TABLE 2.
Quantitative synthesis of the eligible meta-analyses of multiple risk factors for cervical cancer (Liaoning, China. 2021).
| Risk factor (reference) | No. of cases/participants | Summary relative risk (95% CI) | Random p value b | Fixed P value c | ||
|---|---|---|---|---|---|---|
| Random effects | Fixed effects | Largest study a | ||||
| Life style | ||||||
| Past smokers | 316/1363 | 0.87 (0.63–1.22) | 0.87 (0.63–1.22) | 0.75 (0.46–1.20) | 0.432 | 0.432 |
| Current smokers | 352/1565 | 0.84 (0.53–1.33) | 0.82 (0.60–1.12) | 0.82 (0.56–1.21) | 0.461 | 0.213 |
| Past smokers | 1658/2705 | 1.07 (0.61–1.87) | 0.94 (0.70–1.27) | 0.70 (0.47–1.03) | 0.825 | 0.705 |
| Current smokers | 1978/3191 | 1.57 (1.10–2.24) | 1.47 (1.15–1.88) | 1.26 (0.93–1.71) | 0.014 | 0.002 |
| Past smokers | 1417/15292 | 0.92 (0.75–1.14) | 0.92 (0.75–1.14) | 0.75 (0.53–1.07) | 0.447 | 0.447 |
| Current smokers | 1417/15292 | 0.90 (0.72–1.12) | 0.90 (0.75–1.08) | 0.81 (0.58–1.13) | 0.336 | 0.263 |
| Overweight | 2557/5371295 | 1.10 (0.97–1.25) | 1.10 (1.04–1.17) | 1.10 (1.03–1.17) | 0.146 | 0.002 |
| Obesity | 2557/5371295 | 1.45 (1.15–1.83) | 1.28 (1.15–1.42) | 1.21 (1.06–1.37) | 0.001 | 3.634 × 10−6 |
| Smoking | 1316/231002 | 2.10 (1.60–2.77) | 1.92 (1.68–2.20) | 1.57 (1.30–1.89) | 1.274 × 10−7 | 6.226 × 10−22 |
| Virus, microorganism, and parasite | ||||||
| HPV and HPV16 | 217/466 | 16.55 (8.22–33.33) | 16.55 (8.22–33.33) | 17.00 (6.80–44.00) | 3.861 × 10−15 | 3.861 × 10−15 |
| 260/763 | 3.68 (2.01–6.75) | 3.26 (2.15–4.94) | 3.20 (1.70–6.20) | 2.389 × 10−5 | 2.383 × 10−8 | |
| Herpes simplex type 2 | 3337/10047 | 1.21 (1.04–1.41) | 1.21 (1.04–1.41) | 1.10 (0.80–1.40) | 0.015 | 0.015 |
| HPV16 A4/Asian variants | 449/565 | 2.81 (1.44–5.51) | 2.67 (1.89–3.76) | 1.72 (1.04–2.85) | 0.003 | 2.029 × 10−8 |
| Chlamydia trachomatis infection | 832/4305 | 2.21 (1.62–3.03) | 2.22 (1.88–2.61) | 2.21 (1.84–2.65) | 6.427 × 10−7 | 2.625 × 10−21 |
| 3459/7494 | 2.19 (1.74–2.74) | 2.19 (1.95–2.45) | 2.44 (2.06–2.89) | 1.028 × 10−11 | 2.047 × 10−41 | |
| Coinfection of HPV and Chlamydia trachomatis | 1086/4608 | 4.37 (2.75–6.96) | 3.75 (2.92–4.82) | 3.23 (2.39–4.35) | 4.593 × 10−10 | 6.104 × 10−25 |
| Chlamydia trachomatis infection | 3198/8618 | 2.09 (1.79–2.44) | 2.21 (1.99–2.45) | 2.55 (2.15–3.03) | 6.866 × 10−21 | 3.973 × 10−51 |
| 329/2162 | 1.60 (1.19–2.14) | 1.60 (1.19–2.14) | 1.46 (0.96–2.23) | 0.002 | 0.002 | |
| Chlamydia trachomatis infection (serum) | 3528/10421 | 2.15 (1.83–2.53) | 2.19 (2.00–2.41) | 2.44 (2.06–2.89) | 8.143 × 10−21 | 2.736 × 10−59 |
| Epstein-Barr virus | 398/1062 | 4.00 (1.89–8.50) | 2.94 (2.07–4.16) | 0.20 (0.08–0.48) | 3.050 × 10−4 | 1.311 × 10−9 |
| Cervicovaginal lactobacilli | 23/111 | 0.16 (0.05–0.51) | 0.16 (0.05–0.51) | 0.18 (0.04–0.78) | 0.002 | 0.002 |
| Reproductive factors | ||||||
| In vitro fertilization | 174/40524 | 1.07 (0.45–2.55) | 0.64 (0.55–0.74) | 0.61 (0.52–0.71) | 0.871 | 5.010 × 10−9 |
| Intrauterine device use | 4945/12482 | 0.64 (0.53–0.77) | 0.70 (0.63–0.79) | 0.89 (0.73–1.08) | 1.906 × 10−6 | 5.409 × 10−9 |
| Oral contraceptives use | 2654/33389 | 1.70 (1.18–2.44) | 1.42 (1.25–1.62) | 1.34 (1.16–1.55) | 0.004 | 1.311 × 10−7 |
| 651/5660 | 1.77 (1.40–2.24) | 1.77 (1.40–2.24) | 1.60 (1.20–2.13) | 1.625 × 10−6 | 1.625 × 10−6 | |
| 3331/22205 | 1.29 (1.18–1.42) | 1.29 (1.18–1.42) | 1.31 (1.19–1.44) | 2.436 × 10−8 | 2.436 × 10−8 | |
| Oral contraceptives >10 years | 154/308226 | 2.24 (1.45–3.48) | 2.24 (1.45–3.48) | 2.93 (1.44–5.96) | 3.125 × 10−4 | 3.125 × 10−4 |
| Diseases | ||||||
| Endometriosis | 203/192501 | 0.67 (0.54–0.84) | 0.67 (0.54–0.84) | 0.71 (0.53–0.94) | 4.398 × 10−4 | 4.398 × 10−4 |
| Gestational diabetes mellitus | 1308/1163875 | 1.02 (0.81–1.29) | 1.02 (0.81–1.29) | 0.90 (0.65–1.26) | 0.843 | 0.843 |
| Nutrients and their levels | ||||||
| Total vitamin A intake | 3418/10478 | 0.59 (0.49–0.72) | 0.62 (0.57–0.68) | 0.95 (0.74–1.22) | 1.750 × 10−7 | 8.062 × 10−27 |
| Blood vitamin A levels (retinol) | 236/707 | 1.14 (0.83–1.57) | 1.14 (0.83–1.57) | 1.14 (0.78–1.66) | 0.422 | 0.422 |
| Blood vitamin A levels (carotene) | 474/1504 | 0.48 (0.30–0.76) | 0.57 (0.45–0.71) | 0.79 (0.54–1.14) | 0.002 | 1.495 × 10−6 |
| Retinol intake | 1078/3227 | 0.80 (0.64–1.00) | 0.85 (0.73–0.99) | 0.95 (0.74–1.22) | 0.048 | 0.042 |
| Carotene intake | 1244/4053 | 0.51 (0.35–0.74) | 0.48 (0.42–0.55) | 0.62 (0.47–0.80) | 3.150 × 10−4 | 1.446 × 10−23 |
| Carotenoid intake | 603/1754 | 0.60 (0.43–0.84) | 0.60 (0.49–0.74) | 0.60 (0.46–0.78) | 0.003 | 2.029 × 10−6 |
| Retinol intake | 371/761 | 0.83 (0.62–1.10) | 0.83 (0.62–1.10) | 0.82 (0.56–1.19) | 0.193 | 0.193 |
| Carotene intake | 434/895 | 0.37 (0.18–0.73) | 0.29 (0.22–0.38) | 0.21 (0.15–0.30) | 0.004 | 1.657 × 10−18 |
| Serum Selenium levels | 353/1206 | 0.55 (0.42–0.73) | 0.55 (0.42–0.73) | 0.58 (0.37–0.91) | 2.215 × 10−5 | 2.215 × 10−5 |
| Vitamin E | 1321/4177 | 0.53 (0.39–0.73) | 0.55 (0.48–0.63) | 0.48 (0.38–0.61) | 7.325 × 10−5 | 9.279 × 10−18 |
Abbreviation: CI, confidence interval; HPV, human papillomavirus.
a
Relative risk and 95% confidence interval of largest study (smallest SE) in each meta-analysis.
b
p value of summary random effects estimate.
c
p value of summary fixed effects estimate.
All statistical tests two sided.