The evaluation of voiding patterns. An analysis of frequency-volume charts and symptom scores

Abstract

This thesis is an analysis of frequency-volume charts (FVCs) and International Prostate Symptom Scores (IPSS) and their relations, based on 2 large databases: one with 24-hour FVCs of 1152 volunteers of all adult age groups without urological complaints, and one with 7-day FVCs of 378 urological outpatients; both databases included symptom scores.

A review of the literature on FVCs through the end of 2011 showed that especially since 1995 there has been an increase in the number of publications on FVCs, although most of these articles discuss using FVCs to evaluate therapeutic interventions. Several studies have outlined differences between populations, but from a diagnostic point of view, clear cut-off points are obviously lacking.

We presented normal ranges of FVC parameters as well as of the IPSS, comparing age groups and sexes. The mean volume/void decreased significantly with age in both genders. The IPSS increased significantly in consecutive age groups, but more prominent in men.

Compliance with recording a 7-day FVC was high: for the first 5 days, the level of completion was above 80% in most patients. From day 2, compliance decreased significantly with each day. Reliability of FVC parameters increased by day: at 5 days, reliability of 90% was achieved for all parameters. Beyond 5 days, the yield of additional recorded days was limited. This is the first study taking into account both compliance and reliability. We advocated an FVC duration of 3 days, but the length of time may be shortened or extended depending on the goal of the FVC.

Nocturia, as estimated by the IPSS and 7-day FVCs, was determined by mean nocturia in the FVC, the nocturia bother score, and patient age. The IPSS nocturia score overestimated nocturia derived from a 7-day FVC in most patients. When scoring IPSS nocturia question 7, patients seemed to have included a degree of bother.

The nocturnal polyuria index had wide variation but a normal distribution with a mean of 30%. The increase in the nocturnal polyuria index by age was small. The 95th percentile of the values was 53%. This value contrasts with the ICS definition of 33% (by which the prevalence of nocturnal polyuria is overestimated) but agrees with several other reports. Therefore, a better definition of nocturnal polyuria would be when the nocturnal polyuria index exceeds 53%.

The nocturnal voiding frequency depended on sleeping time and maximum voided volume but most of all on the nocturia index (nocturnal urine production / functional bladder capacity). Therefore, nocturia index is the best predictor of nocturia.

Guidelines should indicate more precisely which kind and duration of FVC or diary is advocated, which parameters are most important, and how the generated data should be used. Despite disappointing results reported in some studies, future studies should aim at further elucidating the potential (additional) diagnostic value of FVCs. The use of digital recording and processing of data will most certainly contribute to the diagnostic value of FVCs.