Criteria | Score |
---|---|
1. Representativeness of cases | Â |
 RA diagnosed according to acknowledged criteria. | 2 |
 Mentioned the diagnosed criteria but not specifically described. | 1 |
 Not Mentioned. | 0 |
2. Source of controls | Â |
 Population or community based | 3 |
 Hospital-based RA-free controls | 2 |
 Healthy volunteers without total description | 1 |
 RA-free controls with related diseases | 0.5 |
 Not described | 0 |
3. Sample size | Â |
  > 300 | 2 |
 200–300 | 1 |
  < 200 | 0 |
4. Quality control of genotyping methods | Â |
 Repetition of partial/total tested samples with a different method | 2 |
 Repetition of partial/total tested samples with the same method | 1 |
 Not described | 0 |
5. Hardy-Weinberg equilibrium (HWE) | Â |
 Hardy-Weinberg equilibrium in control subjects | 1 |
 Hardy-Weinberg disequilibrium in control subjects | 0 |