Medication Adherence in Patients With Uncontrolled Hypertension & Hypertensive Crisis Presenting to a Hospital Setting in Karachi, Pakistan

Abstract

BACKGROUND Hypertension is an established risk factor for cardiovascular disease. Non-adherence to antihypertensive medications contributes to poorly controlled hypertension while also increasing the risk of hypertensive crisis. The aim of our study was thus to estimate the frequency of adherence to antihypertensive medications in our population and also see if an association exists between adherence and the development of a hypertensive crisis. METHODS This cross-sectional study was undertaken on patients admitted to Aga Khan University Hospital, Karachi, Pakistan, between July 2020 and March 2022. All patients with uncontrolled hypertension with systolic blood pressure >140 and diastolic blood pressure >90 who were admitted through the emergency department were included. A systolic blood pressure over 180mmHg or diastolic blood pressure over 120mmHg, with or without end-organ damage was used to define a hypertensive crisis. Adherence to medications was assessed using the 4-item Morisky Green Levine (MGL) scale. Each item was scored as 1 and then added together to get a final score out of 4 with a score of ≥3 signifying adherence while a cumulative score of 0, 1, or 2 was classified as non-adherence. RESULTS We found that 64% of the cohort were adherent to their medications while 93 (36%) were non-adherent. The most common comorbid condition was found to be diabetes mellitus (54.8%). Around 146 (64.6%) patients were on a single anti-hypertensive agent. Depression as calculated according to the hospital anxiety and depression scale (HADS) was seen in 133 (51.2%) of our cohort while 147 (56.5%) had anxiety. Similar rates of adherence were seen amongst males (49.1%) and females (50.9%). The highest level of adherence was seen in the 61 to 75 years age group (34.9%) and in those with university-level education (30.6%). We also found a statistically significant association between adherence to antihypertensive medications with anxiety (p-value=0.048). Moreover, in the hypertensive crisis group, 40.7% of the patients were adherent to their antihypertensive medications while 54.8% were found to be non-adherent, with the p-value reaching statistical significance (p-value=0.028). CONCLUSION We found a higher rate of adherence (64%) in this inpatient hypertensive population as compared to previous studies in our population. We also found that non-adherence is a risk factor for the development of a hypertensive crisis. Therefore, at clinic visits, physicians should assess their patient's adherence to antihypertensive medications to prevent the development of a hypertensive crisis.