title: A blind controlled trial of phase-contrast microscopy by two observers for evaluating the source of haematuria.
abstract: Two observers, unaware of each other's findings and of the diagnosis, examined red cells in the urine of 109 patients by phase-contrast microscopy. All specimens were examined uncentrifuged by inverted microscopy, and 48 of the 109 were also examined under a light microscope after centrifugation. We were unable to confirm with either method the close correlation between red-cell morphology and diagnosis reported in previous studies, and our 2 observers differed in their interpretation on 38% of occasions. Proteinuria associated with the presence of casts in uncentrifuged urine examined by inverted microscopy was a better indication than red-cell morphology of renal parenchymal disease.
mesh_terms: D002498:Centrifugation; D002986:Clinical Trials as Topic; D003080:Cold Temperature; D003951:Diagnostic Errors; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000473:pathology; D005188:False Negative Reactions; D006417:Hematuria / Q000209:etiology / Q000473:pathology / Q000652:urine*; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000175:diagnosis; D008858:Microscopy, Phase-Contrast