8 For adult outpatients with HTN, what is the effectiveness and comparative effectiveness and harms of initiating a combination of two or more drug classes versus initiating one drug and adding a second drug later on in selected patients? No evidence 9 For adult patients with resistant or difficult to control HTN, what is the effectiveness and comparative effectiveness and harms of adding any antihypertensive drug to an existing drug regimen of three or more drugs? 10 What are the effectiveness, comparative effectiveness, and harms of telehealth, mobile applications, or other new technologies to improve blood pressure control in adults with HTN? 1 cluster RCT 11 What are the effectiveness, comparative effectiveness, and harms of less conventional forms of HTN care delivery, such as clinical pharmacists-run clinic, nurses-run clinic, using established protocols? 5 cluster RCTs 12 For adult outpatients with HTN and prehypertension, should screening for asymptomatic HTN-mediated end-organ damage by performed? 2 prospective cohort studies Total Evidence Base 97 studies Abbreviations: HTN: hypertension; RCT: randomized controlled trial; SR: systematic review a. General Criteria for Inclusion in Systematic Review SRs or clinical studies published on or after December 15, 2013 to March 25, 2019. If multiple SRs addressed a KQ, we selected the most recent and/or comprehensive review. SRs were supplemented with clinical studies published subsequent to the SR. Studies must have been published in English. Publication must have been a full SR or clinical study; abstracts alone were not included. Similarly, letters, editorials, and other publications that were not full-length clinical studies were not accepted as evidence. SRs must have searched MEDLINE or EMBASE for eligible publications, performed a risk of bias assessment of included studies, and assessed the quality of evidence using a recognizable rating system, such as GRADE or something compatible (e.g.