<p>Introduction:</p><p>The introduction is relatively well designed and the problematic of early initiation is address along the text. However, the references could be more up to date. It is important to understand if the inexistence of recent references is due to the inexistence of recent studies or due to a necessity of extend the parameters of the research.</p><p>Also, it all seems to be treat as exploratory as indeed there are an enormous amount of studies that address the problematic of early initiation, sex risk behavior and other health risk behaviors in adolescents and young adults. Therefore, for me, it would enrich the study the existence of theoretical predictions instead of research questions. Although it is comprehensible since the nature of the study, is not uncommon to predict relations upon variables.</p><p> </p><p>Method:</p><p>The method is extendedly described and I was very pleased to see a very good presentation of variables which is uncommon in nowadays studies.</p><p> </p><p>Results:</p><p>Results are well presented and all tables are informative. There is a good amount of information retrieved from data that seems to be important to further the knowledge in the field of study. Data analysis is well conducted.</p><p> </p><p>Discussion:</p><p>The discussion is undermined comparing to other parts of the manuscript. The results are poorly discussed although they comprise the pertinence of study effectively.</p><p>For instance, there are parts of the discussion that are not address in the introduction, as is “Thus, understanding what factors predict sexual behaviour might help design or reorient programs for this age group.  In what follows we will concentrate mostly on the results from the more robust models (#2 in Table 2).” – Prevention programs design was never introduced or explained as a general objective of this study.</p><p>The discussion has contours of conclusion. My suggestion is to clearly separate the discussion of results from the implications and limitations of the study, in order to make it more clear.</p><p> </p><p>Congratulations on your work.</p>