Negative predictive value of fecal immunochemical testing in significant bowel disease screening: a systematic review and meta-analysis

Objectives: General practitioners (GPs) must assess significant bowel disease (SBD) in patients with lower bowel symptoms during primary care. Studies have evaluated the efficacy of fecal immunochemical testing (FIT) for SBD screening. However, the effectiveness of FIT remains controversial. This study aimed to investigate the value of FIT in SBD screening. Methods: PubMed, the Cochrane Database, and EMBASE were systematically searched. Studies that estimated FIT values in screening for SBD among patients with lower bowel symptoms were included. Sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), diagnostic odds ratio (DOR), and negative predictive value (NPV) were calculated. Additionally, the pooled area under the summary receiver operating characteristic (SROC) curve was analyzed. Results: A total of 8615 patients with lower bowel symptoms who underwent FIT and colonoscopy to screen for SBD were enrolled and assessed in this meta-analysis; of these, 1226 patients were ultimately diagnosed with SBD. The pooled sensitivity, specificity, PLR, NLR, DOR, and NPV of FIT in SBD screening were 0.65 (95% CI: 0.50–0.78), 0.85 (95% CI: 0.72–0.92), 4.2 (95% CI: 2.60–6.90), 0.41 (95% CI: 0.29–0.58), 10 (95% CI: 6–17), and 0.90 (95% CI: 0.87–0.94), respectively. Besides, the pooled SROC was 0.82 (95% CI: 0.78–0.85). Conclusions: This study indicates that the FIT provides a favorable NPV for SBD screening and could be a valuable technique for GPs to rule out SBD in primary care. At the same time, GPs need to remain vigilant and refer patients to gastroenterologists when necessary.