Adverse drug reactions - examples of detection of rare events using databases.

It is recognised that randomised controlled trials are not feasible for capturing rare adverse events. There is an increasing trend towards observational research methodologies using large population-based health databases. These databases offer more scope for adequate sample sizes, allowing for comprehensive patient characterisation and assessment of the associated factors. While direct causality cannot be established and confounders cannot be ignored, databases present an opportunity to explore and quantify rare events. The use of databases for the detection of rare adverse events in the following conditions, sudden death associated with attention deficit hyperactivity disorder (ADHD) treatment, retinal detachment associated with the use of fluoroquinolones and toxic epidermal necrolysis associated with drug exposure, are discussed as examples. In general, rare adverse events tend to have immediate and important clinical implications and may be life-threatening. An understanding of the causative factors is therefore important, in addition to the research methodologies and database platforms that enable the undertaking of the research.

Medication Adherence and Blood Pressure Control Among Hypertensive Patients With Coexisting Long-Term Conditions in Primary Care Settings: A Cross-Sectional Analysis.

Hypertension is a typical example of long-term disease posing formidable challenges to health care. One goal of antihypertensive therapy is to achieve optimal blood pressure (BP) control and reduce co-occurring chronic conditions (multimorbidity). This study aimed to assess the influence of multimorbidity on medication adherence, and to explore the association between poor BP control and multimorbidity, with implications for hypertension management.A cross-sectional design with multistage sampling was adopted to recruit Chinese hypertensive patients attending general out-patient clinics from 3 geographic regions in Hong Kong. A modified systemic sampling methodology with 1 patient as a sampling unit was used to recruit consecutive samples in each general out-patient clinic. Data were collected by face-to-face interviews using a standardized protocol. Poor BP control was defined as having systolic BP/diastolic BP ≥130/80 mm Hg for those with diabetes or chronic kidney disease; and ≥140/90 mm Hg for others. Medication adherence was assessed by a validated Chinese version of the Morisky Medication Adherence Scale. A simple unweighted enumeration was adopted to measure the combinations of coexisting long-term conditions. Binary logistic regression analysis was conducted with medication adherence and multimorbidity as outcome variables, respectively, after controlling for effects of patient-level covariates.The prevalence of multimorbidity was 47.4% (95% confidence interval [CI] 45.4%-49.4%) among a total of 2445 hypertensive patients. The proportion of subjects having 0, 1, and ≥2 additional long-term conditions was 52.6%, 29.1%, and 18.3%, respectively. The overall rate of poor adherence to medication was 46.6%, whereas the rate of suboptimal BP control was 48.7%. Albeit the influence of multimorbidity on medication adherence was not found to be statistically significant, patients with poorly controlled BP were more likely to have multimorbidity (adjusted odds ratio 2.07, 95% CI 1.70-2.53, P < 0.001). Diabetes was the most prevalent concomitant long-term condition among hypertensive patients with poor BP control (38.6%, 95% CI 35.8-41.4 vs 19.7%, 95% CI 17.5-21.9 for patients with good BP control, P < 0.001).Multimorbidity was common among hypertensive patients, and was associated with poor BP control. Subjects with coexisting diabetes, heart disease, or chronic kidney disorder should receive more clinical attention to achieve better clinical outcomes.

Determinants of medication adherence and blood pressure control among hypertensive patients in Hong Kong: a cross-sectional study.

INTRODUCTION: Despite effective treatments, suboptimal medication adherence substantially hinders blood pressure (BP) control among hypertensive patients. This study aimed to evaluate the determinants of medication adherence and BP control among hypertensive patients in Hong Kong. METHODS: A cross-sectional study was conducted. Adult patients aged>18years taking at least one type of antihypertensive drugs were recruited from four clinics in Hong Kong. Each patient completed a self-administered questionnaire, including socio-demographic variables and items related to knowledge, illness perception and medication adherence. Medication adherence was measured by the eight-item Morisky Medication Adherence Scale (MMAS-8), with a score>6 defined as "good adherence". BP was measured, and optimal control was defined as systolic BP<140mmHg and diastolic BP<90mmHg. RESULTS: Among 2445 patients, 55.1% and 52.5% had optimal medication adherence and BP control, respectively. Binary logistic regression analyses were conducted with optimal medication adherence and BP control, respectively, as the outcome variables. Advanced age (adjusted odds ratio [aOR] 1.012, 95% CI 1.002-1.022, p=0.014), unemployment (aOR for employed 0.782, 95% CI 0.628-0.975, p=0.029), and good self-perceived health status (aOR 2.155, 95% CI 1.711-2.714, p<0.001) were associated with good adherence; whereas being married (aOR 1.265, 95% CI 1.038-1.542, p=0.020) and having no co-morbidity (aOR for morbidity count 0.713, 95% CI 0.639-0.796, p<0.001) were associated with optimal BP control. CONCLUSION: Evidence-based, adherence-enhancing interventions should be targeted on younger subjects; employed patients; and those with poor self-perceived health status. Patients who are single and those with comorbidities should be closely monitored for their BP control.

Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review.

The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59-0.90% and 0.77-1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups.

Determinants of medication adherence to antihypertensive medications among a Chinese population using Morisky Medication Adherence Scale.

BACKGROUND AND OBJECTIVES: Poor adherence to medications is one of the major public health challenges. Only one-third of the population reported successful control of blood pressure, mostly caused by poor drug adherence. However, there are relatively few reports studying the adherence levels and their associated factors among Chinese patients. This study aimed to study the adherence profiles and the factors associated with antihypertensive drug adherence among Chinese patients. METHODS: A cross-sectional study was conducted in an outpatient clinic located in the New Territories Region of Hong Kong. Adult patients who were currently taking at least one antihypertensive drug were invited to complete a self-administered questionnaire, consisting of basic socio-demographic profile, self-perceived health status, and self-reported medication adherence. The outcome measure was the Morisky Medication Adherence Scale (MMAS-8). Good adherence was defined as MMAS scores greater than 6 points (out of a total score of 8 points). RESULTS: From 1114 patients, 725 (65.1%) had good adherence to antihypertensive agents. Binary logistic regression analysis was conducted. Younger age, shorter duration of antihypertensive agents used, job status being employed, and poor or very poor self-perceived health status were negatively associated with drug adherence. CONCLUSION: This study reported a high proportion of poor medication adherence among hypertensive subjects. Patients with factors associated with poor adherence should be more closely monitored to optimize their drug taking behavior.

Effectiveness of a pharmacist-led drug counseling on enhancing antihypertensive adherence and blood pressure control: a randomized controlled trial.

Adherence to antihypertensive medications represents a crucial success factor for optimal blood pressure (BP) control in clinical practice. This study evaluated whether an additional pharmacist-led medication counseling could achieve better optimal BP control and enhance compliance. In a designated family clinic in a region with similar resident characteristics to Hong Kong, patients taking ≥ one antihypertensive agent with suboptimal compliance were randomly allocated to a brief 3-minute drug advice (control; n = 161) or pharmacist counseling (intervention; n = 113). The two groups were compared by repeated measure ANOVA at 3-months and 6-months with BP control and medication compliance as outcome variables, respectively. The proportions of patients having optimal compliance increased from 0% to 41.1% at 3 months and 61.9% at 6 months (P < 0.001). The proportion of patients having optimal BP control improved from 64.1% at baseline to 74.0% at 3 months and 74.5% at 6 months (P = 0.023). There were no significant differences between the two groups in the changes of BP control and compliance levels. This study implied that even a brief 3-minute drug advice might lead to improved BP levels among patients on antihypertensive medications in general practice, but did not demonstrate additional effects by pharmacist counseling.