BACKGROUND: In contemporary studies, @entity49 is three times more common in adult @entity1 than in @entity1 . AIM: To study the change in sex ratio over time in @entity49 . SUMMARY OF REVIEW: We systematically reviewed the literature. Any type of study with at least 40 @entity1 with @entity49 that reported sex ratio was eligible. We ranked studies according to the year halfway the period of @entity1 recruitment. Pediatric studies were analyzed separately. Out of 6068 publications identified by our search, 112 studies (23,638 @entity1 ), published between 1966 and 2014, were included. The proportion of @entity1 among @entity1 with @entity49 significantly increased over time from a median of 54.8% in studies prior to 1981 to 69.8% after 2001 (p   =   0.002). There was a significant correlation between time of the study and proportion of @entity1 (Pearson's correlation coefficient 0.25, p   =   0.01). Oral contraceptive use among @entity1 with @entity49 also increased over time (Pearson's correlation coefficient 0.29, p   =   0.01). In contrast, the percentage of pregnancy-related cases remained stable (Pearson's correlation coefficient 0.04, p   =   0.77). Among 1702 @entity1 from pediatric studies, 39% were female and there was no correlation between sex ratio and time of the study (Pearson's correlation coefficient -0.42, p   =   0.14). CONCLUSIONS: In adult @entity1 with @entity49 , there is a shift in sex ratio over time with an increase in the proportion of @entity1 , whereas this is not observed in pediatric populations. A possible explanation for this phenomenon is an increase over time in the use of oral contraceptives by adult @entity1 .

Sex differences in XXXX : A systematic analysis of a shift over time.

@entity1 :: ('9606', 'Species') :: ['women', 'patients', 'patient', 'men'] @entity49 :: ('MESH:D019851', 'Disease') :: ['cerebral venous thrombosis']
@entity49 :: (MESH:D019851,Disease) :: ['cerebral venous thrombosis']
