Ghorbani Shireen, Nejad Amir, Law David, Chua Kathleen S, Amichai Meridythe M, Pimentel Mark
GI Motility Program, Cedars-Sinai Medical Center, Los Angeles (Shireen Ghorbani, Amir Nejad, Kathleen S. Chua, Meridythe M. Amichai, Mark Pimentel), California, USA.
Harbor UCLA Medical Center, Torrance (David Law), California, USA.
Ann Gastroenterol. 2015 Jan-Mar;28(1):87-93.
Case-control studies are vital for understanding the pathophysiology of gastrointestinal disease. While the definition of disease is clear, the definition of healthy control is not. This is particularly relevant for functional bowel diseases such as irritable bowel syndrome (IBS). In this study, a systematic review formed the basis for a prospective study evaluating the effectiveness of commonly used techniques for defining healthy controls in IBS.
A systematic review of the literature was conducted to identify case-control studies involving functional gastrointestinal disorders. "Lack of Rome criteria", self-description as "healthy" and the bowel disease questionnaire (BDQ) were common methods for identifying healthy controls. These 3 methods were then applied to a cohort of 53 non-patient subjects to determine their validity compared to objective outcome measures (7-day stool diary).
"Lack of Rome criteria" and "healthy" self-description were the most common methods for identifying healthy control subjects, but many studies failed to describe the methods used. In the prospective study, more subjects were identified as non-healthy using the BDQ than using either lack of Rome criteria (P=0.01) or "healthy" self-description (P=0.026). Furthermore, stool diaries identified several subjects with abnormal stool form and/or frequency which were not identified using lack of Rome criteria or the "healthy" question. Comparisons revealed no agreement (κ) between the different methods for defining healthy controls.
The definitions of healthy controls in studies of functional bowel diseases such as IBS are inconsistent. Since functional symptoms are common, a strict definition of "normal" is needed in this area of research.
病例对照研究对于理解胃肠道疾病的病理生理学至关重要。虽然疾病的定义很明确，但健康对照的定义却不明确。这对于诸如肠易激综合征（IBS）等功能性肠病尤为重要。在本研究中，一项系统评价为一项前瞻性研究奠定了基础，该前瞻性研究评估了在IBS中定义健康对照的常用技术的有效性。
对文献进行系统评价，以确定涉及功能性胃肠疾病的病例对照研究。“缺乏罗马标准”、自我描述为“健康”以及肠道疾病问卷（BDQ）是识别健康对照的常用方法。然后将这三种方法应用于53名非患者受试者的队列中，以与客观结果测量（7天大便日记）相比确定其有效性。
“缺乏罗马标准”和“健康”自我描述是识别健康对照受试者最常用的方法，但许多研究未能描述所使用的方法。在前瞻性研究中，使用BDQ识别出的非健康受试者比使用缺乏罗马标准（P = 0.01）或“健康”自我描述（P = 0.026）识别出的更多。此外，大便日记识别出了几名大便形状和/或频率异常的受试者，而这些受试者使用缺乏罗马标准或“健康”问题未被识别。比较显示，不同的健康对照定义方法之间没有一致性（κ）。
在诸如IBS等功能性肠病研究中，健康对照的定义不一致。由于功能症状很常见，因此在该研究领域需要对“正常”进行严格定义。
