Table 1.
Criteria of Methodological Quality Assessment for Eligible Studies
| Criteria | Score |
|---|---|
| A. Representativeness of subjects | |
| Consecutive/randomly selected from population with clearly defined sampling frame | 2 |
| Consecutive/randomly selected from population without clearly defined sampling frame | 1 |
| Not described | 0 |
| B. Ascertainment of BMD measurement | |
| Clearly described standard method of measuring BMD, for example, using DXA, with details about calibration | 2 |
| Described standard method of measuring BMD, for example, using DXA, without details about calibration | 1 |
| Not described | 0 |
| C. Ascertainment of IL-6 genotype | |
| Genotyping done under blind conditions | 1 |
| Unblinded or not mentioned | 0 |
| D. Test for HWE | |
| HWE in study group | 2 |
| Hardy–Weinberg disequilibrium in study group | 1 |
| Insufficient data for test | 0 |
| E. Assessment of association | |
| Assessed association between genotypes and BMD with appropriate statistic and adjusting confounders | 2 |
| Assessed association between genotypes and BMD with appropriate statistic without adjusting confounders | 1 |
| Inappropriate statistic used | 0 |
| Total | 9 |
IL-6, interleukin-6; BMD, bone mineral density; DXA, dual-energy X-ray absorptiometry; HWE, Hardy–Weinberg equilibrium.