Characteristics of included studies
Seventeen studies met inclusion criteria for the ADR outcome, collectively enrolling 15,242 patients.19-35 Twelve of these studies reported extractable PDR data suitable for pooling (Table 3).19-35 The included trials were published between 2024 and 2026, comprising four studies from 2024, seven from 2025, and six from 2026, reflecting the temporally restricted evidence base defined a priori for this synthesis. Study designs were predominantly parallel-group randomized controlled trials, with one quasi-randomized cluster design (Lagström 2025).21
| Study | Year | Total N | ADR CADe (events/N) | ADR Control (events/N) | ADR RR (95% CI) | PDR CADe (events/N) | PDR Control (events/N) | PDR RR (95% CI) | AI system |
|---|
| Park 202419 | 2024 | 805 | 153/437 | 103/368 | 1.25 (1.02–1.54) | 271/437 | 191/368 | 1.19 (1.06–1.35) | RetinaNet-based |
| Alali 202520 | 2025 | 102 | 24/51 | 19/51 | 1.26 (0.80–2.00) | 40/51 | 29/51 | 1.38 (1.04–1.82) | CAD EYE (Fujifilm) |
| Lagström 202521 | 2025 | 795 | 236/399 | 184/395 | 1.27 (1.11–1.45) | 279/400 | 222/395 | 1.24 (1.11–1.38) | GI Genius (Medtronic) |
| Schauer 202622 | 2026 | 776 | 243/383 | 225/393 | 1.11 (0.99–1.24) | 298/383 | 286/393 | 1.07 (0.99–1.16) | ENDO-AID (Olympus) |
| Seager 2024 (COLO-DETECT)23 | 2024 | 1966 | 555/980 | 477/986 | 1.17 (1.08–1.27) | — | — | — | GI Genius (Medtronic) |
| EAGLE 202524 | 2025 | 841 | 180/417 | 152/424 | 1.20 (1.02–1.42) | 251/417 | 225/424 | 1.13 (1.01–1.28) | CADDIEv1.4 (Odin Medical LTD) |
| Hsu 202625 | 2026 | 1356 | 395/675 | 363/681 | 1.10 (1.00–1.21) | — | — | — | aetherAI Endo |
| Thiruvengadam 202426 | 2024 | 1100 | 234/550 | 189/550 | 1.24 (1.06–1.44) | — | — | — | GI Genius (Medtronic) |
| Maas 2024 (DISCOVERY)27 | 2024 | 497 | 96/250 | 93/247 | 1.02 (0.81–1.28) | 138/250 | 127/247 | 1.07 (0.91–1.27) | DISCOVERY (PENTAX Medical) |
| Spada 2025 (ACCENDO-Colo)28 | 2025 | 1158 | 290/578 | 235/580 | 1.24 (1.09–1.41) | — | — | — | ENDO-AID OIP-1 (Olympus) |
| Yabuuchi 202529 | 2025 | 998 | 254/501 | 271/497 | 0.93 (0.83–1.05) | — | — | — | EndoBRAIN-AY E v1.2.0 (Cybernet Systems Corp) |
| Xu 202530 | 2025 | 390 | 78/195 | 77/195 | 1.01 (0.79–1.29) | 131/195 | 111/195 | 1.18 (1.01–1.38) | Custom-developed CADe Software |
| Jeon 202631 | 2026 | 998 | 260/497 | 181/501 | 1.45 (1.25–1.67) | 359/497 | 273/501 | 1.33 (1.20–1.46) | ENAD-DET-01 (Ainex Corporation) |
| Dos Santos 202532 | 2025 | 711 | 180/354 | 164/357 | 1.11 (0.95–1.29) | 240/354 | 225/357 | 1.08 (0.97–1.20) | CAD EYE (Fujifilm) |
| Spada 2026 (FIT-AI)33 | 2026 | 1009 | 342/506 | 301/503 | 1.13 (1.03–1.24) | 401/506 | 350/503 | 1.14 (1.06–1.23) | GI Genius (Medtronic) |
| Lux 2026 (EndoMind)34 | 2026 | 914 | 156/452 | 152/462 | 1.05 (0.87–1.26) | 243/452 | 252/462 | 0.99 (0.87–1.11) | EndoMind (Research -developed system, University Hospital Wurzburg Group) |
| Davila-Piñón 2026 (PolyDeep Advance 3)35 | 2026 | 827 | 250/411 | 240/416 | 1.05 (0.94–1.18) | 286/411 | 286/416 | 1.01 (0.92–1.11) | PolyDeep (Galicia Sur/University of Vigo research group) |
Risk-of-bias assessment using the Cochrane RoB 2 tool classified nine randomized trials as low risk and seven as raising some concerns; the quasi-randomized Lagström study was judged to have serious overall risk of bias using ROBINS-I. Among the randomized trials, concerns were most commonly attributable to the randomization process domain (Park 2024, Xu 2025, and Spada 2026b) or to deviations from intended interventions and missing outcome data (EAGLE 2025, Hsu 2026, Spada 2025/ACCENDO-Colo, Lux 2026/EndoMind). Several trials exhibited notable methodological features warranting mention: Lagström 2025 employed a cluster-randomized quasi-experimental design with an associated denominator imbalance between arms; Park 2024 showed an unequal arm-size allocation; Xu 2025 reported multiple baseline imbalances between groups; Dos Santos 2025 was conducted by a single endoscopist, limiting generalizability; Schauer 2026 was funded by the device manufacturer (Olympus America), which also provided the CADe equipment free of charge; ; and Spada 2026b (FIT-AI) reported comparatively weak allocation concealment. Two studies, Lux 2026 (EndoMind) and Davila-Piñón 2026 (PolyDeep Advance 3), evaluated not-for-profit CADe systems, distinguishing them from the predominantly commercially developed platforms assessed elsewhere in the pool.
Four studies retained for qualitative synthesis only (Codesido-Prado 2026,36 Chang 2026,37 Leggett 2026/DEEP2,38 Robles de la Osa 202639) were excluded from the quantitative synthesis because raw counts were unextractable or outcome-reporting formats were incompatible.
Risk-of-bias assessment
Risk of bias was assessed using the RoB 2 tool across five domains40: bias arising from the randomization process, bias due to deviations from intended interventions, bias due to missing outcome data, bias in measurement of the outcome, and bias in selection of the reported result. Judgments were made at the outcome level and categorized as low risk, some concerns, or high risk of bias according to the RoB 2 framework (Table 4).19,20,22-35
| Study | D1: Randomization process | D2: Deviations from intended interventions | D3: Missing outcome data | D4: Measurement of the outcome | D5: Selection of the reported result | Overall risk of bias |
|---|
| Park 202419 | Some concerns | Low risk | Some concerns | Low risk | Low risk | Some concerns |
| Alali 202520 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Schauer 202622 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Seager 2024 (COLO-DETECT)23 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| EAGLE 202524 | Low risk | Low risk | Some concerns | Low risk | Low risk | Some concerns |
| Hsu 202625 | Low risk | Low risk | Some concerns | Low risk | Low risk | Some concerns |
| Thiruvengadam 202426 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Maas 2024 (DISCOVERY)27 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Spada 2025 (ACCENDO-Colo)28 | Low risk | Some concerns | Some concerns | Low risk | Low risk | Some concerns |
| Yabuuchi 202529 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Xu 202530 | Some concerns | Low risk | Low risk | Low risk | Low risk | Some concerns |
| Jeon 202631 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Dos Santos 202532 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Spada 2026 (FIT-AI)33 | Some concerns | Low risk | Low risk | Low risk | Low risk | Some concerns |
| Lux 2026 (EndoMind)34 | Low risk | Some concerns | Low risk | Low risk | Low risk | Some concerns |
| Davila-Piñón 2026 (PolyDeep Advance 3)35 | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
Overall, the methodological quality of the included trials was considered acceptable. No trial was judged to be at overall high risk of bias based on the available information. However, several studies raised specific methodological concerns, principally related to post-randomization exclusions, quasi-randomized allocation, baseline imbalance, or allocation concealment.
Park et al.19 was judged to have some concerns, primarily because of post-randomization imbalance between study arms associated with differential withdrawal, particularly in the control group. Differential post-randomization withdrawals between study arms raised some concerns in the domain of missing outcome data, as the extent and imbalance of exclusions could potentially be related to the outcome.
Funding and manufacturer involvement were also considered as potential sources of bias. For Schauer et al.,22 the reported industry involvement was evaluated in relation to the RoB 2 domains, particularly the selection of the reported result and other aspects of trial conduct and reporting. No evidence was identified that industry involvement influenced the randomization process, deviations from intended interventions, outcome assessment, or selective reporting; therefore, industry sponsorship alone did not warrant upgrading the RoB 2 judgment.
Because Lagström et al.21 used quasi-randomized allocation based on alternating 2-week intervention periods rather than individual randomization, risk of bias for this study was assessed separately using the ROBINS-I tool (Table 5). For ADR, the study was judged to have serious overall risk of bias, primarily because the time-block allocation could introduce confounding by calendar period, center, endoscopist characteristics, and changes in patient case-mix over time. Additional moderate concerns related to post-allocation exclusions and incomplete outcome data. The measurement of ADR was considered at low risk of bias because adenoma status was confirmed histologically.
| Study | D1 Confounding | D2 Selection | D3 Classification | D4 Deviations | D5 Missing data | D6 Measurement | D7 Reported result | Overall |
|---|
| Lagström 202521 | Serious | Low | Low | Moderate | Moderate | Low | Low | Serious |
EAGLE and Hsu et al.25 were considered to have some concerns related principally to missing outcome data and post-randomization exclusions. In EAGLE, 973 participants were randomized, whereas 841 were included in the final analyzed population; although the exclusions were reported with specific reasons, the extent of post-randomization attrition warranted a cautious judgment. In the Hsu trial, 1,457 participants were randomized and 1,356 were included in the final analysis, leading to a similar concern regarding outcome completeness. EAGLE used block randomization with electronic allocation procedures and blinded pathological assessment, whereas the Hsu trial used a computer-generated 1:1 randomization sequence and intention-to-treat analysis.
Spada et al.28 (ACCENDO-Colo) 2025 was judged to have some concerns because of post-randomization exclusions and the open-label design. Although randomization was performed using a central computer-generated sequence, 70 of 1,228 randomized participants were subsequently excluded from the mITT analysis.
Xu et al.30 was judged to have some concerns because of multiple baseline imbalances between study groups. Spada et al.33 (FIT-AI) 2026 was also classified as having some concerns because of limitations in allocation concealment. Lux et al.34 was judged to have some concerns because endoscopists could not be blinded to CADe allocation. This limitation is inherent to CADe-assisted colonoscopy and was not considered sufficient to indicate high risk of bias by itself. Importantly, the Lux trial used centralized randomization and was conducted as a multicenter randomized controlled study.
The remaining trials were judged to have low overall risk of bias based on the available methodological information. In particular, the use of open-label designs was not automatically interpreted as high risk because blinding of endoscopists is generally infeasible in CADe-assisted colonoscopy. Where outcome ascertainment relied on histopathological confirmation, blinded pathological assessment further reduced the potential for bias in outcome classification.
Manufacturer involvement or industry-provided equipment was considered separately as a potential source of concern but was not, in the absence of evidence of influence on trial conduct, analysis, or reporting, sufficient by itself to warrant a higher RoB 2 judgment. Accordingly, the manufacturer-supported Schauer trial was not classified as having increased RoB 2 solely on the basis of industry involvement.
Overall, the risk-of-bias assessment indicated that the contemporary evidence base was predominantly of acceptable methodological quality, with some concerns concentrated in specific aspects of randomization, allocation concealment, post-randomization exclusions, baseline comparability, and unavoidable lack of blinding in procedural CADe trials.
Among the 17 trials included in the quantitative ADR analysis, 9 (52.9%) were judged to be at low overall risk of bias, 7 (41.2%) to have some concerns, and 1 (5.9%) to be at serious overall risk of bias. The latter was the quasi-randomized study by Lagström et al.,21 which was assessed separately using ROBINS-I because of its time-block allocation design. The main methodological concerns across the included studies related to quasi-randomized allocation and potential confounding, post-randomization exclusions or incomplete outcome data, baseline imbalances, limitations in allocation concealment, and the inability to blind endoscopists to CADe allocation.
Sensitivity analysis: leave-one-out
A leave-one-out sensitivity analysis was performed for both outcomes to assess the influence of individual studies on the pooled estimate and on observed heterogeneity.
The ADR pooled estimate proved robust in direction and approximate magnitude: exclusion of any single trial produced a pooled RR within the narrow range of 1.12–1.16, remaining statistically significant in every iteration. Excluding Yabuuchi 2025 or Jeon 2026 produced the largest reductions in I² (to 33.2% and 35.6%, respectively), but heterogeneity remained moderate in both cases and stayed at 53–57% following exclusion of every other individual trial. This indicates that the heterogeneity observed in the expanded ADR pool does not stem from a single outlying study but instead reflects broader, multi-source between-study variance.
Excluding Jeon 2026 produced the largest reduction in I² (from 63.4% to 44.5%), but heterogeneity remained moderate rather than being eliminated, and removal of any other individual trial left I² at 58–67%. This indicates that the heterogeneity in the PDR pooled estimate reflects distributed, multi-source variance across the evidence base rather than a single influential trial — consistent with the pattern observed for ADR.
As a post-hoc exploratory analysis addressing the cluster-based allocation design of Lagström et al., the sensitivity analysis doubled the variance of Lagström et al. to account for its quasi-randomized, cluster-based design; this left both pooled estimates essentially unchanged (ADR: RR 1.14, 95% CI 1.08–1.20, I² = 52.0%; PDR: RR 1.13, 95% CI 1.07–1.19, I² = 61.3%).