Quality of life of coronary artery disease patients after the implementation of planning strategies for medication adherence 1

OBJECTIVE: to compare the general and specific health-related quality of life (HRQoL) between the Intervention (IG) and Control (CG) groups of coronary artery disease patients after the implementation of Action Planning and Coping Planning strategies for medication adherence and to verify the relationship between adherence and HRQoL. METHOD: this was a controlled and randomized study. RESULTS: the sample (n=115) was randomized into two groups, IG (n=59) and CG (n=56). Measures of medication adherence and general and specific HRQoL were obtained in the baseline and after two months of monitoring. CONCLUSION: the findings showed that the combination of intervention strategies - Action Planning and Coping Planning for medication adherence did not affect the HRQoL of coronary artery disease patients in outpatient monitoring.


Introduction
Patient adherence to medication therapy is essential for the control of coronary artery disease (CAD) and prevention of its complications (1) , constituting one of the biggest challenges for the nursing care to coronary disease patients, given the high percentage of nonadherence to the therapeutic medication regimen (2) . This construct refers to the extent to which patients follow the instructions of their physician or other healthcare professionals (3) . It is a complex phenomenon influenced by a range of factors, including, individual beliefs, skills, financial resources and/or barriers, and social influences (3) . Among the causes of non-adherence, the need for continued treatment can be highlighted, as well as the perceived lack of immediate benefits, the potential for adverse effects, and the costs associated with the treatment (3) .

Medication adherence can have significant
impact on the health-related quality of life (HRQoL) in patients with chronic clinical conditions (4)(5) , including CAD (6) . Although they are different constructs, adherence and HRQoL are related to patients and should be considered when evaluating the impact of interventions that affect their health (7) . Furthermore, these constructs are considered distinct outcomes in the care process -while adherence constitutes an intermediate result, HRQoL can be understood as a final outcome of the treatment (7) . Thus, it is possible to assume that interventions outlined for optimizing adherence influence medication adherence a priori and subsequently the HRQoL.
Although targeted at different health conditions, some studies have investigated the relationship between HRQoL and adherence. Among these, cross-sectional studies with geriatric hypertensive patients (5) , the use of medication for treatment of acquired immunodeficiency syndrome (8) and treatment with lipid-lowering drugs (9) can be highlighted. A recent literature review showed that few longitudinal studies have evaluated the impact of a theory-based intervention for the promotion or optimization of medication adherence on the general and specific HRQoL of patients with chronic (10)

Subjects and Procedures
Data from this study are derived from a broader experimental study (11)

Data Collection
Data were gathered from June 2010 to May 2011, using structured interviews and consultation of the hospital medical records at two different times: Lourenço LBA, Rodrigues RCM, São-João TM, Gallani MC, Cornélio ME.
-T 0 (baseline): interview and consent of the patient to participate in the study obtained by signing the term. Data related to sociodemographic and clinical characterization, medication adherence (12) , factors related to non-adherence (13) and general and specific (15) HRQoL (14) were obtained; -T 2 (two months after T 0 ): adherence and HRQoL measures were again obtained.

Intervention
The intervention was applied at T 0 with only those patients in the IG and consisted of the formulation and implementation of plans, according to the theoretical assumptions of Implementation Intention (16)(17) , based on a previous Brazilian study (18) . Patients were asked to design, in conjunction with the researcher, action and coping plans related to medication adherence. At T 1 (one month after T 0 ) presential reinforcement of the planning strategies was performed, by reading together the plans prepared at T 0. The details of the intervention can be found in a previous study (11) .

Control
The patients allocated to the CG received the routine care of the unit, which consisted of the usual clinical monitoring performed at the outpatient clinic.
They were instructed to maintain their routine activities as well as their clinical follow-up appointments with the physician.

Instruments
-The Morisky Self-Reported Measure of Medication Adherence Scale (13) : composed of four questions relating to non-adherence to pharmacological treatment, structured in Likert-type scales with four or five answer choices, the sum of which generates a score ranging from 4 up to 18; the lower the score the higher the favorability to adherence.
Those who obtained a percentage of consumption of prescribed medications, equal to or greater than 80% (20) were considered "Adherent". For those who used more than one medication, the proportion of adherence was calculated through the mean of the percentages of adherence to each medication (12) . The patients classified in group I were considered "Adherent", and those classified in groups II, III, and IV "Non-adherent" (12) . score is calculated through the arithmetic mean of all the items answered, unless one of the domains is completely missing (22) . The Brazilian version of MacNew (15) is considered reliable, valid and simple to apply (15,23) . In the present study the reliability with respect to the internal consistency, assessed through Cronbach's alpha coefficient, ranged between 0.80 and 0.90 throughout the monitoring.
-The 36-item Short Form Health Survey -SF-36: is a generic evaluation instrument of the perceived health status (24) , which is easy to administer and comprehend. It consists of eight domains: Functional Capacity (ten items), Physical Aspects (four items), Pain (two items), General Health Status (five items), Vitality (four items), Social Aspects (two items), Emotional Aspects (three items), Mental Health (five items), and one question comparing the current health conditions with those of one year previous.
The final score ranges from zero (worst health status) up to 100 (best health status) (24) . The Brazilian version of the SF-36 (14) was used and, in the present study, the internal consistency, assessed through Cronbach's alpha coefficient, ranged between 0.80 and 0.90 throughout the monitoring.

Data Analysis
Descriptive analyzes were performed to characterize the sample according to sociodemographic, clinical, medication adherence, and HRQoL variables. Student's t-test was used to check for differences between sociodemographic and clinical variables and the general and specific HRQoL between the IG and CG groups at HRQoL. Correlation coefficients < 0.30 were considered of weak magnitude, between 0.30 and 0.50 as moderate and > 0.50 of strong magnitude (25) . The significance level adopted for the statistical tests was p ≤ 0.05.

Ethical Aspects
The study was approved by the Research Ethics   that were adherent, when using the overall evaluation of adherence measure (p=0.023) ( Table 1).

Analysis of Health Related Quality of Life (HRQoL) measures
Regarding the specific HRQoL (MacNew), significantly higher mean scores (p<0.05) for all domains of the MacNew were observed in the IG at T 2 , when compared to the baseline (T 0 ). However, a significant increase in the scores of the majority of the MacNew domains was also observed in the CG, except in the emotional functioning domain, however, these differences were not statistically significant (  Aspects (p<0.05) domains, when compared to the scores obtained at T 0 . In the CG no significant differences were observed between the scores obtained at T 2 and T 0 .
While the intervention explained 5% of the variability of the proportion of adherence measure (11) , the linear regression analysis showed that the Intervention was not able to explain the variability of the general and specific HRQoL measures. In the IG at T 0, no correlations were found between the proportion of adherence and the specific HRQoL.

Quality of Life
At T 2 , significant weak to moderate correlations were

Discussion
This study aimed to compare the general and specific HRQoL of coronary artery disease patients allocated in IG and CG after implementing an intervention based on Action Planning and Coping Planning strategies for medication adherence, as well as to verify the existence of a relationship between adherence and HRQoL over two months of monitoring.
The findings indicate that at T 2 , the IG patients The exact mechanism by which medication adherence is associated with HRQoL is still unknown, with suggestions that HRQoL is part of a complex network of psychosocial characteristics that influence the patient's ability to cope with the chronicity of the disease (5) .
Previous findings (4) involving type 2 diabetic patients showed that medication adherence was not associated with the HRQoL domains. However, an association was observed with the combination of knowledge about the medical prescription and the attitude toward medication adherence, indicating the need for research into the determinant psychosocial variables for adherence behavior.
The absence or weak relationship between adherence and HRQoL were observed in other studies using self-reported measures (6) as well as those using electronic records of prescriptions (4,8) . Thus, our results

Conclusion
The findings indicate that the intervention based