Calculating Ratio of Means (ROM) and Confidence Interval

Calculating Ratio of Means (ROM) and Confidence Interval
using the means and standard deviations of two groups[1].
Group1: Sample size (SS1) Mean (M1) SD (SD1)
Group2: Sample size (SS2) Mean (M2) SD (SD2)
   Confidence Level

Result ln(ROM) Standard error
ROM: Confidence interval    Lower limit    Upper limit

Formula $$ln(ROM)=log(\frac{M_1}{M_2}) $$ $$S.E.[ln(ROM)]=\sqrt{\frac{1}{SS_1}*(\frac{SD_1}{M_1})^2+\frac{1}{SS_2}*(\frac{SD_2}{M_2})^2}$$

Notes:
When combining ROM with relative effect measures (such as OR/RR), the exposure should be binary (e.g., presence or absence of exposure), as differences in units of study factors may impact the estimated value.

Reference:

[1] Friedrich JO, Adhikari NK, Beyene J. Ratio of means for analyzing continuous outcomes in meta-analysis performed as well as mean difference methods. J Clin Epidemiol. 2011;64(5):556-564. doi:10.1016/j.jclinepi.2010.09.016.
[2] Friedrich, J.O., Adhikari, N.K. & Beyene, J. The ratio of means method as an alternative to mean differences for analyzing continuous outcome variables in meta-analysis: A simulation study. BMC Med Res Methodol 8, 32 (2008).