Odds ratios (ORs) and 95% confidence intervals (CIs) were applied to assess a relationship between CYP1A1 MspI polymorphism and the HNC risk based on five applied genetic models by RevMan 5.3 software. 
RevMan
Other analyses (sensitivity analysis, meta-regression, and bias analysis) were performed by CMA 2.0 software. 
CMA
Trial sequential analysis (TSA) was done by TSA software (version 0.9.5.10 beta).  With regards to stable results and enough samples, the findings of the present meta-analysis recommended that there was an association between CYP1A1 MspI polymorphism and the HNC risk.
TSA