Introduction

Non-adherence with prescribed medication has been estimated at 60% in patients with chronic diseases1; the asymptomatic nature of hypertension appears to have a negative effect on adherence in this patient group2. The overall aim of the present study is to examine the influence of psychosocial variables on adherence to medication in hypertensive patients.

Methods

The study is ongoing and is being carried out in community pharmacies. The main variables being examined are depressive symptomatology, self-efficacy, social support, beliefs about medications and illness perceptions. Other variables, including patient demographics, complexity of prescribed regimen and concomitant illness are also being examined. Adherence is assessed by self-report and supported by patient medication records (PMRs) received from the patients' community pharmacies. Fifty nine community pharmacies in Northern Ireland are participating in data collection. All the collected data are being coded and entered into SPSS© for analysis. Pearson's correlation coefficients are being used to examine the strengths of the relationships with adherence and the other variables examined.

Results

101 patients have been recruited to date (40 males and 61 females). Over 80% of the sample is aged over 50. Almost 35% of the sample were found to be suffering from depressive symptoms (mean depression score =14.873). PMR data have not as yet been analysed, however, adherence to treatment measured by self-report was found to be high with only 12.9% of the sample classed as non-adherent. Depressive symptoms were found to be significantly negatively correlated with social support (r= -0.410, n= 90, p=0.000) and perceptions of personal control over the illness (r=-0.487, n=89, p=0.000) but not with adherence. Adherence was found to be significantly negatively correlated with specific control (r=-0.243, n=101, p=0.007) general harm (r=-0.257, n=101, p=0.005) and general overuse (r=-0.277, n=101, p=0.002) subscales of the Beliefs about Medications Questionnaire4.

Discussion

Discovering how psychosocial variables such as depression, social support and self-efficacy affect adherence may assist in the development of programmes to improve adherence to antihypertensive medication resulting in an improved health outcomes. Self-reported adherence was good in the current sample which has been a common finding in adherence research. No correlation between adherence and depression was found in the present sample although data collection is continuing and a larger sample size (target n=500) will help to clarify the stability of the presently reported correlations.

References

1. Dunbar-Jacob, J. & Mortimer-Stephens, M.K. (2001). Treatment adherence in chronic disease. Journal of Clinical Epidemiology, 54, S57-S60
2. Andrejak, M., Genes, N., Vaur, L., Poncelet, P., Clerson, P., & Carré, A. (2000). Electronic pill-boxes in the evaluation of antihypertensive treatment compliance: Comparison of once daily versus twice daily regimen. American Journal of Hypertension, 13, 184-190.
3. Radloff, L.S. (1977). The CES-D scale: A self-report depression scale for research in the general population. Applied Psychological Measurement 1:385-401.
4. Horne, R., Weinman, J. & Hankins, M. (1999). The Beliefs about Medicines Questionnaire: The development and evaluation of a new method for assessing the cognitive representation of medication. Psychology and Health 14: 1-24.