Login to Access Video or Poster Abstract: MP96-11
Sources of Funding: This was funded in part by the 2016 AAMC Clinical Care Innovation Pilot Award

Introduction

Concerns about the intermittency of microhematuria (MH) have led to changes in management guidelines. Currently, a single positive urinalysis (≥3 RBC/hpf) is considered enough to warrant a diagnostic evaluation. However, this practice is supported by low-level evidence. It was our hypothesis that a follow up urinalysis (FUUA) adds prognostic information to the work up of MH.

Methods

Using a multicenter electronic data warehouse, we retrospectively identified all patients from 2012-2015 with a new diagnosis of MH. Characteristics of those who did and did not complete a FUUA were compared. Severity of MH on FUUA was related and compared to severity on the initial sample. In patients who had a FUUA, regression modeling was used to determine the association of a positive FUUA with a diagnosis of bladder cancer, kidney cancer, and nephrolithiasis after adjusting for age, sex, and degree of MH on index UA.

Results

_x000D_ Of the 7,879 patients identified with MH, 4,270 (54.1%) had a FUUA at a median time of 71 days after initial UA. Patients who had a FUUA were older (57 vs 53, p<0.001), more commonly female (57% vs. 53%, p=0.001), but had no differences among races (p=0.45). Degree of MH on index UA did not relate to completion of a FUUA (p=0.08). Most FUUA (65.8%) were negative and there was a weak correlation between degree of MH on initial UA and FUUA (rs=0.19, p<0.001), (Figure 1). After adjusting for age, gender and severity of MH on index UA, positive FUUAs were associated with increased odds of being diagnosed with bladder cancer, kidney cancer, and nephrolithiasis compared to a negative FUUA (Table 1). Any FUUA with 11 or more RBC/hpf increased the risk of bladder cancer diagnosis significantly over a negative FUUA. Conversely, in kidney cancer and urolithiasis, compared to a negative FUUA, only a FUUA with 100+ RBC/hpf increased the odds of diagnosis.

Conclusions

A positive FUUA may help to better identify patients with bladder cancer, kidney cancer, and urolithiasis-- but only at severe thresholds of RBC/hpf.

Funding

This was funded in part by the 2016 AAMC Clinical Care Innovation Pilot Award