Table 3. Gender specific risk estimates for diabetes mellitus-associated thyroid cancer overall and within subgroups.
| N of studies | N of thyroid cancer cases | Summary RR (95% CI) a | p-heterogeneity | ||
| Women | |||||
| All studies | 11 | 1,542 | 1.24 (0.98–1.58) c | 0.11 | |
| Sensitivity analysis b | 9 | 1,244 | 1.38 (1.13–1.67) | 0.36 | |
| Study design b | Cohort studies | 7 | 929 | 1.45 (1.21–1.75) | 0.44 |
| Case-control studies | 2 | 315 | 0.69 (0.30–1.57) | 0.96 | |
| Geographical area b | High incidence regions | 6 | 1,055 | 1.50 (1.23–1.83) | 0.40 |
| Low incidence regions | 3 | 189 | 0.95 (0.60–1.50) | 0.81 | |
| Study quality b | Score ≥6 | 6 | 687 | 1.42 (1.08–1.85) | 0.26 |
| Score <6 | 3 | 557 | 1.20 (0.86–1.69) | 0.52 | |
| Men | |||||
| All studies | 7 | 506 | 1.15 (0.86–1.54) | 0.49 | |
| Sensitivity analysis b | 5 | 219 | 1.11 (0.80–1.53) | 0.92 | |
| Study design b | Cohort studies | 3 | 111 | 1.06 (0.74–1.50) | 0.81 |
| Case-control studies | 2 | 108 | 1.45 (0.62–3.38) | 0.81 | |
| Geographical area b | High incidence regions | 3 | 148 | 1.06 (0.73–1.53) | 0.71 |
| Low incidence regions | 2 | 71 | 1.30 (0.64–2.63) | 1.00 | |
| Study quality b | Score ≥6 | 3 | 123 | 1.10 (0.77–1.57) | 0.87 |
| Score <6 | 2 | 96 | 1.13 (0.51–2.51) | 0.42 |
a
All summary ORs/RRs (95% CIs) were calculated by the random-effect model
b
We excluded three studies using the risk estimates with SIRs ([14] and [32]) and the different definition of diabetes ([33] was included with IFG and IGT and [34] used quintile of glucose level)
c
Publication bias by Egger and Begg test (p<0.05).