Patients with new onset haematuria: assessing the discriminant value of clinical information in relation to urological malignancies.

Abstract

BACKGROUND: There is little information available to assist general practitioners (GPs) in deciding which patients with haematuria are likely to have a malignancy. AIM: To derive discriminant functions for specific items or clusters of clinical history information in relation to the categorisation of patients presenting to the 'open access' haematuria clinic in Hull. DESIGN OF STUDY: Recruitment of patients via an 'open-access' haematuria clinic. SETTING: A consecutive series of 363 patients aged between 18 and 80 years who attended the clinic. METHOD: Between February 1999 and October 1999 clinical history information derived from the participating patients was compared with the patients' diagnoses. Diagnoses were established by a combination of cystoscopy and radiological assessments and rechecked against the patient records and the hospital patient administration system two to three months later. RESULTS: A number of individual variables seemed to be particularly helpful in discriminating malignancies. However, when indicants were combined using regression shrinkage techniques, only the following variables were preserved: age, sex, type of haematuria, number of episodes of haematuria, hesitancy, poor urinary stream, smoking history, and history of urinary tract infections. CONCLUSION: It is possible to generate helpful discriminant information to assist GPs in making more appropriate decisions in a difficult area of clinical practice. However, it remains a matter of judgement as to how representative the study population is likely to be compared with all haematuria patients encountered in primary care. We have reasonable confidence in the general applicability of the rules for macroscopic haematuria: however, it seems likely that the prediction rules outlined for microscopic haematuria have their greatest relevance once a patient has been referred by a GP. In developing the work further and testing out the discriminators identified in this study, we propose that a primary care-based project now needs to be undertaken focusing on microscopic haematuria with a particular emphasis on addressing selection biases. In addition, there is a more general need to assess the reliability of all the suggested items of clinical discriminant information.