Significance of intermittency in men with lower urinary tract symptoms

To determine the relationship between the symptom of intermittency, objective evidence of intermittency on uroflow traces, benign prostatic enlargement, and bladder outlet obstruction (BOO) in men with lower urinary tract symptoms (LUTS).

The prevalence of the symptom of intermittency was determined from a symptom questionnaire in 165 men presenting with LUTS. Objective evidence of intermittency during voiding was assessed from uroflow traces, and prostate volume was measured by transrectal ultrasound. Combined pressure-flow studies were performed to determine the presence or absence of BOO.

There was relatively poor agreement between the symptom of intermittency and objective evidence of its presence. Of the 35 patients who reported intermittency most or all of the time, 21 showed no objective evidence of intermittency on uroflowmetry. The symptom of intermittency was not significantly related to the presence of BOO (P = 0.42) and the group-specific urethral resistance factor (URA) did not differ significantly (P = 0.87) between those men who complained of intermittency and those who did not (median URA, 35 versus 32 cm H2O). However, objective evidence of intermittency on uroflow traces was significantly related to BOO (P = 0.016), and those patients with objective evidence of intermittency had higher URA values (median, 43 versus 32 cm H2O). Objective evidence of intermittency had a specificity of 98% and positive predictive value of 92% for the presence of BOO. Neither the symptom of intermittency nor objective evidence of its presence was significantly related to prostate size.

Although the symptom of intermittency does not seem to be related to BOO or prostate size, objective evidence of intermittency on flow curve traces is specific for outflow obstruction, and as such its presence could potentially be of value in the assessment of men with lower urinary tract symptoms.