Web‐based research of lower urinary tract symptoms that affect quality of life in elderly Japanese men: analysis using a structural equation model

Abstract
To investigate the distribution of lower urinary tract symptoms (LUTS) in elderly Japanese men, to clarify which variables contributed to medical care-seeking behaviour, and to construct a structural-equation model (SEM) to explain overall quality of life (QoL). A dataset was obtained from 662 Japanese men aged 50-79 years who participated in the programme by accessing a website via the Internet between 10.30 hours on 19 February 2003 and 10.30 hours on 24 February 2003. The participants were queried about their International Prostate Symptom Score (IPSS), bother, QoL index and medical care-seeking behaviour. Of the 662 participants, 314 reported intending to seek medical care for LUTS (intention group); the remaining 348 answered that they did not intend to see a doctor (no-intention group). The characteristic of weak stream had the strongest correlation with the QoL index, not only in the intention (r = 0.58) but also in the no-intention group (r = 0.48). Among several SEMs proposed, one that included a latent variable termed 'QoL sensitivity' was the most appropriate to explain overall QoL. In this model it was assumed that 'QoL sensitivity' was affected by other latent variables, termed the 'voiding symptom factors' and 'storage symptom factors', and affected the degree of bother related to each symptom. In Japanese men, voiding symptoms, especially weak stream, contributed to overall QoL for medical care-seeking behaviour. Differences in 'QoL sensitivity' among men may be one of the reasons why symptomatic severity is not always correlated with symptom-related bother.