Analisis meta dalam R menggunakan paket metafor

10

Bagaimana seharusnya saya menyinkronkanrma fungsi dari paket metafor untuk mendapatkan hasil dalam contoh kehidupan nyata berikut dari meta-analisis kecil? (efek acak, ringkasan statistik 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
Staty Despair
sumber

Jawaban:

10

Buat yang benar 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))

Jalankan rma-fungsi:

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

Harap perhatikan bahwa rmaasumsi (m1i-m2i). Ini menghasilkan meta-analisis acak acak univariat model berikut:

> 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 

Anda mungkin ingin mengubah estimasi method, misalnya method = "DL"(tapi saya akan tetap dengan REML).

Bernd Weiss
sumber