Abstract
In the modern era, with high-throughput technology and large data size, associational studies are actively being generated. Some have statistical and clinical validity and utility, or at least have biologically plausible relationships, while others may not. Recently, the potential effect of birth month on lifetime disease risks was studied in a phenome-wide model. We evaluated the associations between birth month and 5 cardiovascular diseases in an independent dataset of 8,346 patients from Canada in 1977-2014. We compared the predictiveness of birth month vs. sex (or age) by various statistical measures, and also examined the event rate over birth months by sex. Hypertension and coronary heart disease were most prevalent in those who were born in January and April, respectively, as observed in the original paper. Other outcomes showed weak or opposite associations. Time-trends of blood pressures and of event rates by sex demonstrate inconsistent patterns, implying high randomness. As scientific importance/meaningfulness and clinical implications and practical usefulness can be different, readers would want to read the original and new papers together for more objective interpretations of the potential impacts of birth month on personal and public health.