Mune ongororo ichangobva kuitwa yakabudiswa muJAMA Network Open, vatsvakurudzi vanobva kuUnited States of America (US) vakaongorora kubatana pakati pechikwereti chekurapa uye hutano hwehuwandu hwevanhu muUS. Vakawana kuti chikwereti chekurapa chakabatana nehutano hwakanyanya uye kuwedzera kwekufa uye kufa kwevanhu. Chikwereti ichi chakabatana nemigumisiro yakaipa pane hutano, sekunonoka kwehutano, kusateerera, uye kuwedzera kwekudya uye kusachengeteka kwepamba.