Table 2. Criteria for the evaluation of the methodological quality of the selected studies according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement22 .
| Section/topic | Lauridsen et al24 (2005) | Fourie and Robb14 (2009) | Wei et al15 (2013) | Cho et al25 (2016) | |
|---|---|---|---|---|---|
| 1 Title and abstract | Y | Y | Y | Y | |
| Introduction | 3 Background/rationale | Y | Y | Y | Y |
| 4 Objectives | Y | N | N | Y | |
| Methods | 5 Study design | Y | N | N | Y |
| 6 Participants | Y | Y | N | Y | |
| 7 Variables | Y | Y | Y | Y | |
| 8 Data sources/measurement | Y | Y | Y | Y | |
| 9 Bias | N | N | Y | Y | |
| 10 Study size | Y | N | N | Y | |
| 11 Quantitative variables | Y | N | N | Y | |
| 12 Statistical methods | Y | N | N | Y | |
| Results | 13 Participants | Y | N | N | Y |
| 14 Descriptive data | Y | N | Y | Y | |
| 15 Outcome data | Y | Y | Y | Y | |
| 16 Main results | Y | Y | Y | Y | |
| 17 Other analysis | Y | N | N | N | |
| Discussion | 18 Key results | Y | Y | Y | Y |
| 19 Limitations | N | N | N | Y | |
| 20 Interpretation | Y | Y | N | Y | |
| 21 Generalizability | N | N | N | Y | |
| Other information | 22 Funding | N | N | N | N |
| Total | 18/22–81% | 10/22–45% | 9/22–40% | 20/22–90% | |
| Final classification | A | C | C | A | |
Abbrreviations: Y, yes; N, no.