The influence of personality on reported pain and self-efficacy for pain management in older cancer patients

Abstract

This study examines the relationship of personality traits and affect on cancer-related pain in 150 older adults receiving outpatient treatment at a comprehensive cancer center. Regression analyses revealed extraversion as a significant predictor of current pain, with openness to experience as a significant indicator of average pain. Similarly, positive affect and negative affect were significant predictors of self-efficacy for pain management. Moderation models showed that conscientiousness and extraversion were significant moderators in the relationship between self-efficacy for pain management and worst pain. These findings suggest that different personality types may influence perceptions of pain severity.

Keywords

affect cancer older person physical symptoms self-efficacy

Introduction

The risk of experiencing cancer-related pain is of growing concern particularly for cancer patients over 65 years of age (Caltagirone et al., 2010; Costantini et al., 2009), who are estimated to represent approximately 77 percent of all cancer diagnoses (American Cancer Society, 2012). Although pain is recognized as one of the most common symptoms reported by older cancer patients (McMillan et al., 2008; Stark et al., 2012; Stromgren et al., 2006), there remains a lack of research documenting the psychological and social impact of cancer-related pain among this adult population (Caltagirone et al., 2010).

The effect of personality on health is one of the most studied topics in personality psychology, health psychology, and behavioral medicine (Smith and Spiro, 2002; Turiano et al., 2012). The Five Factor Model (FFM) of personality, neuroticism, extraversion, openness to experience, conscientiousness, and agreeableness brings organization to the study of personality and health (Costa and McCrae, 1989; Smith and Williams, 1992). Inventories of the FFM can provide distinct predictions of health or allow for recognition of variables that can be considered risk factors for morbidity and mortality (Fry and Debats, 2009; Smith and Spiro, 2002). A variety of studies using the FFM of personality have continually shown significant effects of personality on the incidence and prevalence of illnesses, poor health behaviors, and adaptation to illness and stressors (Asghari and Nicholas, 2006; Boyce and Wood, 2011; Calabrese et al., 2006; Flett et al., 2011; Phillips and Gatchel, 2000). Studies have also identified second-order FFM traits such as perfectionism, mainly comprising conscientiousness and neuroticism, which act as protective or maladaptive factors for mortality and longevity (Fry and Debats, 2009).

Despite these data, an area of research that warrants further study is the relationship between the FFM of personality and cancer pain in general and among older adults in particular. The majority of research has primarily focused on optimism and neuroticism, in relation to multiple types and sources of pain (Dahl, 2010; Scheier and Carver, 1985). Yet, data examining cancer-related pain severity show that the experience and expression may be influenced by the patient’s personality type (Calabrese et al., 2006; Dahl, 2010; Ramirez-Maestre et al., 2004).

Similar to the literature documenting the relationship between personality and pain (beliefs and control) (Judge et al., 2002; Williams et al., 2004), there is evidence supporting the association between the FFM of personality and self-efficacy for managing pain (Porter et al., 2008). Asghari and Nicholas (2006), for example, found that those who scored higher on neuroticism were more likely to report higher rates of catastrophizing, anxiety, and passive coping regarding chronic pain. In addition, data show that patients with higher negative affect were associated with higher levels of chronic pain, lower self-efficacy for pain management (PSE), and higher distress (Kersh et al., 2001).

The objective of this study was to determine the influence of the FFM of personality and positive and negative affect on reported pain severity and PSE in older cancer patients. This research was guided by several hypotheses: (1) patients with low levels of neuroticism, high openness to experience, high conscientiousness, and positive affect will report less pain severity; and (2) personality (e.g. high neuroticism, high openness to experience) and affect (e.g. high positive, low negative) will moderate the relationship between PSE and reported pain severity.

Methods

Participants

A secondary analysis of self-reported data on psychosocial, behavioral, and cultural indicators was performed on patients receiving outpatient treatment services at a National Cancer Institute–Designated Comprehensive Cancer Center. Adult patients, who self-identified as Black or White, had a cancer diagnosis at any stage, ≥55 years of age, rated their cancer-related pain as ≥4, able to read and understand English, and provided consent were included for study participation. Data were collected through patient interviews. This investigation was approved by the cancer center Protocol Review Monitoring Committee and the university Institutional Review Board (IRB).

Recruitment and interview process

Recruitment efforts and interviews were from patients receiving treatment at the Psychosocial & Palliative Care, Clinical Research, or Infusion clinics. Patients were approached and recruited by the research assistant during the patient’s clinic visit to determine their interest and eligibility for study participation. Once it was determined that the patient was eligible for study participation, consent was obtained.

All interviews were conducted between January 2011 and December 2011. Each interview lasted approximately 45 minutes. Respondents were compensated for their participation in the study.

Measures

Unless otherwise stated, all measures had established reliability and validity.

Personality

Personality was evaluated using the Ten Item Personality Inventory (TIPI), which examines the 5 dimensions of the FFM of personality (neuroticism, extraversion, conscientiousness, openness to experience, agreeableness). Each factor includes pairs of personality trait descriptors rated on a 7-point Likert scale (1 = strongly agree to 7 = strongly disagree). Sample items include the following: “I see myself as anxious or easily upset” and “I see myself as dependable or self-disciplined.” Scores are averaged for each factor, with high scores endorsing a stronger affirmation of the personality dimension (Gosling et al., 2003).

Affect

Positive and negative affect were measured using the 20-item Positive and Negative Affect Scale (PANAS) (Watson et al., 1988). Each scale consists of 10 mood-related adjectives (e.g. attentive, upset, and determined), rated on a 5-point Likert scale (1 = very slightly or not at all to 5 = extremely), assessing frequency over a 4-week time period. Scores were summed for each subscale, with high scores indicating a higher affective type (positive or negative) (Watson et al., 1988).

Pain severity

The Brief Pain Inventory (BPI) is a 32-item quantitative measurement tool designed to assess clinical pain. For the purpose of this study, a mean (total) pain severity score (composite of 4 single pain items: current, average, worst, and least pain) and scores from each of 4 single items were included in subsequent analyses. Response choices were rated on an 11-point numeric summated rating scale (0–10, with high scores indicating more of the symptom) (Cleeland, 1989).

Pain interference

A subscale of the BPI was used to measure how much pain interferes with daily activities. The subscale includes 7 items (general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life) measured on an 11-point numeric summated rating scale (0–10, with high scores indicating more interference) (Cleeland, 1989).

Self-efficacy

The Chronic Pain Self-Efficacy Scale (CPSS), a 22-item instrument, was included to measure perceived self-efficacy to cope with chronic pain. The measure consists of 2 subscales: PSE and self-efficacy for coping with other symptoms (CSE). For the purpose of this investigation, only the PSE subscale was included in subsequent analyses. Response item scores were averaged on an 11-point numeric scale (10–100, increments of 10), with higher scores endorsing greater self-efficacy (Anderson et al., 1995).

Clinical variables

The Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12) was included to examine measures of physical and mental health. The scale consists of 12 questions on 8 dimensions of health: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health (Ware et al., 1996). Specific to this study, the Physical Component Summary (PCS; physical functioning, physical roles, bodily pain, and general health) and Mental Component Summary (MCS; vitality, social functioning, emotional roles, and mental health) subscales were used to examine physical and mental health, respectively. Summary scores were obtained for each subscale and analyzed in the analyses. A checklist of physical comorbidities and type of cancer was also assessed.

Demographic characteristics

Participant demographics of age, race, marital status, education, employment, occupation, and household income were measured.

Analyses

Descriptive analyses and Pearson correlations were calculated to provide a profile of the patients’ demographic, psychological, clinical, and pain-related characteristics. Power analyses were conducted to ensure adequate statistical power using the software package, GPower 3.1.3 (Faul et al., 2007). Hierarchical linear regressions were calculated to determine which FFM personality traits and affect were significant predictors of pain severity and pain interference, while controlling for demographic, psychological, and clinical variables.

The moderation of PSE and reported pain severity by high/low personality traits and affect was evaluated through moderated regression analyses as described by Aiken and West (1991). In this approach, the dependent variables (total, worst, least, average, and current pain severity) were regressed on the main effect predictor variable (PSE), main effect moderator variable (high/low personality and affect), and their interaction (PSE × high/low personality/affect). Once a significant moderator effect was determined, predicted values of the outcome variable for representative groups were computed. The PANAS and TIPI personality factors were dichotomized at the median score to facilitate interpretation of interactions in the regression and moderation models. All analyses were performed using IBM SPSS Statistics 20.0 (IBM Corp, Armonk, NY).

Results

Demographic and health characteristics

The sample consisted of older Black and White patients (N = 150), with a mean age of 65.38 years (standard deviation (SD) = 7.72 years). More than half of the sample was female and married. The majority (82%) of the participants were non-Hispanic White, and most (93%) had at least a 12th grade education. Breast, hematologic, and lung were the most common cancer diagnoses. Participants reported living with an average of 2.67 (SD = 2.21) comorbidities (in addition to cancer). On a 0–10 scale, participants reported that their average worse pain was 6.53 (SD = 2.57), least pain was 2.45 (SD = 2.15), average pain was 4.15 (SD = 2.01), and current pain was 2.89 (SD = 2.53). Participants reported that their pain interference on physical functioning was 4.80 (SD = 2.46).

Personality and affect

Openness to experience was the highest rated personality trait among the total sample (M = 4.57, SD = 1.18), with extraversion as the second highest (M = 4.55, SD = 1.24), followed by neuroticism (M = 4.38, SD = 1.00), agreeableness (M = 4.32, SD = 1.01), and conscientiousness (M = 4.26, SD = 0.88) on a 1–7 scale. The sample had a total positive affect score of 35.29 (SD = 7.91) and mean negative affect of 17.65 (SD = 6.67).

Hierarchical regression models

Significant predictors of pain severity (total, worst, least, average, and current) were calculated after controlling for important covariates (age, sex, race, education, marital status, number of chronic conditions, mental health, clinical variables, type of cancer, high/low FFM of personality, and high/low positive and negative affect). Due to multicollinearity among demographic variables, only education was included during the first step of model development. Total count of comorbidities was included in step 2. Personality variables and negative and positive affect were added in steps 3 and 4, respectively.

Total, worst, least, current, and average pain and pain interference

Although none of the FFM personality variables were significant predictors of total, worst, and least pain, education (β = −.19, 95% confidence interval (CI) = −.28 to −.01, p < .05) and comorbidities (β = .30, 95% CI = .11 to .40, p < .001) were significant indicators of total pain severity. When examining each of the 4 pain items, results showed education (β = −.18, 95% CI = −.39 to −.01, p < .05), comorbidities (β = .23, 95% CI = .05 to .46, p < .05), and negative affect (β = .19, 95% CI = .002 to .14, p < .05) as significant predictors of worst pain. Similarly, education (β = −.81, 95% CI = −.32 to −.01, p < .05) and comorbidities (β = .25, 95% CI = .06 to .40, p < .01) were significant indicators of least pain.

Analyses further showed that after controlling for demographic and clinical variables, education (β = −.20, 95% CI = −.32 to −.02, p < .05), comorbidities (β = .28, 95% CI = .09 to .41, p < .01), and openness to experience (β = .18, 95% CI = .11 to 1.38, p < .05) were significant predictors of average pain. Race (β = −.19, 95% CI = .04 to .67, p < .05), comorbidities (β = .25, 95% CI = .08 to .47, p < .01), and extraversion (β = −.24, 95% CI = −2.09 to −.37, p < .01) were significant indicators of current pain. Finally, regression analyses showed that negative affect (β = .28, 95% CI = .04 to .18, p < .01) was a significant indicator of pain interference on physical functioning.

PSE

Positive affect (β = .22, 95% CI = .09 to .93, p < .05) and negative affect (β = −.20, 95% CI = −1.07 to −.07, p < .05) were significant predictors of PSE. None of the remaining demographic, physical, or personality characteristics were statistically significant predictors.

Moderation analyses

Hierarchical regression models showed that worst pain × dichotomized extraversion (β = .05, p = .04) and worst pain × dichotomized conscientiousness (β = −.05, p = .04) were the only significant interactions of worst pain and personality. Results showed a positive association between PSE and worst pain, with those reporting high PSE and high extraversion also reporting greater worst pain (Figure 1). Additional analyses showed that the relationship between PSE and low extraversion was significantly different from the relationship between PSE and high extraversion (p < .05).

Figure 1.

Extraversion as a moderator of the PSE to worst pain severity relationship.

Significant differences were similarly found between high and low conscientiousness and their relationship with PSE (p < .01). Figure 2 presents the positive association between PSE and worst pain applies most strongly to patients with low conscientiousness, such that patients with low PSE and low extraversion tended to report the highest worst pain of all patients. Results from both figures imply that the highest reported worst pain severity was reported by patients who were characterized by high extraversion and low conscientiousness.

Figure 2.

Conscientiousness as a moderator of the PSE to worst pain severity relationship.

Discussion

This study explored the effect of the FFM of personality (neuroticism, extraversion, conscientiousness, agreeableness, and openness to experience) and positive and negative affect on reported pain severity, pain interference, and PSE in older cancer patients. Results showed that low extraversion and high openness to experience were significant predictors of current and average pain, respectively. Education and number of chronic conditions were significant predictors of total, worst, least, average, and current pain.

The finding that the number of chronic conditions was a predictor of cancer pain was not surprising. These results are congruent with earlier research in which morbidity count is associated with reported pain (Gartner et al., 2009; Portenoy and Lesage, 1999; Valeberg et al., 2008; Van Dijk et al., 2008; Wang et al., 2012). Of interest was the robust effect of education on cancer pain. Previously published studies have demonstrated that lower education levels are significant risk factors for chronic pain and lower pain treatment (Reyes-Gibby et al., 2007; Rustoen et al., 2003; Simone et al., 2012). Possible explanations are that patients with low educational levels may communicate their pain symptoms less effectively, experience financial barriers to accessing analgesics, or have greater concerns or misconceptions about analgesic use. Because patient educational level is shown to be an influential factor in achieving pain management, further research and clinical interventions addressing this disparity are needed.

Finding low extraversion as a significant predictor of greater current pain is supported by prior research suggesting that extraversion is negatively related to the perceived intensity of chronic pain (Phillips and Gatchel, 2000; Ramirez-Maestre et al., 2004). It is suggested that individuals with low extraversion may limit social involvement and internalize their thoughts, which may similarly be shown in behaviors when interacting with the patient’s primary care physician or in any medical environment. The tendency to be socially reserved may be a possible barrier to patient–physician communication particularly with regard to cancer treatment and pain management.

Conversely, results from the moderation analyses showed that reports of greater worst pain were observed in high extraverted patients. Although this contends with our findings, there is evidence suggesting that extraverts are likely to experience greater chronic pain and are more willing to ask for analgesics compared to introverts (Phillips and Gatchel, 2000; Wade et al., 1992). This trait may be advantageous such that patients are more forthcoming in reporting and having their symptoms appropriately treated and managed. Contrary to this notion, high extraversion may be related to over reporting of symptoms, with patients over exaggerating their symptoms.

Age or cohort effects may also be factors related to high extraversion and symptom reporting among this sample. For older generations, an expected patient role is to “be a good patient,” to not ask questions, rather adhere to the physician’s proposed treatment plan (Jacobsen et al., 2009). In addition, the patients may have difficulty discerning what a cancer-related symptom is and what is assumed as an age-related condition or change. These may result in burdensome symptoms such as pain, which may be unreported and/or undertreated.

Another possible age effect is the difficulty discerning what a cancer-related symptom is and what is assumed as an age-related condition or change. Older individuals, in particular those with low extraversion, may not report their pain because of the assumption that it is an expected part of aging, which may result in un-treated or undertreated pain. These findings suggest that clinicians and researchers need to be aware of age and cohort effects in relation to personality and pain management (Gatchel, 2000).

Our results further revealed that high openness to experience, which reflects high attentiveness in one’s personal experiences, was a predictor of average pain severity. Those with openness to experience tend to have great internal focus, intellectual curiosity, and desire engagement in new experiences and social activities. However, this may be a challenge for those living with cancer (and pain). Those with high openness to experience may be more sensitive to those limitations and experience frustration, anxiety, and depression due to their physical limitations. This may result in developing more maladaptive coping strategies (e.g. avoidance, disengagement), thereby exacerbating symptom awareness and reporting (Goubert et al., 2004; Hill and Gick, 2011).

High openness to experience as a predictor of average pain may also be related to the educational level of the sample. Since the majority of the sample was well educated, they may be more proactive in seeking information regarding their illness. While it is beneficial to be informed, the results suggest that individuals with high openness to experience may report higher pain because they may tend to be hypervigilant of their symptoms leading to anxiety and worry and increased reports of pain (Goubert et al., 2004; Hill and Gick, 2011).

Our results showed high positive affect and lower negative affect were significantly associated with self-efficacy and pain interference. These findings are congruent with previous studies that found positive affect was associated with higher pain self-efficacy, lower pain catastrophizing, and better health (Carver and Connor-Smith, 2010; Hu and Gruber, 2008; Pressman and Cohen, 2005). Since these individuals with positive affect are more likely to be confident in their own efforts in managing their pain, they may experience lower distress and higher quality of life.

Conscientiousness was found to be a significant moderator in the relationship between PSE and worst pain, with patients with low conscientiousness reporting higher worst pain than those with high conscientiousness. Conscientiousness, a trait defined by competence, personal reliability, and self-discipline, similar to those of perfectionism, has been associated with enabling various health behaviors including adherence to medical regimens, cancer screenings, and cancer treatment options (Block et al., 2007; Dahl, 2010; Hill and Gick, 2011). Patients demonstrating low conscientiousness may utilize maladapative behaviors such as avoidance with regard to their pain, suggesting that reported worse pain severity may be a consequence of decreased or diminished compliance to treatment. Consequently, these individuals may not have the ability or willingness to enact appropriate problem-solving skills, thus rendering them incapable in reducing their pain.

Results further showed that conscientiousness reduced the relationship between PSE and reported worst pain. One explanation for this moderated effect is the low stress exposure and high self-control behaviors associated with this personality trait. Conscientious individuals typically try to predict and manage potential stressors and regulate their behavior that can lead to health problems (i.e. pain). Thus, those demonstrating low conscientiousness may not have the confidence that pain can be managed (Hill and Gick, 2011; Jerram and Coleman, 1999). In future research, multidimensional models of the FFM of personality such as perfectionism, which has considerable overlap with conscientiousness, should be assessed as an independent predictor of cancer pain and PSE.

The limitations of the study should be identified. First, this was a cross-sectional study, therefore changes over time or established causal relationships in pain severity and personality could not be determined. Second, the personality data were self-reported, which may result in potential reporting bias such as social desirability. The majority of the sample was White and well educated, thus our ability to generalize these findings to other cancer populations is limited. Finally, the selection criteria for study participation included all types of cancers, and therefore, these results may not necessarily be generalized to studies focusing on a specific diagnosis(es). This limitation can, however, be viewed as positive in that the study explored pain severity, self-efficacy, and the personality of an outpatient population from a leading cancer center.

Conclusion

This research offers a new perspective on how different personality traits influence cancer pain management. In practice, addressing FFM personality traits may be an important consideration for cancer centers struggling to reduce pain among their patient population. These findings also show the importance of examining personality in epidemiological studies that may lead to findings of informed prevention strategies, intervention methods, and policy initiatives. Future studies exploring multidimensional models of personality characteristics (i.e. optimism, perfectionism) should be the next step to observe how the FFM of personality may influence the physical and mental health of cancer patients.

Footnotes

Acknowledgements

The authors are very grateful to all the participants who completed the survey in the parent study (1 K01 CA131722-01A1). We also thank the clinical staff who supported this research and assisted with participant recruitment.

Funding

The parent study (1 K01 CA131722-01A1) was funded by the National Institutes of Health.

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