Characteristics of simulation models.

*. The simulation model consists of 5 covariates, each with OR of 1.5. In analysis, we assume that only the last two covariates are considered.$. In analysis, a more stringent threshold (10−4) is used for significance, compared to other simulation models (.05).n: number of cases, assuming case:control ratio of 1∶1; RAF: risk allele frequency; ORg: odds ratio for risk allele; ORz: odds ratios for covariates; corr: correlation coefficient between causal variant and the last covariate; αmax: variation in sample proportions (see “Methods”). Model 1–4 were simulated under the null hypothesis of no association; and model 5–12 were under the alternative hypothesis. Model 1 and 5 were treated as baseline models, and changes of parameters in other models were highlighted.Characteristics of simulation models.