Lowered blood pressure targets identify new, uncontrolled hypertensive cases: patient characteristics and implications for services in Thailand

Global Burden, Regional Differences, Trends, and Health Consequences of Medication Nonadherence for Hypertension During 2010 to 2020: A Meta-Analysis Involving 27 Million Patients

Background

Nonadherence to antihypertensive medications is the leading cause of poor blood pressure control and thereby cardiovascular diseases and mortality worldwide.

Methods and Results

We investigated the global epidemiology, regional differences, and trend of antihypertensive medication nonadherence via a systematic review and meta‐analyses of data from 2010 to 2020. Multiple medical databases and clinicaltrials.gov were searched for articles. Observational studies reporting the proportion of patients with anti‐hypertensive medication nonadherence were included. The proportion of nonadherence, publication year, year of first recruitment, country, and health outcomes attributable to antihypertensive medication nonadherence were extracted. Two reviewers screened abstracts and full texts, classified countries according to levels of income and locations, and extracted data. The Joanna Briggs Institute prevalence critical appraisal tool was used to rate the included studies. Prevalence meta‐analyses were conducted using a fixed‐effects model, and trends in prevalence were analyzed using meta‐regression. The certainty of evidence concerning the effect of health consequences of nonadherence was rated according to Grading of Recommendations, Assessment, Development and Evaluations. A total of 161 studies were included. Subject to different detection methods, the global prevalence of anti‐hypertensive medication nonadherence was 27% to 40%. Nonadherence was more prevalent in low‐ to middle‐income countries than in high‐income countries, and in non‐Western countries than in Western countries. No significant trend in prevalence was detected between 2010 and 2020. Patients with antihypertensive medication nonadherence had suboptimal blood pressure control, complications from hypertension, all‐cause hospitalization, and all‐cause mortality.

Conclusions

While high prevalence of anti‐hypertensive medication nonadherence was detected worldwide, higher prevalence was detected in low‐ to middle‐income and non‐Western countries. Interventions are urgently required, especially in these regions. Current evidence is limited by high heterogeneity.

Registration

URL: www.crd.york.ac.uk/prospero/; Unique identifier: CRD42021259860.

Is the Association between Herbal Use and Blood-Pressure Control Mediated by Medication Adherence? A Cross-Sectional Study in Primary Care

Herbs have been used worldwide for many health conditions as an alternative treatment, including hypertension. Their use might affect the use of conventional medications, as well as blood-pressure control. This study aims to determine whether the potential associations between herb use and high blood pressure in hypertensive patients was mediated by medication adherence. A cross-sectional study was conducted using questionnaires and available medical databases at a primary care clinic of a tertiary hospital in Chiang Mai, Thailand. The data were collected from 450 patients with essential hypertension. Drug adherence was assessed by the Morisky Green Levine Medication Adherence Scale. The history of herbs used in the past three months was obtained. The goal of controlled blood pressure was defined in accordance with the Thai guidelines on the treatment of hypertension. Of the total 450 patients, 42% had high adherence. Nearly 18% reported herb use in the past three months. High medication adherence was strongly associated with blood-pressure control when adjusted for age, gender, education, the presence of comorbidities, and herb use (aOR 26.73; 95% CI 8.58–83.23; p < 0.001). The association between herb use and blood-pressure control did not achieve statistical significance (p = 0.143). However, the adjusted odds ratio of the association between herb use and blood-pressure control was diluted from 0.67 to 0.83 when adding the factor of medication adherence to the model. In conclusion, herb use was associated with poor medication adherence, which was in turn associated with poor blood-pressure control. Assessing this information contributes to appropriate exploration and counseling.

Clinical audit of adherence to hypertension treatment guideline and control rates in hospitals of different sizes in Thailand

A clinical audit of hospitals in Thailand was conducted to assess compliance with the national hypertension treatment guidelines and determine hypertension control rates across facilities of different sizes. Stratified random sampling was used to select sixteen hospitals of different sizes from four provinces. These included community (<90 beds), large (90–120 beds), and provincial (>120 beds) hospitals. Among new cases, the audit determined whether (i) the recommended baseline laboratory assessment was completed, (ii) the initial choice of medication was appropriate based on the patient's cardiovascular risk, and (iii) patients received medication adjustments when indicated. The hypertension control rates at six months and at the last visit were recorded. Among the 1406 patients, about 75% had their baseline glucose and kidney function assessed. Nearly 30% (n = 425/1406) of patients were indicated for dual therapy but only 43% of them (n = 182/425) received this. During treatment, 28% (198/1406) required adjustments in medication but this was not done. The control of hypertension at six months after treatment initiation was 53% varying between 51% in community and 56% in large hospitals (p < .01). The hypertension control rate at last visit was 64% but varied between 59% in community hospitals and 71% in large hospitals (p < .01). Failure to adjust medication when required was associated with 30% decrease in the odds of hypertension control (OR 0.69, 95% CI 0. 50 to 0.90). Failure to comply with the treatment guidelines regarding adjustment of medication and lost to follow‐up are possible target areas to improve hypertension control in Thailand.