| A. Representativeness of cases |
|
| Selected from population or hospital |
2 |
| Selected from any cardiovascular diseases service |
1 |
| Selected without clearly defined inclusion/exclusion criteria |
0 |
| B. Credibility of controls |
|
| Population-based |
3 |
| Blood donors or volunteers |
2 |
| Hospital-based |
1 |
| Not described |
0 |
| C. Ascertainment of heart failure |
|
| Two doctors confirmed |
2 |
| Diagnosis of heart failure by patient medical record |
1 |
| Not described |
0 |
| D. Genotyping examination |
|
| Genotyping done under blinded condition |
1 |
| Not mentioned |
0 |
| E. Hardy-Weinberg equilibrium |
|
| Equilibrium in controls |
2 |
| Disequilibrium in controls |
1 |
| No checked |
0 |
| F. Association assessment |
|
| Assess association between genotypes and heart failure with appropriate statistics |
2 |
| Assess association between genotypes and colorectal cancer with logistic regression |
1 |
| Inappropriate statistics used |
0 |
