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) |
| order | numeric | order of studies in Table 1.1 in the Cochrane review |
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.
medicine, pulmonology, raw mean differences, subgroup analysis
### Show first five studies
head(dat.spooner2002, 5)
#> author year Ne Me Se Nc Mc Sc agegroup order
#> 1 Boner 1988 13 13.54 13.85 13 20.77 21.46 Children 1
#> 2 Boner 1989 20 15.70 13.10 20 22.70 16.47 Children 7
#> 3 Chudry 1987 12 21.30 13.10 12 39.70 12.90 Children 9
#> 4 Comis 1993 12 14.50 12.20 12 31.30 15.10 Children 10
#> 5 Debelic 1986 12 29.83 15.95 12 48.08 15.08 Children 11
### 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 (with 95%-CIs):
#> 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 of meta-analysis methods:
#> - Inverse variance method
#> - DerSimonian-Laird estimator for tau^2
#> - Jackson method for confidence interval of tau^2 and tau
#> - Calculation of I^2 based on Q
### Use previous settings
settings.meta(oldset)