Supplementary Material for: Predicting Therapeutic Intervention for Patients with Quiescent Crohn’s Disease Using the Small Bowel Capsule Endoscopy Score

Introduction: Small bowel (SB) capsule endoscopy (SBCE) is a sensitive modality for screening the entire SB of patients with Crohn’s diseases (CD); however, the prognostic impact of the results is unclear. We evaluated the ability of the SBCE score to predict therapeutic intervention for patients with CD and SB lesions without clinical symptoms as well as negative C-reactive protein (CRP) levels.
Methods: Fifty-six patients who underwent a patency evaluation and had a CD activity index (CDAI) score <150 mg/dL and CRP level <0.5 mg/dL were included. Twenty-one and 35 patients had CD classified as Montreal classifications L1 and L3, respectively. The initial SBCE scores were subsequently grouped according to the presence or absence of intervention based on cutoff values. We examined whether the scores could predict the need for therapeutic intervention at 1 year, 2 years, and 5 years. The CD activity in capsule endoscopy (CDACE) score was used as the SBCE score.
Results: The median observation period was 1326 days. Twenty-one patients received therapeutic intervention. There were significant differences between patients with and without treatment intervention according to the CDACE cutoff value of 420 at 1 year, 2 years, and 5 years. Significant differences between patients with Montreal classification L1 with and without intervention were observed at 1 year and 2 years. The CDACE score was moderately and strongly correlated with the Lewis score and capsule endoscopy CDAI score, respectively (Spearman rank correlation coefficient: ρ=0.6462 and ρ=0.9199, respectively; p<0.0001).
Conclusion: A CDACE score ≥420 is predictive of intervention after 1 year for patients with CD, a CDAI score <150, and CRP level <0.5 mg/dL. A larger study with a prospective design is necessary to validate our findings.

## 引言
小肠胶囊内镜（Small bowel capsule endoscopy, SBCE）是筛查克罗恩病（Crohn’s disease, CD）患者全小肠病变的敏感检测手段，但其检查结果对预后的影响尚不明确。本研究旨在评估SBCE评分对无临床症状且C反应蛋白（C-reactive protein, CRP）水平正常的克罗恩病合并小肠病变患者接受治疗性干预的预测价值。

## 方法
本研究纳入56例接受肠道通畅性评估，且克罗恩病活动指数（Crohn’s disease activity index, CDAI）评分<150、CRP水平<0.5 mg/dL的患者。其中21例患者的克罗恩病按蒙特利尔分类（Montreal classification）为L1型，35例为L3型。随后根据临界值将初始SBCE评分分为干预组与非干预组，分析该评分对患者在随访1年、2年及5年时是否需要接受治疗性干预的预测能力。本研究所用SBCE评分为胶囊内镜克罗恩病活动指数（CD activity in capsule endoscopy, CDACE）评分。

## 结果
本研究的中位随访时长为1326天，共计21例患者接受了治疗性干预。在随访1年、2年及5年时，以CDACE评分420为临界值，接受干预与未接受干预的患者间评分差异均具有统计学意义。在蒙特利尔分类为L1型的患者中，随访1年及2年时，干预组与非干预组的CDACE评分差异同样具有统计学意义。CDACE评分分别与Lewis评分及胶囊内镜CDAI评分呈中等强度及强相关（斯皮尔曼等级相关系数分别为ρ=0.6462、ρ=0.9199，均p<0.0001）。

## 结论
对于克罗恩病患者，若其CDAI评分<150、CRP水平<0.5 mg/dL，则CDACE评分≥420可预测其1年后需接受治疗性干预。未来需开展更大样本量的前瞻性研究以验证本研究结果。