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# Education as a predictor of quality of life outcomes among disadvantaged men

## Abstract

Higher educational levels along with other factors such as literacy and communication with physicians have been associated with better outcomes for men with prostate cancer, but little research has focused on the relationship of educational attainment to self-efficacy for interacting with physicians been conducted on its effect on self-efficacy and health-related quality of life (HRQOL) among low-income, uninsured men. Data from 425 low-income, uninsured men with prostate cancer enrolled in UCLA's Men's Health Study were examined. We found that men with higher and lower education levels, including those who did not complete high school, had similar HRQOL and self-efficacy outcomes. Because of the close relationship between income and education, broader studies into the associations of these variables and prostate cancer outcomes are needed.

## Introduction

In the United States, 29 000 men are expected to die from prostate cancer in 2008. However, having at least a high school education is associated with a 54% reduction in mortality rates among African-American and a 33% reduction among non-Hispanic white men with prostate cancer.1 This may be related to findings that have found lower levels of education to be associated with later stage of cancer at diagnosis2, 3, 4 or with lower literacy levels.5 Also, a higher level of education has been associated with having an increased understanding of prostate health6 and reduced pelvic function distress.7 Education attainment is known to influence the ability to make informed decisions by men with prostate cancer regarding treatment and symptom management and is associated with higher levels of prostate cancer knowledge.4, 8 Many studies investigating self-efficacy in various clinical situations were conducted with Caucasian middle- and upper-income populations.9, 10, 11, 12, 13, 14, 15, 16, 17 None explored self-efficacy for interacting with physicians. The major study investigating perceived self-efficacy for interacting with physicians was conducted among older women with breast cancer.18 Our study of self-efficacy for interacting with physicians indicated that 23% of the low-income men in the study had low self-efficacy in this domain and associated with this was diminished satisfaction with care, worse symptom distress and lower confidence in the provider. Self-efficacy is particularly important for low-income men dealing with prostate cancer to have concerns heard and obtain information needed for symptom-management and informed decision-making.8 Level of education may affect a man's confidence in his ability to interact with a health professional such as his physician, which has potential impact on his health-related quality of life (HRQOL).

Whereas there is research available on literacy and health literacy, little research has focused on how educational attainment affects HRQOL and self-efficacy in low-income, uninsured men with prostate cancer. We sought to investigate the relationship between patient educational attainment, patient self-efficacy and general and disease-specific HRQOL outcomes in low-income men enrolled in a statewide public assistance program that provides prostate cancer care to low-income, uninsured men.

## Methods

### Subjects

Study participants were from IMPACT (Improving Access, Counseling and Treatment for Californians with Prostate Cancer), a state-funded program that provides free prostate cancer treatment to low-income men. Program eligibility requires having biopsy-proven prostate cancer, California residency, income of no more than 200% of the Federal Poverty Level and being uninsured. The Program has been described previously.19, 20

### Procedures

IMPACT enrollees are all invited to participate in the University of California, Los Angeles (UCLA) Men's Health Study, a longitudinal survey of clinical and patient-centered outcomes. Participation in the survey bears no influence on receipt of Program benefits, which (in addition to medical care) include a wide variety of psychosocial services provided by nurse case managers and clinical coordinators.

Data were collected through telephone interview, self-administered questionnaires and medical record abstraction. Telephone interviews were conducted by trained, language matched (Spanish or English) interviewers and included information on general HRQOL, spirituality, diet and medical decisional regret. Written questionnaires measured health behaviors, prostate cancer knowledge, disease-specific HRQOL, self-efficacy, satisfaction with health care, anxiety and distress. Participants were given a $10 incentive for each completed self-administered questionnaire and telephone interview. In May 2007, 629 participants had completed baseline surveys. Of those, 458 (73%) had also completed 6-month follow-up surveys. Of those, 425 (93%) provided education information, and this group constituted our study sample. Information on health-care facility, treatment and clinical stage were gathered from medical records. All procedures were approved by the University of California, Los Angeles Office for Protection of Research Subjects and were compliant with the Health Insurance Portability and Accountability Act. ### Instruments We measured HRQOL with the SF-12, version 2 (a 12-item version of the SF-36) that compiles HRQOL into eight domains and two summary scores (Physical and Mental component summary). The two SF-12 summaries correlate highly with the SF-36 (r2=0.938 and 0.905, respectively), have excellent empirical validity and high test–retest reliability (r2=0.89 and 0.76, respectively21). The SF-12 scores range from 0 to 100, where higher scores indicate better outcomes. We measured prostate-specific HRQOL with the University of California, Los Angeles Prostate Cancer Index short form (PCI-SF), a 15-item survey questionnaire that assesses urinary, bowel and sexual bother and function. The function scales measure incontinence, proctitis and erectile problems, and the bother scales assess how troubled a subject is with these symptoms. The PCI-SF scale score ranges from 0 to 100, where higher scores indicate better outcomes. The PCI-SF is a validated short version of the PCI, which is both valid and reliable in men with and without prostate cancer.22, 23, 24, 25 We measured self-efficacy using the Perceived Efficacy in Patient-Physician Interactions (PEPPI) short form. This self-administered, five-item survey assesses an individual's confidence in his/her ability to communicate with his/her physician. PEPPI has good convergent and discriminant validity and strong reliability (α=0.93).26 We measured comorbidity with the Charlson Comorbidity Index.27 ### Statistical analysis We stratified educational attainment into four levels: college graduate or more, some college completion, high school graduate and less than high school completion. We used χ2-analysis to explore associations between education level and clinical and demographic variables, including age, relationship status, ethnicity, primary language, household annual income, number of comorbidities, prostate-specific antigen (PSA) level, Gleason score, site of clinical care, cancer stage at enrollment and primary treatment choice. In our sample, we assumed that there were minimal and random changes in relationship status and education levels between baseline and the 6-month follow-up survey dates. Thus, for those individuals with missing relationship status or education level on the baseline survey, we imputed his/her data from the completed 6-month follow-up survey. We examined the association between education level and time in IMPACT using analysis of variance (ANOVA). To assess changes over time, we calculated a change score for each subject by subtracting his/her own baseline score from his/her own 6-month score for each outcome, such that a positive change score indicates an increase (or improvement) over time, and a negative change score indicates a decrease (or detriment) over time. We then conducted an ANOVA to compare the association between education level and the change scores from baseline to 6 months in general and disease-specific HRQOL. Finally, we performed multivariate linear regressions of the change scores separately for each quality of life outcome (with ‘less than high school’ as the referent group) while controlling for covariates that were bivariately associated with education level at the P0.2 level. Differences in outcomes domain scores were considered clinically meaningful if they were at least one-half standard deviation.28 All statistical analyses were performed with SAS 9.1 (Cary, NC, USA). ## Results Table 1 displays the patient characteristics. Nearly one-half of the men (47.4%) had not completed high school, and the vast majority (85%) reported yearly household incomes of less than$15 000. A little less than one-half of the men (47%) were between 60 and 65 years old at the time of the baseline survey, and another 38% of the sample population was less than 60 years old. Nearly three-fourths of the men (72%) were in a committed relationship, and 80% were of an ethnic minority group (56% Hispanic, 16% African American and 7% other). Almost one-half (43%) reported having one or more comorbidities. Slightly less than one-half (47%) had undergone radical prostatectomy as primary treatment. The remainder received radiation therapy (33%), hormonal therapy (16%) or were undecided or managed expectantly (3%) for their prostate cancer.

Men with less than a high school education were more likely to be Spanish-speaking, younger than age 65, received their care at a public facility and be involved in a committed relationship (Table 1). There were no statistically significant differences in other demographic and clinical characteristics by education level, but a near-significant trend (P=0.06) was seen in the incomes of the men stratified by education, where 54% of those who had not completed high school had an annual household income under \$15 000. Another trend was observed in the distribution of comorbidity, where 46% of men who did not complete a high school education reported having one or more comorbidities (P=0.12) (Table 1).

There were no statistically significant differences in change scores for the general or disease-specific HRQOL or self-efficacy measures (Table 2). Only bowel bother approached significance (P<0.10), with an association suggestive of a negative trend with increasing patient education level.

Multivariate linear regressions demonstrated that the rate of change in bowel bother of college graduates was 13 units greater than that of non-high-school graduates (P=0.04) (Table 3).

We also ran a sensitivity analysis to see if dividing the study sample into two groups of some college or more and high school graduate or less would produce the same results. The significance levels all remained the same across all the HQROL and self-efficacy outcomes (data not shown). Only bowel bother was significant (P=0.04); high school graduates had higher bowl bother scores (less bother) than those with at least some college.

## Discussion

Our study found that educational attainment had a measurable influence on social, emotional and physical functioning, as well as perceptions of symptoms related to prostate cancer and its treatment. Despite these differences, men with more or less education (all of whom received similar case management, counseling and medical care) had similar improvements in health outcomes during their first 6 months in the Program. Specifically, men who did and did not complete high school had no meaningful differences in their scores over this time period in the physical, emotional or social domains of general HRQOL, disease-specific function or bother or self-efficacy. This reflects the shared experience of changes in their physical health, ability to work and perform other daily activities, emotional well-being, mental health, bother due to bowel function and feelings of confidence in negotiating the health-care system.

The men in the UCLA Men's Health Study were all uninsured, impoverished and of low socioeconomic status. Previous studies of disparities in health-care outcomes for cancer patients have found a high incidence of disease comorbidity in populations of low socioeconomic status.29 Similar to other studies, we found a high incidence of comorbidity in men with less than a high school education in our men with low annual household incomes (both indicators of low socioeconomic status). Other studies have also observed an association between poor HRQOL outcomes and low socioeconomic status.30

Previous studies have also examined the influence of socioeconomic status on HRQOL in men with prostate cancer and found an inverse association between low socioeconomic status and comorbidity, sexual and urinary function and other HRQOL outcomes.31 Very few studies have examined the relationship between education level and HRQOL in men with prostate cancer. Penson et al.18 found that education is associated with general and disease-specific HRQOL on baseline surveys with college graduates reporting better social functioning scores than non-college graduates. There is, however, a paucity of information concerning the influence of education on temporal changes in HRQOL in men with prostate cancer. Knight et al.2 observed that education level influenced general and disease-specific domains of HRQOL (physical function, role physical, role emotional, vitality, mental health, social function, general health, urinary function, urinary bother and sexual function) in men receiving treatment for prostate cancer.

Our study found that the only disease-specific HRQOL domain significantly associated with education level was bowel bother. The change in mean bowel bother scores for college graduates was 13 units greater than among non-high-school graduates, with an increasing trend with greater education completed. That our results differ from Knight's may be attributed to differences in the demographic compositions of our samples (including ethnicity, education, household income and age) or to the case management intervention in the IMPACT Program. Our findings are consistent with those of Penson et al.,18 who found that education level did not predict HRQOL over time.

Our study is strengthened by the use of well-validated psychometric measures of HRQOL and confidence in interacting with physicians. However, it is important to note that our study was conducted with low-income men, the majority of whom were African Americans or non-English-speaking Hispanics. Hence, our findings may not be generalizable to all prostate cancer patients. In addition, we performed a sensitivity analysis to investigate the possible influence of including men who were enrolled in the IMPACT Program for a longer period of time at the time of baseline interview and survey administration. Examining only the subset that were enrolled for under 1 month at the time of their baseline survey, the difference in the bowel bother changes over time between college graduates and non-high-school graduates lost its statistical significance whereas nearly maintaining its magnitude. Taking this additional finding into consideration, it is evident that additional research is needed to understand the association between patient education and HRQOL.

## Conclusion

In conclusion, we found that men with higher and lower education levels, including those who did not complete high school, had similar HRQOL outcomes when participating in a public-assistance program that included a case management intervention. Our study found that men of all education levels experienced similar changes in their day-to-day functioning related to prostate cancer and its treatment. Because of the very close relationship between patient ethnicity, income and education, broader studies into the associations of these components of identity with prostate cancer outcomes are needed.

## Disclosure

All analyses, interpretations, and conclusions herein are those of the authors and not the State of California.

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## Author information

Authors

### Corresponding author

Correspondence to M S Litwin.

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Augustus, J., Kwan, L., Fink, A. et al. Education as a predictor of quality of life outcomes among disadvantaged men. Prostate Cancer Prostatic Dis 12, 253–258 (2009). https://doi.org/10.1038/pcan.2008.58

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### Keywords

• education
• quality of life
• self-efficacy
• low-income men

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