Aim: To examine the predictive factors of capsule endoscopy (CE) completion rate (CECR) including the effect of inpatient and outpatient status.
Methods: We identified 355 consecutive patients who completed CE at Rush University Medical Center between March 2003 and October 2005. Subjects for CE had either nothing by mouth or clear liquids for the afternoon and evening of the day before the procedure. CE exams were reviewed by two physicians who were unaware of the study hypotheses. After retrospective analysis, 21 cases were excluded due to capsule malfunction, prior gastric surgery, endoscopic capsule placement or insufficient data. Of the remaining 334 exams [264 out-patient (OP), 70 in-patient (IP)], CE indications, findings, location of the patients [IP vs OP and intensive care unit (ICU) vs general medical floor (GMF)] and gastrointestinal transit times were analyzed. Statistical analysis was completed using SPSS version 17 (Chicago, IL). Chi-square, t test or fisher exact-tests were used as appropriate. Multivariate logistic regression analysis was used to identify variables associated with incomplete CE exams.
Results: The mean age for the entire study population was 54.7 years. Sixty-one percent of the study population was female, and gender was not different between IPs vs OPs (P = 0.07). The overall incomplete CECR was 14% in our study. Overt obscure gastrointestinal bleeding (OGB) was significantly more common for the IP CE (P = 0.0001), while abdominal pain and assessment of IBD were more frequent indications for the OP CE exams (P = 0.002 and P = 0.01, respectively). Occult OGB was the most common indication and arteriovenous malformations were the most common finding both in the IPs and OPs. The capsule did not enter the small bowel (SB) in 6/70 IPs and 8/264 OPs (P = 0.04). The capsule never reached the cecum in 31.4% (22/70) of IP vs 9.5% (25/ 264) of OP examinations (P < 0.001). The mean gastric transit time (GTT) was delayed in IPs compared to OPs, 98.5 ± 139.5 min vs 60.4 ± 92.6 min (P = 0.008). Minimal SB transit time was significantly prolonged in the IP compared to the OP setting [IP = 275.1 ± 111.6 min vs OP = 244.0 ± 104.3 min (P = 0.037)]. CECR was also significantly higher in the subgroup of patients with OGB who had OP vs IP exams (95% vs 80% respectively, P = 0.001). The proportion of patients with incomplete exams was higher in the ICU (n = 7/13, 54%) as compared to the GMF (n = 15/57, 26%) (P = 0.05). There was only a single permanent SB retention case which was secondary to a previously unknown SB stricture, and the remaining incomplete SB exams were due to slow transit. Medications which affect gastrointestinal system motility were tested both individually and also in aggregate in univariate analysis in hospitalized patients (ICU and GMF) and were not predictive of incomplete capsule passage (P > 0.05). Patient location (IP vs OP) and GTT were independent predictors of incomplete CE exams (P < 0.001 and P = 0.008, respectively).
Conclusion: Incomplete CE is a multifactorial problem. Patient location and related factors such as severity of illness and sedentary status may contribute to incomplete exams.
Keywords: Capsule endoscopy; Completion rate; Hospitalization; Inpatient; Outpatient.