OBJECTIVES: While hypertension treatment guidelines emphasize the medical benefits of combined medication choice, consumption patterns of antihypertensive drugs raise worldwide several questions related to real-life therapeutic and cost-effectiveness. Hungary has a relatively poor track record: international comparative studies show Hungarian patients’ adherence to treatment to fall behind not only desirable targets but also international average values. In our analysis, we start from the hypothesis that medical benefits achievable through combined therapy are weakened through inadequate patient adherence, and we investigate into the health loss caused to Hungarian patients by insufficient persistence in combined hypertension therapy. Our goal is to determine how the real-life consumption patterns of combination hypertension therapy impact real-life therapeutic effectiveness and cost-effectiveness. METHODS: We use itemized prescription-level data from the Hungarian National Health Insurance Fund Administration’s (NHIFA) database. Our research covers patients whose therapy was initiated during 2008 or 2009 with high-value fix-dosage (one-pill) and non-fix-dosage (multiple-pill) angiotensin-converting enzyme inhibitor (ACEI) and calcium channel blocker (CCB) combinations, or angiotensin-receptor blocker (ARB) and CCB combinations. RESULTS: Adherence to treatment is measured as persistence on the initiating combination therapy. Firstly, ’hard’ persistence (which does not allow for add-on therapies) and ’add-on’ persistence (which allows for additional active substances being added to the therapy regime) are separately calculated, both for fix-dosage and non-fix-dosage combinations. Secondly, if the initiating therapy is a fix-dosage combination, parallel consumption of monocomponents is also analysed. Thirdly, we carry out a switch analysis to determine the active substances that patients had been taking before receiving a fix-dosage combination, or take after abandoning the fix dosage combined therapy. CONCLUSIONS: We hypothesize that substantial societal loss is caused by patient non-adherence in hypertension treatment and clinical advantages of combination therapies are significantly impaired. Our research will deliver exact calculations for the extent of the societal loss.