human 206 Humans 187 female 156 male 156 adult 133 Female 128 Male 127 Article 119 severity of illness index 114 Severity of Illness Index 113 middle aged 95 Middle Aged 90 Adult 86 controlled study 80 major clinical study 78 aged 72 Aged 57 disease severity 53 Illness & addiction: social aspects 49 adolescent 47 complication 45 COVID-19 44 young adult 44 Adolescent 43 Young Adult 40 cross-sectional study 37 psychology 37 coronavirus disease 2019 36 History of medicine 35 Cross-Sectional Studies 34