Female female 4,492 human 4,385 Humans 4,381 male 3,824 Male 3,768 adult 2,872 Adult 2,336 middle aged 1,720 Middle Aged 1,712 Article 1,605 controlled study 1,546 young adult 1,380 Young Adult 1,360 adolescent 1,226 Adolescent 1,198 major clinical study 1,140 aged 1,101 Aged 1,024 physiology 916 child 904 psychology 884 procedures 840 Child 811 article 705 diagnostic imaging 626 pathology 480 cross-sectional study 479 questionnaire 479 retrospective study 475