^{ 1}Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea
^{ 2}Urological Biomedicine Research Institute, Soonchunhyang University Hospital, Seoul, Korea
^{ 3}Department of Nuclear Medicine, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Korea
^{ 4}BioMedical Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
^{ 5}Department of Internal Medicine, Jeju National University Hospital, Jeju National University School of Medicine, Jeju, Korea
©2019, Korean Society of Epidemiology
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■ Forest plot
· forest(sensitivity_logit, digits=3, rightcols=c(“effect”, “ci”), xlab=“Sensitivity”)
· specificity_logit <- metaprop(dta_shim$TN, dta_shim$TN+ dta_shim$FP, comb.fixed=FALSE, comb.random=TRUE, sm=“PLOGIT”, method.ci=“CP”, studlab=dta_shim$id, byvar=dta_shim$g)
·print(specificity_logit, digits=3)
■ Forest plot
· forest(specificity_logit, digits=3, rightcols=c(“effect”, “ci”), xlab=“Specificity”)
■ Forest plot
· forest(DOR_model, digits=3, rightcols=c(“effect”, “ci”), xlab =“Diagnostic Odds Ratio”)
■ Sensitivity and specificity correlation coefficient
Finally, to examine the correlation coefficient of sensitivity and specificity, additional variables are created for the current data as follows:
· dta_shim$sn <- dta_shim$TP/(dta_shim$TP+dta_shim$FN)
·dta_shim$sp <- dta_shim$TN/(dta_shim$FP+dta_shim$TN)
·dta_shim$logitsn <- log(dta_shim$sn/(1-dta_shim$sn))
·dta_shim$logitsp <- log(dta_shim$sp/(1-dta_shim$sp))
■ Meta regression analysis
The “mada” package does not provide functions for the meta regression analysis of the DTA. Therefore, the statistical significance of the moderating variable subgroup (Western European countries vs. other countries) is verified by performing meta regression analysis with the DOR as the effect size.
·library(meta)
·metareg(DOR_model, g, method.tau=“REML,” digits=3)
Summary statistics | Equation | Definition |
---|---|---|
Sn | TP/(TP+FN) | Proportion of persons who have positive test results to those with disease |
Sp | TN/(FP+TN) | Proportion of persons who have negative test result to those without disease |
PPV | TP/(TP+FP) | Proportion of persons with disease to those who have positive test result |
NPV | TN/(FN+TN) | Proportion of persons without disease to those who have negative test result |
LR+ | Sn/(1-Sp) | Ratio of the probability of a positive test result among those with disease to that of a positive test result among those without disease |
LR- | (1-Sn)/Sp | Ratio of the probability of a negative test result among those with disease to that of a negative test result among those without disease |
Accuracy of index test | (TP+TN)/(TP+FP+FN+TN) | The proportion of persons who are true positive and persons who are true negative among all subjects |
DOR | (TP*TN)/(FP*FN) | The ratio of the OR for a positive test result among persons with disease to that among persons without disease |
Id | TP | FP | FN | TN | g |
---|---|---|---|---|---|
Wiegmann | 21 | 1 | 9 | 104 | 1 |
Bouhanick | 49 | 21 | 7 | 110 | 1 |
Schwab | 24 | 5 | 3 | 31 | 1 |
Zelmanovitz | 39 | 6 | 5 | 48 | 0 |
Ahn | 23 | 9 | 7 | 41 | 0 |
Ng | 12 | 7 | 2 | 44 | 0 |
Gansevoort | 10 | 13 | 3 | 40 | 1 |
Incerti | 82 | 12 | 7 | 177 | 0 |
Sampaio | 99 | 45 | 21 | 128 | 0 |
Sn, sensitivity; Sp, specificity; PPV, positive predictive value; NPV, negative predictive value; LR+, positive likelihood ratio; LR-, negative likelihood ratio; DOR, diagnostic odds ratio; TP, true positive; FP, false positive; FN, false negative; TN, true negative; OR, odds ratio.
TP, true positive; FP, false positive; FN, false negative; TN, true negative; g, subgroup.