CPR knowledge and resuscitation self-efficacy among nurses across diverse healthcare settings in Saudi Arabia: a mixed-methods cross-sectional study - Jassem Almualem; Doaa Alabdulbaqi; Fatimah Alzain; Manal Bazboz; Amal Zahran; Zainab Alsaffar; Jawad Almzain; Lamees Almansour; Amal Alzaher; Heba Altalaq; Amnah Bawady; Zaher Alhabib; et al. (BMC Nursing, 2026)