dat.spooner2002.RdResults from 17 trials, 11 studies in children and 6 studies in adults, reporting the maximum fall in the forced expiratory volume in 1 second (FEV$_1$) over the course of follow-up, expressed as a percentage.
dat.spooner2002The data frame contains the following columns:
| author | character | first author |
| year | character | year of publication |
| Ne | integer | number of participants in nedocromil sodium group |
| Me | numeric | maximum fall in the FEV$_1$ (nedocromil sodium) |
| Se | numeric | standard deviation (nedocromil sodium) |
| Nc | integer | number of participants in placebo group |
| Mc | numeric | maximum fall in the FEV$_1$ (placebo) |
| Sc | numeric | standard deviation (placebo) |
| agegroup | factor | age group (children or adults) |
Spooner et al. (2002) conducted a Cochrane review comparing nedocromil sodium (experimental treatment) with placebo (control) for preventing exercise-induced bronchoconstriction. Primary outcome was the maximum fall in the forced expiratory volume in 1 second (FEV$_1$) over the course of follow-up, expressed as a percentage. This outcome is available for 17 studies, 11 studies in children and 6 studies in adults. For each study, the mean value, standard deviation, and sample size are reported for both the experimental and control group. The authors conducted a random-effects meta-analysis with the mean difference as effect measure, i.e.\ mean value in the nedocromil sodium group minus mean value in the placebo group.
This data set is used as an example in Schwarzer et al. (2015).
Spooner, C., Saunders, L. D., & Rowe, B. H. (2002). Nedocromil sodium for preventing exercise‐induced bronchoconstriction. Cochrane Database of Systematic Reviews, 1, CD001183. https://doi.org/10.1002/14651858.CD001183
Schwarzer, G., Carpenter, J. R., & Rücker, G. (2015). Meta-analysis with R. Cham, Switzerland: Springer.
raw mean differences, subgroup analysis
### Show first five studies
head(dat.spooner2002, 5)
#> author year Ne Me Se Nc Mc Sc agegroup
#> 1 Boner 1988 13 13.54 13.85 13 20.77 21.46 Children
#> 2 Novembre 1994f 24 15.42 8.35 24 28.46 13.84 Children
#> 3 DeBenedictis 1994b 8 14.80 18.60 8 31.40 20.60 Children
#> 4 Novembre 1994s 19 11.00 12.40 19 26.10 14.90 Children
#> 5 DeBenedictis 1994a 17 14.40 11.10 17 27.40 17.30 Children
### Load meta package
suppressPackageStartupMessages(library("meta"))
### Use settings from RevMan5
oldset <- settings.meta("RevMan5")
### Conduct random effects meta-analysis with age subgroups
mc1 <- metacont(Ne, Me, Se, Nc, Mc, Sc,
data = dat.spooner2002, studlab = paste(author, year),
subgroup = agegroup, print.subgroup.name = FALSE,
label.e = "Nedocromil sodium", label.c = "Placebo",
common = FALSE)
mc1
#> Number of studies: k = 17
#> Number of observations: o = 480 (o.e = 240, o.c = 240)
#>
#> MD 95%-CI z p-value
#> Random effects model -15.64 [-18.14, -13.15] -12.30 < 0.0001
#>
#> Quantifying heterogeneity:
#> tau^2 = 2.437 [0.000, 40.900]; tau = 1.5612 [0.0000, 6.3953]
#> I^2 = 9% [0%, 45%]; H = 1.05 [1.00, 1.35]
#>
#> Test of heterogeneity:
#> Q d.f. p-value
#> 17.57 16 0.3496
#>
#> Results for subgroups (random effects model):
#> k MD 95%-CI tau^2 tau Q I^2
#> Children 11 -14.81 [-18.16, -11.45] 3.589 1.8944 11.25 11%
#> Adults 6 -16.89 [-20.81, -12.97] 3.127 1.7683 5.71 12%
#>
#> Test for subgroup differences (random effects model):
#> Q d.f. p-value
#> Between groups 0.63 1 0.4287
#>
#> Details on meta-analytical method:
#> - Inverse variance method
#> - DerSimonian-Laird estimator for tau^2
#> - Jackson method for confidence interval of tau^2 and tau
### Use previous settings
settings.meta(oldset)