Results from 17 studies on the effectiveness of injected vaccines against cholera.

dat.graves2010

Format

The data frame contains the following columns:

studycharacterauthor/study name and publication year
ainumericnumber of cholera cases in the vaccinated group
n1inumericnumber of individuals in the vaccinated group
cinumericnumber of cholera cases in the placebo group
n2inumericnumber of individuals in the placebo group

Details

Cholera is an infection caused by certain strains of the bacterium Vibrio cholerae. When untreated, mortality rates can be as high as 50-60%. Proper sanitation practices are usually effective in preventing outbreaks, but a number of oral and injectable vaccines have also been developed. The Cochrane review by Graves et al. (2010) examined the effectiveness of injectable vaccines for preventing cholera cases and death. The present dataset includes results from 17 studies that reported the number of cholera cases in vaccinated and placebo/comparison groups up to 7 months after the treatment.

Source

Graves, P. M., Deeks, J. J., Demicheli, V., & Jefferson, T. (2010). Vaccines for preventing cholera: Killed whole cell or other subunit vaccines (injected). Cochrane Database of Systematic Reviews, 8, CD000974. https://doi.org/10.1002/14651858.CD000974.pub2

Examples

### copy data into 'dat' and examine data dat <- dat.graves2010 dat
#> study ai n1i ci n2i #> 1 Oseasohn 1965 8 6956 33 7103 #> 2 McCormack 1969 44 29939 35 9923 #> 3 Mosley 1970-i 32 11491 13 3810 #> 4 Mosley 1970-ii 2 11435 12 3810 #> 5 Taneja 1965 73 40326 27 10789 #> 6 PCC 1973b 72 82220 93 40620 #> 7 PCC 1973a-i 38 44500 23 11050 #> 8 PCC 1973a-ii 33 45750 22 11050 #> 9 PCC 1973a-iii 36 44450 23 11050 #> 10 PCC 1973a-iv 26 44700 22 11050 #> 11 Azurin 1965-i 110 145500 52 48934 #> 12 Azurin 1965-ii 92 148100 52 48933 #> 13 Azurin 1965-iii 71 143600 52 48933 #> 14 Pal 1980 13 101096 33 101030 #> 15 PCC 1968 54 268700 41 90900 #> 16 Saroso 1978-i 18 156300 19 79250 #> 17 Saroso 1978-ii 10 155600 18 79250
### analysis using the Mantel-Haenszel method rma.mh(measure="RR", ai=ai, n1i=n1i, ci=ci, n2i=n2i, data=dat, digits=2)
#> #> Fixed-Effects Model (k = 17) #> #> I^2 (total heterogeneity / total variability): 51.53% #> H^2 (total variability / sampling variability): 2.06 #> #> Test for Heterogeneity: #> Q(df = 16) = 33.01, p-val < .01 #> #> Model Results (log scale): #> #> estimate se zval pval ci.lb ci.ub #> -0.77 0.06 -13.51 <.01 -0.89 -0.66 #> #> Model Results (RR scale): #> #> estimate ci.lb ci.ub #> 0.46 0.41 0.52 #>