) cells and RTE casts, which are pathognomonic of ATN. RTE cells and granular casts were frequently misinterpreted as squamous epithelial cells by laboratory personnel. This was particularly important as 81% of patients in the study had ATN as the primary cause of renal failure. Acanthocytes (dysmorphic red blood cells) were also missed by laboratory personnel in all six patients who were subsequently diagnosed with glomerulonephritis; nephrologist A correctly noted acanthocytes in five of these patients, and arrived at the correct diagnosis in all six patients.