Development and Initial Testing of the FLOW Instrument: Novel Assessment of Lower Urinary Tract Symptoms in Men

Abstract

Purpose: We sought to develop a method to assess lower urinary tract symptoms regardless of literacy and numeracy.

Materials and methods: We convened focus groups and developed a questionnaire based on 4 identified domains of urinary function, including frequency, incontinence (leakage), nocturia (overnight voiding) and weak stream. We pilot tested the novel FLOW (frequency, leakage, overnight voiding and weak stream) questionnaire in 64 men and performed quantitative analysis to determine internal consistency. Criterion validity was established via direct comparison to the AUA (American Urological Association) symptom score in a larger cohort of 161 men.

Results: Median time to complete the FLOW questionnaire was 18.0 seconds (IQR 15.8-21.0). The mean number of positive responses to the FLOW instrument was 1.7. Test-retest reliability was 0.91 and the Cronbach α was 0.67. In the validation cohort there was a significant correlation between FLOW scores and AUA symptom score (r = 0.63, p <0.001). All men regardless of health literacy completed FLOW. However, fewer men with low health literacy completed the AUA symptom score compared to men with adequate health literacy (81% vs 100%, p <0.001). For FLOW health literacy was unrelated to the median completion time (21.5 seconds), the median number of prompts needed (0) or the median score (2).

Conclusions: A critical analysis of the AUA symptom score using valid health literacy scales revealed that it is frequently not completed, requires prompting and takes longer to complete for men with low health literacy. The FLOW instrument represents a novel method to assess lower urinary tract symptoms in all men. It represents a valid alternative to the AUA symptom score.

Keywords: diagnostic errors; health literacy; lower urinary tract symptoms; prostatic hyperplasia; surveys and questionnaires.