Sir,Subha et al. in the past issue of “Annals of Indian Academy of Neurology” well-described the prevalence, patterns, and frequency of risk factors among young strokepatients in comparison to old ones and indicated valuable findings.[1] However, I would like to highlight concern regarding their study design. The definition of case-control comparison in a body of cross-sectional data seemed to be unfamiliar. They defined their case and control groups as those patients having definite stroke that occurred at less than 50 years and above 50 years of age, respectively, and investigated the differences among the risk factors of stroke between these two groups. Although the result obtained was discussed in a logical way, in my opinion it should be underlined that the odds ratio (OR) reported in chi-square test and then completed by logistic regression was not empowered enough as expected in a case-control setting and the interpretation of the results should be done with caution. Apart from this, the obvious disparity between the population of the two study groups can negatively affect the OR, which was explained before.[2]It is well-known that in case-control studies, study groups are defined by outcome. On the other hand, due to the backward design of such studies in comparison with most other studies, it usually confuses the researchers regarding the conduct of the study and interpretation of the data.[3] Thus, the comparison between two similar outcomes at the same time could never be interpreted as a case-control study.