Table 2.
NOS score of included cohort studies.
| Score category | Score | Biasco | Rigatelli |
|---|---|---|---|
| Selection | |||
| Representativeness of the exposed cohort | 1 | 1 | 1 |
| Selection of the nonexposed cohort | 1 | 1 | 1 |
| Ascertainment of exposure | 1 | 1 | 1 |
| Demonstration that outcome of interest was not present at start of study | 1 | 1 | 1 |
| Comparability | |||
| Comparability of cohorts on the basis of the design or analysis | 2 | 1 | 1 |
| Outcome | |||
| Assessment of outcome | 1 | 1 | 1 |
| Was followed up long enough for outcomes to occur | 1 | 1 | 1 |
| Adequacy of follow-up of cohorts | 1 | 1 | 1 |
| Total score | 8 | 8 | |
Note: A study can be awarded a maximum of one star for each numbered item within the Selection and Exposure categories/Selection and Outcome categories. A maximum of two stars can be given for Comparability.