Study Setting, Participants, and Recruitment
PRIMARY HYPERTENSION
Participants were recruited from April 2017 through January 2019 at the General Hospital of Ningxia Medical University, Yinchuan, China—a unique tertiary hospital in the province. Inclusion criteria were (1) being aged 18 to 80 years; (2) being diagnosed with primary hypertension, defined as a systolic BP (SBP) of ≥140 mm Hg or diastolic BP (DBP) of ≥90 mm Hg [