Abstract

INTRODUCTION

A large portion of cardiovascular risk can be attributed to lifestyle factors, such as unhealthy diet, low physical activity, and smoking (Yusuf et al., 2004). Although the reduction of these unhealthy habits has resulted in a significant decline in mortality rate comparable to that shown by cardio-preventive pharmacotherapy, few patients successfully improve their negative health-behaviors and even fewer maintain acquired changes in the long-term (Dorneleas, 2008). Moreover, high non-adherence rates to cardio-protective medications and subsequent adverse outcomes have been well documented (Ho et al., 2008). Current research has demonstrated that difficulties with behavior change may be related to a lack of psychological flexibility, a concept targeted in acceptance and commitment therapy (ACT; Hayes et al., 1999).

Psychological flexibility is defined as the ability to be fully present in each moment which includes accepting one’s own internal experiences even when unpleasant and distressful, and willingly engaging in behaviors that are consistent with one’s life values (Hayes et al., 2006).

Two major concepts are involved in the definition of psychological flexibility: the present moment contact with one’s thoughts, emotions, and bodily sensations (experiential acceptance), and the importance of maintaining values-driven behaviors. In contrast, psychological inflexibility is the attempt to decrease cognitive and physical distress even when doing so may sacrifice long-term behavioral goals (Luoma et al., 2011).

Since adopting and maintaining a healthy lifestyle often entails distressing internal experiences, individuals with a low ability to tolerate internal distress might be less likely to adopt and maintain behavioral changes. Previous research evaluating adherence to health-behaviors note the importance of distress tolerance; for example, changes in diet often require compromises in portion-size and taste (Forman et al., 2007), exercise is associated with physical discomfort and exercise-anxiety (Butryn et al., 2011), and abstaining from nicotine is associated with cravings (Gifford et al., 2004; Brown et al., 2005). The relevant role of psychological inflexibility in preventing behavior change is confirmed by recent studies, showing the promise of acceptance-based interventions at increasing physical activity (Butryn et al., 2011), the ability of managing food cravings (Forman et al., 2007), and weight loss maintenance (Forman et al., 2009).

Moreover, variables found to be impacted by psychological inflexibility, such as depression, anxiety and stress have been shown to negatively impact cardiovascular risk and prognosis (Januzzi et al., 2000; Rozanski et al., 2005; Dimsdale, 2008; Rothenbacher et al., 2014) through the mediation of biological mechanisms such as hypertension and blood pressure reactivity to stress, (Strike and Steptoe, 2004) and behavioral pathways such as lower medication adherence and lesser likelihood to adopt healthy behaviors (Rothenbacher et al., 2014).

Psychological inflexibility is also inversely associated with quality of life, perceived health, and positive emotional experiences (Bond et al., 2011; Gaudiano, 2011). Thus, it is important to investigate the relationship between psychological inflexibility, mental health, quality of life, and the development and progression of coronary heart disease. Understanding such associations will be especially useful in the context of secondary prevention efforts, such as cardiac rehabilitation.

While general measures of psychological inflexibility do exist, to date no instrument has been validated for reliably measuring cardiovascular disease-specific psychological inflexibility. The most established measure of general psychological flexibility is the Acceptance and Action Questionnaire (AAQ; Hayes et al., 2004), which cuts across diagnostic categories and psychological problems. Research on psychological inflexibility in many different samples has shown that the AAQ scores predict 16–25% of the variance in outcomes across a broad range of psychological health conditions (Hayes et al., 2006). However, versions with a specific focus may offer greater precision in the measurement of psychological flexibility within particular contexts or populations. For example, acceptance of pain as measured by the Chronic Pain Acceptance Questionnaire (CPAQ) appears to partially mediate the relationship between pain severity, and the degree of pain interference and emotional distress (Fish et al., 2010). Similarly, body image flexibility improved prediction of disordered eating, above and beyond overall psychological flexibility even after controlling for body image dissatisfaction and BMI (Sandoz et al., 2013). Comparable results have been shown for other specific variants of the AAQ and related measures of psychological flexibility in such areas as obesity (Lillis et al., 2009), diabetes (Gregg et al., 2007), epilepsy (Lundgren et al., 2008), tinnitus (Westin et al., 2008), substance abuse (Luoma et al., 2011) and smoking (Gifford et al., 2004).

These results provide support for the usefulness of developing measures of psychological flexibility that are domain specific.

Cardiovascular disease is a disease that requires adjustment to both change in lifestyle and change in self-conception (i.e., identification as a cardiovascular patient). This change in self-conception can be difficult and potentially harmful if the person with heart disease becomes distressed as a result of this new self-conception and begins to avoid disease-specific thoughts, feelings, and behaviors. Behavior-specific measures related to the adoption of healthy lifestyles, such as the Food AAQ (Juarascio et al., 2011) or the Physical Activity AAQ (Butryn et al., 2014) could be usefully adopted with cardiac patients. However, their use will provide information about those behaviors independent of heart disease, which is less helpful when attempting to alter behavior in the context of cardiovascular disease and a changing self-conception. Lastly, a single disease-specific measure will require less time from patients and participants than multiple behavior-specific measures, thus reducing overall patient burden.

Therefore the CardioVascular Disease AAQ (CVD-AAQ) was created to assess patient tendency to avoid difficult disease-related thoughts and feelings and the consequent lack of willingness to engage in recommended life-style changes.

The aim of the present study is threefold:

• (1)

  to evaluate the psychometric properties of CVD-AAQ;

• (2)

  to explore the association between patient demographics and CVD-AAQ scores;

• (3)

  to evaluate the association between CVD-AAQ scores, rates of medication adherence and BMI in a sample of cardiac patients.

MATERIALS AND METHODS

RESULTS

DISCUSSION

Although psychological inflexibility has been reported to play an important role in health-behavior change, there is currently no measure of this construct in the context of heart disease. Therefore, the CVD-AAQ was developed to fill the existing gap in the literature. The current study sought to investigate the psychometric characteristics of the CVD-AAQ in terms of factorial structure, reliability and validity.

The initial item pool was generated by applying the psychological inflexibility construct to the context of cardiovascular disease in order to measure the extent to which an individual makes cognitive and behavioral choices that are consistent with his/her values of health even when doing so lead to experiencing distressing thoughts or feelings. An EFA on this 10-item scale suggested a two-factor solution. However, reliability analyses showed that items loadings on the second factor did not significantly correlate with the overall scale and their deletion significantly increased Cronbach’s alpha. After the items’ removal, the resulting seven-item scale showed a 1-factor structure, a solution consistent with the AAQ-II. In conclusion, CVD-AAQ appears to measure the construct of psychological inflexibility with satisfactory internal consistency and test–retest reliability.

In addition to its sound factor structure and good reliability, our findings indicate that the CVD-AAQ is associated with variables to which it is theoretically tied. Specifically, the greatest association was observed with the AAQ-II, a general measure of the same construct, supporting the convergent validity of the instrument. On the other side, the absence of a significant correlation with all the coping strategies measured by the BRIEF-COPE, except for denial and acceptance, supported the divergent validity of the instrument.

Moreover, higher levels of cardiac-specific psychological inflexibility were concurrently associated with greater depressive symptoms, anxiety, and psychological stress and lower levels of psychological well-being. These results are highly consistent with previous research on general psychological inflexibility, which appeared to be a key process in the etiology and maintenance of psychopathology and psychological suffering (Hayes et al., 2006; Gaudiano, 2011).

Consistent with the existing literature (Bond et al., 2011), psychological inflexibility was not associated with demographic variables. Cardiac-specific psychological inflexibility was greater in patients with low rates of adherence to medical treatment—findings that mirror previous research on disease-specific psychological inflexibility (Weijman et al., 2005). This finding suggests that psychological flexibility may be associated with the adoption and maintenance of health behaviors, such as medication adherence, among patients with heart disease.

Cardiovascular Disease Acceptance and Action Questionnaire yields substantially different scores among cardiac patients with a BMI >25 compared with those with a BMI below 25. This finding indicates that the overweight patients are more psychologically inflexible and suggests that difficulty in weight management may be associated with the individual’s tendency to sacrifice long-term behavioral goals (e.g., healthy food choices and exercise) in the service of decreasing unpleasant and distressful internal experiences (e.g., food cravings and fatigue).

Moreover, this result is of great importance because BMI and adherence to medication are two relevant risk factors for cardiovascular disease. Notably, no between-group differences were detected using the AAQ-II, relative to both BMI and adherence. This result speaks to the incremental validity of CVD-AAQ and supports the usefulness of disease- and behavior-specific instruments for assessing psychological inflexibility.

Previous research suggests that psychological inflexibility plays an important role in the adoption and maintenance of health behaviors. Moreover, a preliminary investigation by Goodwin et al. (2012) found that a program to enhance psychological flexibility in a sample of cardiac patients effectively improved adherence to heart-healthy behaviors.

The current study is the first to evaluate the usefulness of a measure of psychological inflexibility specific to cardiovascular disease. The use of the CVD-AAQ may help identify patients who are more likely to be non-adherent. With further evaluation of the CVD-AAQ, it is possible that use of the instrument could help identify patients who are at risk for relapse or re-events. In an effort to begin such an evaluation, the CVD-AAQ will be employed to evaluate the mediational role of psychological flexibility in the context of a RCT comparing a brief ACT-based intervention to usual secondary prevention care of coronary heart disease (Spatola et al., 2014).

However, there are several limitations to the current study and further investigation is needed before this measure can be confidently used to assess the constructs of psychological inflexibility. Firstly, further tests of reliability and validity in other countries would ensure that the psychometric properties of this measure are well established and replicable. We considered running a confirmatory factor analysis in order to examine method variance, but since the initial one-factor solution which led to the development of the instrument was based on the same sample, we were concerned that any findings might be due to capitalization on chance, rather than true variance. Thus, we decided to not run this analysis until another sample could be obtained. Our recommendation is that future studies of the CVD-AAQ with other samples include a confirmatory factor analysis that allows for examination of whether the single factor solution found in our EFA is a better fit for the data than a two-factor solution. Secondly, the inclusion of a broader range of measures would be of particular utility for a deeper understanding of CVD-AAQ validity, with particular attention to be paid to other psychological inflexibility measures such as the Cognitive Fusion Questionnaire (Gillanders et al., 2014). Finally, longitudinal studies are needed in order to clarify the association between the CVD-specific psychological inflexibility and patient ability to adopt or maintain a heart-healthy lifestyle.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

REFERENCES