PDC is one of the most popular methods to calculate medication adherence and is endorsed and validated by the PQA as a high-quality measure of medication adherence.118,119 * Clinical Recommendations 2017 Hypertension Clinical Practice Guidelines4 In adults with hypertension, dosing of antihypertensive medication once daily rather than multiple times daily is beneficial to improve adherence.115,116,120 (Class 1, Level of Evidence: B-R) Adults initiating a new or adjusted drug regimen for hypertension should have a follow-up evaluation of adherence and response to treatment at monthly intervals until control is achieved.59,60,121 (Class 1, Level of Evidence: B-R) Use of BP-lowering medications is recommended for secondary prevention of recurrent CVD events in patients with clinical CVD and an average SBP of 130 mmHg or higher or an average DBP of 80 mmHg or higher, and for primary prevention in adults with an estimated 10-y atherosclerotic cardiovascular disease (ASCVD) risk of 10% or higher and an average SBP 130 mmHg or higher or an average DBP 80 mmHg or higher.29,37,42,43,46,122 125 (Class 1, Level of Evidence: SBP: A, DBP: C-EO) Use of BP-lowering medication is recommended for primary prevention of CVD in adults with no history of CVD and with an estimated 10-y ASCVD risk <10% and an SBP of 140 mmHg or higher or a DBP of 90 mmHg or higher.39,125 128 (Class 1, Level of Evidence: C-LD) Initiation of antihypertensive drug therapy with 2 first-line agents of different classes, either as separate agents or in a fixed-dose combination, is recommended in adults with stage 2 hypertension and an average BP more than 20/10 mmHg above their BP target. 