A pooled analysis to evaluate results of capsule endoscopy trials

Capsule endoscopy is a new tool in the evaluation of the small intestine. To speed evaluation and acceptance of this technology, the manufacturer (Given Imaging Ltd, Yoqneam, Israel) funded several trials. The data from these trials were collected at a central repository using a standardized reporting tool. Presentation of this data to the US Food and Drug Administration (FDA) in July 2003 led to the removal of the adjunctive term with regard to indication for capsule endoscopy, recognizing that the method is of independent importance for evaluating the small bowel. The aim of the present study was to combine the data from several capsule trials to help determine the yield and miss rate of capsule endoscopy for different diseases, compared with alternative diagnostic modalities.

Capsule studies were identified from a master database of funded studies. Studies were included in the pooled analysis if they reported a prospective comparison with another modality for evaluation of the small intestine.

32 studies with a total of 691 patients were found in the master database, of which 24 studies, representing 530 patients, met inclusion criteria and were entered into the pooled analysis. Prior to study entry, patients had undergone a mean of 6.77 diagnostic procedures, without findings. Of these 24 studies, 14 (involving 310 patients) were categorized as "bleeding" studies, and 10 studies (220 patients) as "nonbleeding small-bowel disorders" studies. The comparison procedure was push enteroscopy in 300 patients (in 45 for nonbleeding disorders), small-bowel series in 140 patients (in 125 for non-bleeding disorders), and colonoscopy with ileoscopy in 90 patients (50 for nonbleeding disorders). Overall analysis per patient showed new findings from capsule endoscopy in 50 % of patients; 17 % had new findings from the comparison method; in 22 % there were similar findings; and in 11 % there were no findings. A total of 1349 instances of disease were identified in the 530 examinations. Capsule endoscopy solely detected 87 % of the disease instances, while the comparison method solely detected 13 %. The yield for push enteroscopy alone was 14.8 %, for small-bowel series it was 9.9 %, and for colonoscopy it was 13.2 %. Capsule endoscopy missed 146 disease instances for a miss rate of 10 %; 989 were missed by the comparison methods for a miss rate of 73 %; and 214 were detected by both methods.

Capsule endoscopy is the state of the art method for noninvasive detection of small-bowel disease.