Using structural equation modelling to explore the relationship between insomnia, anxiety and depression to the severity of BPS/IC: a cross-sectional study in Chongqing, China.

Abstract

Despite the high prevalence of insomnia, anxiety and depression in patients with bladder pain syndrome/interstitial cystitis (BPS/IC), their clinical impact is often overlooked. To address this gap, our study systematically investigated whether these three comorbidities impact BPS/IC severity. This cross-sectional study included 237 patients with BPS/IC recruited via convenience sampling from Shapingba Hospital affiliated to Chongqing University (Shapingba District People's Hospital of Chongqing) and Chongqing Liangjiang Minsheng Hospital in Chongqing, China, between 24 August 2023 and 21 November 2023. Apart from demographic characteristics, BPS severity was assessed using the O'Leary-Sant interstitial cystitis questionnaire, insomnia was assessed using the Athens Insomnia Scale and anxiety and depression were assessed using Zung's Self-rating Anxiety Scale and Zung's Self-rating Depression Scale, respectively. The structural equation model (SEM) was used to analyse the role of insomnia, anxiety and depression on the severity of BPS/IC. The proportion of severe disease, insomnia, anxiety and depression in participants was 49.37%, 70.89%, 43.88% and 47.26%, respectively. The analysis of SEM indicated that insomnia (<i>β</i>=0.294, p<0.001) and anxiety (<i>β</i>=0.364, p<0.001) were associated with BPS severity, but depression showed no significant association (<i>β</i>=0.042, p=0.674). According to the mediating analysis, the association between insomnia and the disease was attributable to both direct effects of insomnia (55.5%) and indirect effects involving anxiety conditions (44.5%). Our findings indicate that insomnia is associated with BPS/IC severity both directly and indirectly through anxiety in patients with BPS/IC. These results further support the use of psychological and sleep interventions for BPS/IC.