Judgment analysis in clinical nephrology

To ameliorate the clinical performance of nephrologists, improving their cl inical judgment is crucial. No methodology for judgment analysis in nephrol ogy is currently available. Therefore, we designed a trial to assess the in traphysician consistency of the judgment of typical non-end-stage renal dis ease (ESRD) patients by 24 board-certified nephrologists. The participants were asked to analyze cases to determine the interobserver variability with respect to diagnosis, therapy, prognosis, and strategy of follow-up. They were unaware that every patient was presented on 2 occasions separated by a period of 6 months. Of the 1,288 questionnaires that were completed, 28 ca ses belonged to 1 of the following 3 groups: (A) patients once with, once w ithout renal histology, (B) patients twice without histology, and (C) patie nts twice with histology. Only cases of group (A) differed at the 2 occasio ns of assessment with respect to knowledge of histology. The results from t he first and second assessment were compared and analyzed. The median (95% confidence interval) percentages of changed diagnoses were 64% (59% to 68%) , 50% (44% to 62%), and 33% (26% to 47%) in groups A, B, and C, respectivel y, indicating large intraobserver variability. The frequency of changes in diagnoses declined with the degree of confidence in the first diagnosis in ail 3 groups. The subjective desire to know the histology was without impac t on the frequency of changes in diagnoses. However, a knowledge of the his tology enhanced the degree of confidence in the diagnoses. Interestingly, t he enormous variability in changing diagnoses from one analysis to the othe r was not reflected by corresponding changes in the judgment of prognosis, therapy to be prescribed, or strategy of follow-up. The individual judgment with respect to diagnosis of clinical cases is inconsistent and highly dep endent on the subjective degree of confidence in the diagnosis. The practic al relevant consequences traditionally derived from a diagnosis (therapy, p rognosis, and strategy of follow-up) are only marginally, if at ail, affect ed by changing the diagnosis. Thus, the utility of "diagnosis" for judgment analysis in clinical nephrology should be reconsidered. (C) 1999 by the Na tional Kidney Foundation, Inc.