RAND Interstitial Cystitis Epidemiology Study

The RAND Interstitial Cystitis Epidemiology Study (RICE) is an observational study that sought to develop a case definition for Bladder Pain Syndrome (BPS)/Interstitial Cystitis (IC) with known sensitivity and specificity and to estimate the prevalence of the condition, which at the time had never been done using a large-population model. BPS/IC, which is clinically diagnosed based on patient-reported symptoms, is a poorly understood condition that can cause significant disability. An expert panel developed a case definitions of BPS/IC based on a review of medical literature. This definition was tested on 599 adult women diagnosed with BPS/IC or other conditions characterized by pelvic symptoms. Testing revealed that no single epidemiological definition demonstrated both high sensitivity and high specificity, so two definitions were developed: one of high sensitivity/low specificity and one of low sensitivity/high specificity. Using these two definitions, researchers then screened 96,995 US households to identify women who had bladder symptoms. Those with symptoms underwent a secondary, more intensive screening and were asked to provide more information regarding symptoms, medical history, medical treatments, impact on daily life, physical and mental health, and demographic information. Multivariate modeling was used to construct population and non-response weights. Weighted data was used to calculate prevalence estimates for both definitions and estimate the number of women affected.兰德间质性膀胱炎流行病学研究（RAND Interstitial Cystitis Epidemiology Study, 简称RICE）是一项观察性研究，旨在制定兼具已知灵敏度与特异度的膀胱疼痛综合征（Bladder Pain Syndrome, BPS）/间质性膀胱炎（Interstitial Cystitis, IC）病例定义，并估算该疾病的患病率——而彼时尚无基于大人群模型的此类患病率估算研究。BPS/IC主要依据患者自述症状进行临床诊断，目前对该疾病的认知仍较为有限，但其可导致严重的功能障碍。 专家组通过系统梳理医学文献，制定了BPS/IC的病例定义。该定义曾在599名已确诊BPS/IC或其他盆腔症状相关疾病的成年女性群体中开展验证。验证结果显示，尚无单一流行病学定义可同时具备高灵敏度与高特异度，因此研究人员最终确立了两类病例定义：一类为高灵敏度/低特异度定义，另一类为低灵敏度/高特异度定义。 基于上述两类病例定义，研究人员随后对96995户美国家庭开展筛查，以甄别存在膀胱症状的女性。出现症状的受试者需接受第二轮更为细致的强化筛查，并被要求提供更多相关信息，包括症状详情、病史、治疗方案、对日常生活的影响、身心健康状况以及人口统计学资料。 研究采用多变量建模方法构建人群权重与无应答权重，基于加权后的数据分别计算两类病例定义下的患病率估算值，并推算受影响女性的总人数。