Table 1.
Characteristics of included articles.
| First Author, Year of Publication | Country | Study Type | Study Sample (n) | Condition | Use of Control | Study Aims Pertaining to NLR | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Differentiate Diagnoses | Differentiate Clinical Activity | Differentiate Endoscopic Activity | Predict Treatment Response | Predict Other Clinical Outcomes | Generate Optimal Cutpoint | Association with Other Biomarkers | ||||||
| AbediManesh, 2011 | Iran | Uncontrolled, non-randomized trial | 43 | UC | No | X | X | |||||
| Abotaga, 2009 | USA | Retrospective cohort | 62 | UC | No | X | ||||||
| Acarturk, 2015 | Turkey | Retrospective case-control | 83 | UC, CD | Yes | X | X | X | X | |||
| Ahmad, 2015 | Iraq | Prospective case-control | 90 | UC, CD | Yes | X | ||||||
| Akpinar, 2018 | Turkey | Retrospective cross-sectional | 313 | UC | Yes | X | X | X | ||||
| Andrew, 2020 | Australia | Retrospective cohort | 72 | UC | No | X | X | |||||
| Argeny, 2018 | Austria | Retrospective cohort | 373 | CD | No | X | ||||||
| Ben Jeddi, 2019 | Tunisia | Retrospective cohort | 74 | CD | No | X | X | |||||
| Ben Mustapha, 2015 | Tunisia | Prospective case-control | 47 | CD | Yes | X | X | |||||
| Bertani, 2019 | Italy | Retrospective cohort | 46 | UC | No | X | X | X | X | |||
| Bertani, 2020 | Italy | Prospective cohort | 88 | UC | No | X | X | X | X | X | ||
| BouJaoude, 2018 | France/ Lebanon | Prospective case-control | 116 | CD | Yes | X | X | X | ||||
| Celikbilek, 2013 | Turkey | Prospective case-control | 54 | UC | No | X | X | X | ||||
| Chalmers, 2017 | Scotland | Prospective case-control | 182 | IBD | Yes | X | X | |||||
| Chen, 2018 | China | Retrospective case-control | 120 | CD | Yes | X | X | |||||
| Chen, 2020 | China | Retrospective cohort | 876 | UC, CD | Yes | X | X | |||||
| Cherfane, 2013 | USA | Retrospective cohort | 185 | UC | Yes | X | X | X | X | |||
| Con, 2021 | Australia | Retrospective cohort | 94 | UC | No | X | X | |||||
| Crispino, 2021 | Italy | Retrospective cohort | 107 | CD | No | X | X | X | ||||
| Demir, 2015 | Turkey | Retrospective cohort | 211 | UC | Yes | X | X | X | X | |||
| Dong, 2019 | China | Prospective case-control | 104 | UC | No | X | X | X | X | X | ||
| Dorobăţ, 2018 | Romania | Retrospective cohort | 63 | UC | No | X | ||||||
| El-Sadek, 2019 | Egypt | Retrospective cohort | 27 | UC | No | X | X | X | ||||
| Eraldemir, 2014 | Turkey | Prospective case-control | 65 | UC | Yes | X | X | |||||
| Eraldemir, 2016 | Turkey | Prospective case-control | 87 | CD | Yes | X | X | X | X | |||
| Feng, 2017 | China | Retrospective case-control | 206 | CD | Yes | X | X | X | ||||
| Fidan, 2017 | Turkey | Retrospective cohort | 67 | UC | No | X | X | X | ||||
| Fleshner, 2019 | USA | Prospective cohort | No data | UC | No | X | ||||||
| Gao, 2015 | China | Prospective case-control | 110 | CD | Yes | X | X | X | X | |||
| Gao, 2020 | China | Retrospective cohort | 54 | CD | No | X | X | |||||
| Gold, 2020 | USA | Retrospective cohort | 107 | UC, CD | No | X | ||||||
| Gur, 2018 | Turkey | Retrospective cohort | 43 | CD | No | X | ||||||
| Gur, 2020 | Turkey | Retrospective case-control | 104 | CD | Yes | X | ||||||
| Guthrie, 2013 | Scotland | Retrospective case-control | 57 | IBD | Yes | X | ||||||
| Hanafy, 2018 | Egypt | Prospective case-control | 168 | UC | Yes | X | X | X | X | |||
| Hanai, 2004 | Japan | Prospective case-control | 100 | UC | Yes | X | X | |||||
| Jardak, 2018 | Tunisia | Retrospective cohort | 87 | UC | No | X | ||||||
| Jeong, 2018 | South Korea | Retrospective case-control | 174 | IBD | Yes | X | X | X | X | |||
| Jeong, 2021 | South Korea | Retrospective case-control | 144 | UC | Yes | X | X | X | ||||
| Kang, 2017 | China | Retrospective cohort | 108 | CD | No | X | X | X | ||||
| Khoury, 2019 | Israel | Retrospective case-control | 436 | CD | Yes | X | X | |||||
| Messner, 2016 | Austria | Retrospective cohort | 206 | IBD | No | X | ||||||
| Michalak, 2019 | Poland | Prospective case-control | 112 | UC | Yes | X | X | |||||
| Nassri, 2020 | USA | Retrospective cohort | No data | CD | No | X | ||||||
| Ndulue, 2019 | USA | Retrospective case-control | 4739 | IBD | Yes | X | ||||||
| Nishida, 2017 | Japan | Retrospective cohort | 59 | UC | No | X | X | X | ||||
| Nishida, 2019 | Japan | Retrospective cohort | 45 | UC | No | X | X | |||||
| Nishida, 2020 | Japan | Retrospective cohort | 49 | UC | No | X | X | |||||
| Okba, 2019 | Egypt | Prospective case-control | 80 | UC | Yes | X | X | X | X | X | ||
| Ovidiu, 2017 | Romania | Retrospective cohort | 86 | UC | No | X | ||||||
| Parisi, 2013 | Belgium | Retrospective cross-sectional | 139 | IBD | No | X | ||||||
| Posul, 2015 | Turkey | Prospective cohort | 49 | UC | No | X | X | |||||
| Ryan, 2019 | USA | Uncontrolled, non-randomized trial | 9 | IBD | No | X | ||||||
| Stefanidis, 2015 | Greece | Retrospective cohort | 35 | IBD | No | X | ||||||
| Torun, 2012 | Turkey | Retrospective case-control | 255 | UC | Yes | X | X | X | X | |||
| Wlodarczyk, 2015 | Poland | Retrospective case-control | 45 | CD | No | X | X | |||||
| Xu, 2019 | China | Prospective cohort | 214 | UC, CD | No | X | X | |||||
| Yamamoto-Furusho, 2020 | Japan | Retrospective cohort | 158 | UC | No | X | X | X | X | |||
| Yarur, 2011 | USA | Retrospective cohort | 68 | IBD | No | X | ||||||
| Zhang, 2017 | China | Prospective case-control | 34 | UC, CD | Yes | X | X | X | ||||
| Zhang, 2021 | China | Retrospective case-control | 344 | UC | Yes | X | X | X | ||||
| Zhou, 2021 | China | Retrospective case-control | 112 | CD | Yes | X | X | X | ||||
NLR: Neutrophil–lymphocyte ratio; UC: ulcerative colitis; CD: Crohn’s disease; IBD: inflammatory bowel disease; USA: United States of America. “X” denotes the aims identified in studies pertaining to NLR.