male middle aged human 1,981 female 1,878 adult 1,788 Humans 1,783 Middle Aged 1,683 Male 1,660 Female 1,593 Adult 1,234 Article 1,155 aged 1,016 Aged 880 controlled study 880 major clinical study 801 young adult 611 Young Adult 572 adolescent 434 Adolescent 410 very elderly 359 procedures 349 retrospective study 332 Aged, 80 and over 328 clinical article 314 psychology 313 diagnostic imaging 282 cross-sectional study 268 cohort analysis 264 pathology 263 Retrospective Studies 253