Meta-análisis en R con el paquete metafor

Question

¿Cómo debo sintetizar el rma función de metafor para obtener resultados en el siguiente ejemplo real de un pequeño meta-análisis? (efecto aleatorio, estadística de resumen SMD)

study,      mean1, sd1,    n1,  mean2,  sd2,   n2

Foo2000,    0.78,  0.05,   20,  0.82,   0.07,  25    
Sun2003,    0.74,  0.08,   30,  0.72,   0.05,  19    
Pric2005,   0.75,  0.12,   20,  0.74,   0.09,  29    
Rota2008,   0.62,  0.05,   24,  0.66,   0.03,  24    
Pete2008,   0.68,  0.03,   10,  0.68,   0.02,  10

Answer 1

Cree un sistema de data.frame :

df <- structure(list(study = structure(c(1L, 5L, 3L, 4L, 2L), .Label = c("Foo2000", 
"Pete2008", "Pric2005", "Rota2008", "Sun2003"), class = "factor"), 
    mean1 = c(0.78, 0.74, 0.75, 0.62, 0.68), sd1 = c(0.05, 0.08, 
    0.12, 0.05, 0.03), n1 = c(20L, 30L, 20L, 24L, 10L), mean2 = c(0.82, 
    0.72, 0.74, 0.66, 0.68), sd2 = c(0.07, 0.05, 0.09, 0.03, 
    0.02), n2 = c(25L, 19L, 29L, 24L, 10L)), .Names = c("study", 
"mean1", "sd1", "n1", "mean2", "sd2", "n2"), class = "data.frame", row.names = c(NA, 
-5L))

Ejecutar el rma -función:

library(metafor)
rma(measure = "SMD", m1i = mean1, m2i = mean2, 
    sd1i = sd1, sd2i = sd2, n1i = n1, n2i = n2, 
    method = "REML", data = df)

Tenga en cuenta que rma asume (m1i-m2i) . Esto da como resultado el siguiente meta-análisis de modelo de efectos aleatorios univariante:

> rma(measure = "SMD", m1i = mean1, m2i = mean2, 
+     sd1i = sd1, sd2i = sd2, n1i = n1, n2i = n2, 
+     method = "REML", data = df)

Random-Effects Model (k = 5; tau^2 estimator: REML)

tau^2 (estimate of total amount of heterogeneity): 0.1951 (SE = 0.2127)
tau (sqrt of the estimate of total heterogeneity): 0.4416
I^2 (% of total variability due to heterogeneity): 65.61%
H^2 (total variability / within-study variance):   2.91

Test for Heterogeneity: 
Q(df = 4) = 11.8763, p-val = 0.0183

Model Results:

estimate       se     zval     pval    ci.lb    ci.ub          
 -0.2513   0.2456  -1.0233   0.3061  -0.7326   0.2300          

---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

Es posible que desee cambiar la estimación method Por ejemplo method = "DL" (pero yo me quedaría con REML ).