Development and psychometric testing of a breast cancer survivor self-efficacy scale.

Breast cancer survivors (BCSs) are the largest female cancer survivor group and include 2.6 million women in the United States (American Cancer Society, 2012). BCSs deal with problems related to the disease and treatment throughout their life. Compared to women without breast cancer, survivors experience more depression, anxiety, fatigue, and sexual dysfunction, as well as decreased marital satisfaction (Minton & Stone, 2008; Von Ah, Kang, & Carpenter, 2008). The construct of self-efficacy has demonstrated effectiveness for developing interventions that enable cancer survivors to manage symptoms, ultimately improving their overall quality of life (QOL) (Hoffman et al., 2009; Merluzzi, Philip, Vachon, & Heitzmann, 2011;Zachariae et al., 2003). The purpose of this article is to present the psychometric development of a breast cancer self-efficacy scale (BCSES) that can quantify self-efficacy for use in interventions that address long-term problems encountered by BCSs. Self-efficacy is a central construct in Bandura's (1977) social cognitive theory and is defined as an individual's perception of his or her ability to complete a given task. Self-efficacy predicts the effort expended for a given problem and the length of time an individual will maintain a behavior to gain an expected outcome toward a unifying theory (Bandura, 1977). Self-efficacy and future outcome expectations play central roles in behavior change. Self-efficacy includes (a) magnitude (level of task difficulty), (b) generality (whether one believes tasks can be accomplished across several situations or only under limited conditions), and (c) strength (the relative certainty an individual has relative to accomplishing a given task or behavior) (Bandura, 1977; Champion, Skinner, & Menon, 2005). Bandura (1997) postulated that self-efficacy mediates behavior through cognitive appraisal. Decreased self-efficacy has been associated with physical and psychological distress and lower QOL (Cunningham, Lockwood, & Cunningham, 1991; Han et al., 2005; Lev & Healey, 1999). For example, when a survivor does not believe that he or she can maintain a set schedule of exercise, inactivity can result, increasing fatigue and decreasing QOL. If survivors had increased self-efficacy in their ability to maintain an exercise schedule, routine exercise could be maintained, which is related to decreases in fatigue. A secondary data analysis of cancer survivors found that perceived self-efficacy for fatigue management served as a mediator between cancer-related fatigue and functional status. People with greater perceived self-efficacy for fatigue self-management had better scores on physical function status (Hoffman et al., 2009). Research also has identified a positive relationship between self-efficacy and better adjustment after diagnosis (Lev & Healey, 1999). Patients with greater self-efficacy for dealing with emotional issues experienced less difficulty in their interactions with healthcare providers (Han et al., 2005). Therefore, self-efficacy for a given task will predict effort expended, increasing the likelihood of a positive outcome, which increases overall QOL. Researchers have used the construct of self-efficacy to build interventions for BCSs that decrease symptom distress. These interventions have demonstrated that equipping women with self-management skills increases self-efficacy and decreases symptom distress encountered during survivorship (Cimprich et al., 2005). Although several cancer-specific measures for self-efficacy exist, they are not ideal for measuring self-efficacy specific to the needs of BCSs, nor do they exclusively focus on adjustment issues that occur a year or more after initial treatment. For example, the Cancer Behavior Inventory (CBI) contains 45 items and is generic to any type of cancer (Merluzzi & Martinez Sanchez, 1997). Moderate correlations were found among the six CBI factors and constructs such as the Sickness Impact Profile, the Coping Strategies Scale, and an adjustment-to-cancer scale. The time since diagnosis and information about current treatment were not described. The six subscales of the CBI measures a wide range of factors from dealing with treatment and diagnosis to coping with the disease. A second self-efficacy scale, the Stanford Inventory of Cancer Patient Adjustment (SICPA), was developed from the CBI and is used with patients newly diagnosed with breast cancer. A total of 38 items relate to a patient's ability to cope with challenging situations after diagnosis (Cunningham et al., 1991; Manne et al., 2006). Positive correlations were found between QOL and cancer-related self-efficacy, and negative correlations were found between self-efficacy and the Profile of Mood States. Responses were correlated with symptom outcomes at diagnosis and one year later (Manne et al., 2006). Only two domains of self-efficacy, personal management and affect management, were associated with better psychological outcomes (Manne et al., 2006). Although cancer-related self-efficacy scales have been developed and psychometrically tested, several concerns limit their usefulness. The current scales have targeted the immediate effects of surgery or chemotherapy, such as pain, nausea, and hair loss. However, problems experienced by survivors after treatment include fatigue, cognitive problems, depression and anxiety, fear of recurrence, marital and sexual difficulties, and concerns about overall QOL. In the first year after treatment, survivors transition from being recipients of care to reengaging as active participants in life. The scales that have been developed and psychometrically tested are lengthy, limiting their usefulness in a clinical setting. However, the lack of specificity of prior scales to the problems encountered by BCSs after initial treatment is most important. Although all cancer survivors may have some common concerns, many unique problems also arise that are specific to breast cancer, which further necessitates a BCSES that is psychometrically sound, relevant to long-term survivorship issues, and short enough to be clinically useful.