Studies on the Effectiveness of Intensive Versus Moderate Statin Therapy for Preventing Coronary Death or Myocardial Infarction
dat.cannon2006.RdResults from 4 trials examining the effectiveness of intensive (high dose) versus moderate (standard dose) statin therapy for preventing coronary death or myocardial infarction.
dat.cannon2006Format
The data frame contains the following columns:
| trial | character | trial name |
| pop | character | study population (post-ACS: post acute coronary syndrome; stable CAD: stable coronary artery disease) |
| nt | numeric | number of patients in the high dose group |
| nc | numeric | number of patients in the standard dose group |
| ep1t | numeric | number of events in the high dose group for end point 1: coronary death or non-fatal myocardial infarction |
| ep1c | numeric | number of events in the standard dose group for end point 1: coronary death or non-fatal myocardial infarction |
| ep2t | numeric | number of events in the high dose group for end point 2: coronary death or any cardiovascular event (MI, stroke, hospitalization for unstable angina, or revascularization) |
| ep2c | numeric | number of events in the standard dose group for end point 2: coronary death or any cardiovascular event (MI, stroke, hospitalization for unstable angina, or revascularization) |
| ep3t | numeric | number of events in the high dose group for end point 3: cardiovascular death |
| ep3c | numeric | number of events in the standard dose group for end point 3: cardiovascular death |
| ep4t | numeric | number of events in the high dose group for end point 4: non-cardiovascular death |
| ep4c | numeric | number of events in the standard dose group for end point 4: non-cardiovascular death |
| ep5t | numeric | number of events in the high dose group for end point 5: deaths (all-cause mortality) |
| ep5c | numeric | number of events in the standard dose group for end point 5: deaths (all-cause mortality) |
| ep6t | numeric | number of events in the high dose group for end point 6: stroke |
| ep6c | numeric | number of events in the standard dose group for end point 6: stroke |
Details
The data were obtained from Figures 2, 3, 4, and 5 in Cannon et al. (2006). The authors used the Mantel-Haenszel method for combining the results from the 4 trials. This approach is implemented in the rma.mh function.
Source
Cannon, C. P., Steinberg, B. A., Murphy, S. A., Mega, J. L., & Braunwald, E. (2006). Meta-analysis of cardiovascular outcomes trials comparing intensive versus moderate statin therapy. Journal of the American College of Cardiology, 48(3), 438–445. https://doi.org/10.1016/j.jacc.2006.04.070
Concepts
medicine, cardiology, odds ratios, Mantel-Haenszel method
Examples
### copy data into 'dat' and examine data
dat <- dat.cannon2006
dat
#> trial pop nt nc ep1t ep1c ep2t ep2c ep3t ep3c ep4t ep4c ep5t ep5c ep6t ep6c
#> 1 PROVE IT post-ACS 2099 2063 147 172 496 554 27 36 17 27 50 69 20 17
#> 2 A-TO-Z post-ACS 2265 2232 205 235 895 844 86 111 22 21 108 132 28 35
#> 3 TNT stable CAD 4995 5006 334 418 1405 1677 126 155 158 127 284 282 117 155
#> 4 IDEAL stable CAD 4439 4449 411 463 1176 1370 223 218 143 156 366 374 151 174
### load metafor package
library(metafor)
### meta-analysis of log odds ratios using the MH method for endpoint 1
res <- rma.mh(measure="OR", ai=ep1t, n1i=nt, ci=ep1c, n2i=nc, data=dat, slab=trial)
print(res, digits=2)
#>
#> Equal-Effects Model (k = 4)
#>
#> I^2 (total heterogeneity / total variability): 0.00%
#> H^2 (total variability / sampling variability): 0.38
#>
#> Test for Heterogeneity:
#> Q(df = 3) = 1.14, p-val = 0.77
#>
#> Model Results (log scale):
#>
#> estimate se zval pval ci.lb ci.ub
#> -0.18 0.04 -4.18 <.01 -0.26 -0.10
#>
#> Model Results (OR scale):
#>
#> estimate ci.lb ci.ub
#> 0.84 0.77 0.91
#>
#> Cochran-Mantel-Haenszel Test: CMH = 17.33, df = 1, p-val < 0.01
#> Tarone's Test for Heterogeneity: X^2 = 1.14, df = 3, p-val = 0.77
#>
### forest plot
forest(res, xlim=c(-.8,.8), atransf=exp, at=log(c(2/3, 1, 3/2)),
header=TRUE, top=2, cex=1.2, xlab="Odds Ratio")
mtext("(high dose better)", side=1, line=par("mgp")[1]-0.5, at=log(2/3), cex=1.2, font=3)
mtext("(standard dose better)", side=1, line=par("mgp")[1]-0.5, at=log(3/2), cex=1.2, font=3)
