Table 1b. Characteristics of included studies (N = 17).
| Study | Setting | Detection method | Smoker proportion | Routine vs opportunistic | Definition_SL | Definition_location | SL (%) | HP (%) | SSP (%) | TSA (%) |
| Liang 2012 | 3 | 1 | NA | 1 | WHO | – | 20.6 | – | – | – |
| Kahi 2011 | 2 | 1 | NA | 1 | WHO | a | 13.0 | – | – | – |
| Hetzel 2010 | 3 | 1 | NA | 1 | – | a | – | 11.7 | 0.6 | – |
| Abdeljaward 2015 | 2 | 1 | NA | 1 | WHO | a | 20.4 | – | 8.1 | 0.4 |
| Sanaka 2014 | 3 | 1 | NA | 1 | – | a | – | – | 1.8 | – |
| Ross 2015 | 2 | 1 | NA | 1 | – | – | – | – | 8.2 | – |
| Pyo 2017 | 3 | 1 | 28.4 | 1 | WHO | b | – | – | 0.5 | 0.6 |
| Min 2012 | 2 | 1 | NA | 1 | WHO | a | 11.9 | – | – | – |
| Kim 2014 | 3 | 1 | 59.7 1 65.1 2 | 1 | WHO | a | 15.1 | 14.7 | 0.5 | 0.1 |
| Lee 2013 | 3 | 1 | NA | 1 | WHO | a | 11.3 | – | – | – |
| Wijkerslooth 2013 | 2 | 1 | NA | 1 | WHO | a | 12.3 | – | – | – |
| Hazewinkel 2014 | 2 | 1 | NA | 1 | WHO | a | 27.2 | 23.8 | 4.8 | 0.1 |
| Grobbee 2017 | 2 | 1 | NA | 1 | – | – | – | 12.7 | 3.0 | – |
| Leung 2012 | 3 | 1 | NA | 1 | WHO | b | 21.4 | – | – | – |
| Chang 2017 | 3 | 1 | 20.1 | 1 | WHO | – | – | 1.9 | 1.4 | – |
| Buda 2012 | 2 | 1 | NA | 1 | WHO | – | – | 4.6 | 2.3 | 0.5 |
| Ijspeert 2016 | 2 | 1 | NA | 1 | WHO | a | 26.6 | – | 2.2 | 0.8 |
Setting: 1 = national screening program, 2 = multiple centers, 3 = single
hospital/site; Detection method: 1 = colonoscopy, 2 = Sigmoidoscopy; Routine vs. opportunistic: 1 = rountine,
2 = opportunistic; Screening vs. surveillance: 1 = Screening, 2 = Screening and surveillance.
NA, not available
WHO: Serrated lesions (SLs) were classified according to WHO criteria as hyperplastic polyps (HP), sessile serrated polyp (SSP) without cytologic dysplasia, SSP with cytologic dysplasia (SSP-CD), traditional serrated adenoma (TSA) with and without conventional dysplasia, and serrated polyps unclassified; a: The proximal colon was defined as proximal to the splenic flexure; b: The proximal colon was defined as proximal to transverse colon.
Adenoma group
Serrated lesions group