临床预测模型用到的统计学方法案例

hyc3140

A Student t-test (mean ± standard deviation) or Wilcoxon rank-sum test (median, P25 ~ P75) was performed for continuous variables. The categorical variables were compared by X2（chi-square test）.
The ICCs of quantitative data between the two observers was calculated.
Spearman coefficient was used for correlation analysis between quantitative parameters and CK19 status.
Multivariable logistic regression analyses were performed to identify the independent predictors of CK19-positive HCCs.
Akaike Information Criterion (AIC) was used to determine the optimal prediction model.
The receiver operator characteristic (ROC) curve was used to evaluate the performance of predicting the expression of CK19.
The comparison of different area under ROC (AUROC) curves was conducted by DeLong’s test.
In view of the imbalance between the patients with CK19-negative HCCs and those with CK19-positive HCCs, we further used the F1 score and the area under the precision-recall curve (AUPRC) to compare performances, as these methods are more informative in the evaluation of binary classifiers on imbalanced data sets.
Calibration curve was used to assess the consistency of nomogram.
Decision Curve Analysis (DCA) was used to evaluate the clinical utility of nomogram by quantifying the net benefit under different threshold probabilities.
R software (version 3.4.1) was used for analysis.
All differences were considered statistically significant with a p value of <0.05.

Zhao Y, Tan X, Chen J, Tan H, Huang H, Luo P, Liang Y, Jiang X. Preoperative prediction of cytokeratin-19 expression for hepatocellular carcinoma using T1 mapping on gadoxetic acid-enhanced MRI combined with diffusion-weighted imaging and clinical indicators. Front Oncol. 2023 Jan 19;12:1068231. doi: 10.3389/fonc.2022.1068231. PMID: 36741705; PMCID: PMC9893005.

hyc3140

Assessment of normality was performed using the Shapiro–Wilk test.

Variables with a normal distribution belonging to the FA and PT groups were compared using the independent t test whereas non-normally distributed data were compared using the Mann–Whitney U test.

Variables with a normal distribution were presented as mean ± standard deviation whereas those with a non-normal distribution were presented with median (range) values.

The comparison of the distribution of the BI-RADS categories belonging to the PT and FA groups were performed using the chi-square test.

The receiver operating characteristic (ROC) curve analysis was conducted to detect cut-off values with the best possible sensitivity and specificity.

A two-tailed p value smaller than 0.05 was considered to indicate a statistically significant difference.

All statistical analyses were performed using the R statistical software package (R studio, Vienna, Austria).