Area under curves (AUC) as a measure of predictive strength for risk-prediction models based on different indicators^a.

a<p>The environmental model is based on consumption of salted fish and preserved vegetables, and cumulative amount of smoking. The family history of NPC model includes family history of NPC only. The epidemiological model combines both environmental and family history of NPC predictors. The genetic risk score model includes a score derived from seven SNPs identified in the Cantonese GWAS. The inclusive model integrates all data on epidemiological and genetic predictors.</p>b<p>χ² statistic and <i>P</i> value was calculated from the Hosmer–Lemeshow Goodness-of-Fit test, a model with χ² statistic <20 (<i>P</i>>0.01) is considered as a good calibration.</p>c<p>AUC of the models were compared with a nonparametric approach, and <i>P</i> value was obtained from the comparison of the inclusive model with the other models.</p

Associations between genetic variants, epidemiological risk factors and risk of nasopharyngeal carcinoma.

a<p>OR = odds ratio; CI = confidence interval. OR and 95% CI were derived from logistic regression, with adjustment for age, sex, education level, dialect, household type (rural/urban).</p>b<p>OR and 95% CI were derived using logistic regression adjusted for age, sex, education level, dialect, rural or urban household type, and all other variables listed in the table.</p>c<p><i>P</i> values for trend (two-sided) were derived from Cochran- Armitage trend tests.</p

Distribution of genetic risk score.

<p>Distribution of the seven SNPs-based genetic risk score in 1,387 NPC cases (black bars) and 1,459 controls (grey bars). Individual risk for NPC was calculated by weighting each risk allele with its corresponding risk coefficient, which was derived from logistic regression.</p

Receiver-operating characteristic (ROC) analysis.

<p>The areas under the ROC curves (AUC) as measures of predictive power for risk-assessment models based on environmental risk factors, family history of NPC, and genetic variants for NPC.</p

Reclassification of data for use in epidemiological and inclusive models^a.

a<p>NRI: net reclassification improvement; IDI: integrated discrimination index; Reclassification was calculated for strata of predicted risk of <0.2, 0.2 to 0.3, and ≥0.3.</p

Distribution of risk for NPC by genetic risk score (in quintiles).

<p>Risk of NPC (expressed as OR ±95% CI) was adjusted for age, sex, education level, dialect, residential area, family history of NPC, pack-years smoked, salted fish and preserved vegetables consumption. The boundaries for each genetic risk score quintile are shown on the <i>x</i>-axis.</p