%0 Journal Article %T Profile Likelihood Tests for Common Risk Ratios in Meta-Analysis Studies %A Chukiat Viwatwongkasem %A Khanokporn Donjdee %A Tantanut Poodphraw %J Open Journal of Statistics %P 915-930 %@ 2161-7198 %D 2018 %I Scientific Research Publishing %R 10.4236/ojs.2018.86061 %X It is well-known that the power of Cochran¡¯s Q test to assess the presence of heterogeneity among treatment effects in a clinical meta-analysis is low due to the small number of studies combined. Two modified tests (PL1, PL2) were proposed by replacing the profile maximum likelihood estimator (PMLE) into the variance formula of logarithm of risk ratio in the standard chi-square test statistic for testing the null common risk ratios across all k studies (i = 1, L, k). The simply naive test (SIM) as another comparative candidate has considerably arisen. The performance of tests in terms of type I error rate under the null hypothesis and power of test under the random effects hypothesis was done via a simulation plan with various combinations of significance levels, numbers of studies, sample sizes in treatment and control arms, and true risk ratios as effect sizes of interest. The results indicated that for moderate to large study sizes (¡Ý 16in combination with moderate to large sample sizes (\"\" ¡Ý 50), three tests (PL1, %K Profile Likelihood Test %K Cochran Q Test %K Meta-Analysis %K Heterogeneity %K Risk Ratios %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=89141