Communication Message Strategies for Increasing Knowledge About Prostate Cancer Screening

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1 Journal of Cancer Education, 24: , 2009 Copyright AACE and EACE ISSN: print / online DOI: / HJCE Communication Message Strategies for Increasing Knowledge About Prostate Cancer Screening Prostate Cancer Knowledge LAUREN A. MCCORMACK, PHD, MSPH, CARLA M. BANN, PHD, PAMELA WILLIAMS-PIEHOTA, PHD, DAVID DRISCOLL, PHD, CINDY SOLOE, MPH, JON POEHLMAN, PHD, TZY-MEY KUO, PHD, KATHLEEN N. LOHR, PHD, STACEY L. SHERIDAN, MD, CAROL E. GOLIN, MD, RUSSELL HARRIS, MD, SAMUEL CYKERT, MD Abstract Background. This community-based intervention study examined the effects of 2 different message strategies for presenting information about the prostate specific antigen (PSA) test. Methods. A quasi-experimental longitudinal design with 2 intervention and 1 control group. Results. Knowledge increased significantly among participants who received either version of the intervention message and remained elevated at 12 months. Presenting information in the context of other men s health issues was associated with greater increases in knowledge relative to PSA only. Conclusions. Community-based interventions can increase knowledge about prostate cancer screening. Clinicians need to take careful account of what their patients understand and correct misperceptions. The decision to be screened for prostate cancer can be controversial because there is uncertainty about whether testing reduces morbidity and mortality. The US Preventive Services Task Force (USPSTF) 1,2 concluded that it could not recommend either for or against routinely screening men for prostate cancer because the evidence was insufficient to determine if the benefits outweighed the harms. Given the uncertainty, most major medical organizations (eg, the American Medical Association, the American Cancer Society) recommend using Received from RTI International, *Research Triangle Park, NC (LAM, CMB, PW-P, DD, CS, JP, T-MK, KNL); Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, Chapel Hill, NC (SLS, CEG, RH); and Internal Medicine Program, Moses Cone Hospital, Greensboro, NC (SC). (*RTI International is a trade name of Research Triangle Institute.) This publication was made possible through the Centers for Disease Control and Prevention (CDC) and the Association for Prevention Teaching and Research (APTR) Cooperative Agreement, No. U50/ CCU300860, Project TS The findings and conclusions in this publication are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention or the Association for Prevention Teaching and Research. Address correspondence and reprint requests to: Lauren A. McCormack, PhD, MSPH, RTI International, 3040 Cornwallis Road, P.O. Box 12194, RTP, NC 27709; phone: (919) ; fax: (919) ; <Lmac@rti.org>. an informed decision-making (IDM) process to make this decision. IDM implies that a person understands the choices he or she faces and the relative advantages and disadvantages of these choices. Although more than half of all men aged 50 or older in the United States have had one or more prostate-specific antigen (PSA) tests, 3 most men have little knowledge of the potential trade-offs of such screening and early detection. 4-9 For example, several studies show that men correctly answer only about 30% of knowledge questions about prostate cancer screening Fortunately, IDM interventions have been found to improve knowledge, accuracy of risk perceptions, or awareness about the advantages and disadvantages of screening and treatment options. 11,12 The results have been mixed whether knowledge reduces or increases the uptake of PSA screening, 6,13-16 although one meta-analysis 17 found that men who received decision aids were less likely to have a PSA. In the most recent metaanalysis, Volk and colleagues 12 reported that PSA decision aids appear to decrease interest in PSA testing and screening behavior among patients seeking routine care; the aids had no impact on screening behavior of patients seeking screening services. In general, certain patient characteristics appear to be associated with higher PSA screening levels, such as age, education, health insurance, and having a usual source of health care. 3,

2 Using a quasiexperimental design emphasizing differential messages, we examine the impact of presenting theorybased information about prostate cancer screening alone (PSA-Only intervention) or framed in the context of messages about other men s health interventions for which evidence is more certain (Men s Health intervention) on men s knowledge about and decisions regarding prostate cancer screening. We compare changes over time for both intervention groups with those of a control group. MATERIALS AND METHODS Interventions Theoretical and Cognitive Considerations People make medical decisions by considering the different choices with respect to their preferences and values. However, preferences are not stable and are often constructed by the elicitation process. 18 Framing effects are one of the most well-known factors influencing labile preferences. 19 The framing effect refers to the phenomenon in which subjects respond differently to equivalent verbal stimuli when the stimuli are worded differently. 19 We did not use message framing in the traditional sense; 20 rather we framed or casted the PSA messages which convey the uncertainty surrounding the PSA test in the context of other health practices with more certain evidence. We are not aware of any decision aids that have framed health messages in this way and in combination with the tenets of social cognitive theory to promote IDM. Social cognitive theory postulates that for a given human behavior, such as communicating about PSA-testing decisions, effective functioning requires both communicationrelated skills as well as the efficacy to use those skills well. 21 Studies have shown that behaviors can be enhanced by improving self-efficacy beliefs both through mastering skills and building confidence. In the intervention package for this study, we included specific components to enhance patients self-efficacy or confidence to make a decision and to communicate with their physician. Intervention Description and Formative Research Methods The intervention comprised an oral presentation by a physician followed by a question-and-answer session, a 20-minute video, a Web site, and print materials, including a trifold brochure, a 4 6-inch poster, and a shirt-pocket card decision aid, which have been described elsewhere. 22 We developed the content of the intervention by thoroughly reviewing existing PSA decision aids from as well as leading instruments that have examined PSA knowledge previously 23 and applying the project team s clinical experience and knowledge. The key messages reflected the evidence available at the time the interventions were developed (September 2004). 1 They conveyed the uncertainty surrounding the benefits of the test and early treatment, and the limited predictive ability of both the PSA test and pathological specimens collected from prostate biopsy. 1 Briefly, the key messages included the following: There are 2 types of prostate cancers: slow growing and fast growing. A problem with the PSA test is that it leads some men to get treatment that they do not need. About half of all men who get treatment for prostate cancer will have permanent side effects. Men should decide whether they feel the PSA test is right for them and talk with their doctors. In one version of the intervention, we framed the PSA messages within a men s health context (Men s Health group) based on prior research suggesting men had cognitive dissonance about PSA IDM messages 24 given the widespread perspectives. 25 In addition to prostate cancer screening information, we provided information about other health issues of interest to men, such as colorectal cancer screening and prevention of cardiovascular disease. We sought to convey 2 pieces of information that we hypothesized would influence beliefs about PSA testing and treatment. First, we provided incidence and mortality rates of prostate cancer relative to other common health problems, such as heart disease, stroke, and colorectal cancer. Second, we presented the differences in the certainty of medical information. The other version included information about PSA screening decisions only (PSA-Only group). Although this version contained more detail about prostate cancer issues, we presented the key messages in the same way in both versions. Using rigorous formative research methods and multiple rounds of pretesting, the project team developed a multicomponent intervention to give men information about deciding whether to have the PSA test. All pretesting and other data collection activities were Institutional Review Board (IRB)-approved. Study Design Using a snowball sampling approach, we recruited faithbased, fraternal, and fitness organizations (eg, YMCAs) in 2 North Carolina communities that had the capacity to host intervention sessions. The organizations received $250 for each session they hosted. We selected comparable communities using an in-depth comparison process involving sociodemographic and economic data 26 Community sites advertised our research sessions through informal channels and invited members of their organizations and the community to attend. Most who participated were organizational members. We delivered the study interventions to a convenience sample of 20 assemblages of men (ranging in size from 10 to 30) in the organizations and collected data from 11 assemblages in a third control community in North Carolina between September 2004 and February Journal of Cancer Education 2009, Volume 24, Number 3 239

3 Using a longitudinal design, we collected baseline data at each community-based session. Once project staff had administered baseline surveys, we delivered the intervention, lasting 45 minutes on average. Approximately 6 and 12 months later, we conducted follow-up interviews by mail (nonrespondents received telephone reminder calls and were given the option of completing the survey by telephone). Data collection was staggered over several months; thus, follow-up data collection periods ranged from 6 to 11 months and 12 to 18 months. Individual study participants received $10 for their time after completing each follow-up survey. To be eligible, men needed to be between 40 and 80 years of age and not previously diagnosed with prostate cancer. Outcome Measures We included 10 demonstrated-knowledge questions on the survey, based in part on Radosevich and colleagues, 23 that asked participants to demonstrate their knowledge of the contents of the interventions (an approach consistent with prior studies 27 ) (Table 1). We coded responses as correct or incorrect ( don t know as incorrect). Based on the number of items answered correctly, we computed a knowledge index score that ranged from 0 to 10. All 10 items were assessed at baseline and at the 6- and 12-month follow-ups. On the baseline and 12-month surveys, we asked men how long it had been since they had had a PSA test (Less than 12 months ago/1 or more years ago/never). Statistical Methods First, we examined the changes in each knowledge item in the knowledge index to allow us to determine the impact of the intervention on specific aspects of knowledge (hypotheses 1 and 2). We computed the percentage of respondents in each intervention group who answered each item correctly at baseline and at 6- and 12-month follow-ups. We used McNemar s test for significant group-level changes in the percentages of correct responses for both groups between baseline and the 2 later measurement points. We conducted logistic regression analyses controlling for percentages correct at baseline to test whether men who were exposed to either intervention were more knowledgeable than the control group (hypothesis 1), and whether men who received the information framed within a men s health context differed in their knowledge gain relative to those who received the PSA-Only intervention (hypothesis 2). Next, to explore predictors of knowledge index scores over time, we used generalized estimating equations (GEEs) 28 to control for intercorrelations within respondents across time. Although we recognize that it is not a primary outcome for IDM, we also investigated men s screening behavior 12 months after exposure, using logistic regression to examine which characteristics, including knowledge, were associated with the decision to get screened. RESULTS Sample Characteristics At the intervention sessions, a total of 584 eligible men took the baseline survey: 125 in the PSA-Only intervention group, 236 in the Men s Health intervention group, and 223 in the control group (approximately 4% of the sample [n = 35] was ineligible and deleted from the sample). Of those who participated in the baseline survey, 69% completed a 6-month follow-up survey, and 66% a 12-month follow-up survey. The intervention groups had higher response rates than the control group. By 12 months, 208 men had left the study, leaving a study sample of 376 men for the cohort analysis: PSA-Only group, 89; Men s Health group, 165; and control group, 122. a Baseline Knowledge Levels Table 1 displays the percentages of correct responses to 10 demonstrated-knowledge items for the 3 study groups. At baseline, knowledge was quite low on 3 items: (1) men over age 70 do not need a PSA test (6% correct); (2) the proportion of men who experience permanent side effects from treatment (10% correct); and (3) doctors do not know which treatment works best for early prostate cancer (16% correct). Knowledge about other test items ranged from 29% to 63%. Change in Knowledge After Exposure to the Intervention Across both intervention groups, knowledge increased significantly from baseline to the 12-month follow-up for most of the 10 items (Table 1); the exceptions were items about most prostate cancers being slow growing and having cancer even with a normal PSA for the PSA-Only group. For the control group, knowledge did not change significantly except for a significant decrease in awareness that men are most likely to die from heart attack and stroke. On almost all items, change in knowledge differed between the intervention and the control group. Thus, hypothesis 1 was supported. For the intervention groups, the magnitude of knowledge improvement ranged from about 13 percentage points (men having greater risk of dying from heart attack and stroke) to about 30 percentage points (men can live long, normal lives with slow-growing prostate cancer) over the study period. On one item (men can live long lives with slow-growing prostate cancer), the Men s Health group experienced a significantly greater increase in knowledge than the PSA-Only group. On the basis of the GEE modeling of the knowledge index score, the following factors were significantly associated with higher scores: higher education, being married, ever had a PSA test, excellent/very good self-reported health (versus fair/poor), and greater health literacy. Significantly lower knowledge scores were associated with being Black (versus White). 240 MCCORMACK et al. Prostate Cancer Knowledge

4 TABLE 1. Changes in Percentages of Correct Responses to Knowledge Questions From Baseline to 12-Month Follow-Up, by Study Group Knowledge question and number a (Correct answer in bold) All N = 376 PSA-Only N = 89 Men s Health N = 165 Control N = 122 Baseline 12 months Baseline 12 months Baseline 12 months Baseline 12 months Significant across at 12 (p < 0.05) 10. What are men most likely to die from? (Colon cancer/heart attack and stroke/ Prostate cancer) * 61 75** 67 55** M-C, P-C 1. Most prostate cancers are slow-growing. (True/False) 62 73*** *** M-C * Some men can have prostate cancer even if they have a normal PSA level. (True/False) 2. Men can live long, normal lives with slow-growing prostrate cancer. (True/False) 9. What are most common side effects of treatment? (Problems having an erection/ Problems with holding your urine/both of these/neither of these) 3. What kinds of cancer can PSA test find? (Slow-growing/Fast-growing/Both/Neither) 4. What can cause a high PSA test? (Prostate cancer/a big prostate w/no cancer/both of these/neither of these) 7. Which type of treatment for early prostate cancer works best? (Surgery/Radiation/ Work equally well/doctors don t know) 8. Out of 10 men, how many men who get treatment for prostate cancer will have permanent side effects? (0, 2, 5,10) 5. Doctors agree men over age 70 do not need a PSA test. (True/False) 52 73*** 65 93*** 42 72*** M-C, M-P, P-C 50 69*** 57 80** 40 68*** P-C 48 61*** 43 67** 45 63*** M-C, P-C 29 46*** 29 54*** 24 46*** P-C 16 30*** 18 34* 14 41*** M-C, P-C 10 22*** 13 31** 5 22*** M-C, P-C 6 20*** 1 24*** 7 24*** 7 10 M-C, P-C a Questions are ordered from most to least percentages correct in all respondents; numbers are shown in the order of placement on the survey. Note. Asterisks indicate significance of McNemar test comparing percentage of correct responses at baseline and 12-month follow-up: *P <.05; **P <.01; and ***P <.001. Logistic regression analyses were used to compare percentages of correct responses at 12 months for pairs of sites after controlling for baseline percentage of correct responses: C = control; M = Men s Health; and P = PSA-Only. The Cronbach s alphas of the indices were.68 at baseline,.71 at 6 months, and.70 at 12 months. 241

5 The interaction between time and study subgroups was significant, suggesting that knowledge changed differentially across the study sites (Figure 1). In particular, participants in the Men s Health intervention began the study with lower knowledge than the PSA-Only group (P <.001) and the control group (P =.001); at 12 months, however, they demonstrated knowledge levels similar to those of the PSA-Only group (P =.68), suggesting that the Men s Health group had overall greater knowledge gains. Both intervention groups had significantly greater increases in knowledge than the control group (Men s Health, P <.001; PSA-Only, P <.05). PSA Screening Decision at 12 Months At the 12-month follow-up, 65% of participants had had a PSA test within the previous 12 months (that they were aware of). The percentage of men in the PSA-Only group who were screened in the past 12 months was significantly higher than in both the Men s Health and control groups, but this differential was also present at baseline. When we compared how recently men were tested, we found no significant differences across time within study groups. Using logistic regression, we examined the factors associated with the probability of having a PSA test in the previous 12 months according to the 12-month survey data. Controlling for other factors, knowledge levels were not significantly associated with screening decisions (P =.08). The variable indicating whether men had talked to their doctor recently about the PSA test was a highly significant factor; those who had discussions were 15 times more likely to have been screened than those who did not have discussions. Several other factors were associated with a higher probability of being tested in the past year: older age, being in good (versus fair/poor) health, prior experience with Model-Adjusted Mean Knowledge Score FIGURE 1. Model-adjusted mean knowledge scores by time and study group Men's Health Control Prostate Only Baseline 6 Months 12 Months PSA testing, and greater decisional uncertainty. There were no significant differences across study groups. DISCUSSION Both versions of a community-based IDM intervention were successful in increasing knowledge about prostate cancer screening. Moreover, controlling for other factors, most knowledge was retained a year or more later. The findings of increased knowledge with both versions are consistent with knowledge increases reported in other studies. Of particular interest is the finding that men who received an intervention framing the PSA message within the context of messages about other men s health interventions had greater gains in knowledge than men who received the PSA-Only intervention. Much psychological research on clinical judgment and decision making has demonstrated that the medical decisions are significantly influenced by the way information is presented, such as whether it is presented qualitatively or quantitatively, how it is framed or the graphical representations used. 29 The intervention provided the PSA information relative to other reference points, that is, heart disease, stroke, and colon cancer. Casting messages in this way may have increased the ability to comprehend and retain the information over time; however, additional research is needed to support this hypothesis and to determine the impact of emphasizing increasing self-efficacy. Men may have also been more engaged by the Men s Health materials because of their relevance to them (even if they were not interested in prostate cancer screening) and, therefore, were more attentive. The additional detail provided about prostate cancer screening in the PSA-Only intervention may have made it more difficult for men to remember key facts. In item-specific analyses, knowledge levels were fairly low in several areas. Few men knew that doctors lacked knowledge of the best treatment for prostate cancer. If men do not recognize that the uncertainty about treatment options reflects the state of the science generally, then they are unlikely to understand that their values and preferences should play a role in choosing which treatment is best for them. This more general problem, which is true in much of medicine, poses a challenge to IDM quite apart from the specifics of prostate cancer screening and treatment. Men who were more knowledgeable were no more or less likely to have been screened in the past 12 months than those who were less knowledgeable, after controlling for interaction with their doctor. This could suggest that patient knowledge derived through a community intervention is less influential than that which is communicated during the clinical encounter. However, because one of the key messages of the intervention was to talk to your doctor, the intervention could be a contributing factor to the decision making process. Doctors recommendations are clearly important in influencing patients behaviors. 30 Further research is needed to assess what factors influence patient s 242 MCCORMACK et al. Prostate Cancer Knowledge

6 beliefs and behaviors and the proportion of providers who are currently promoting IDM. Community-based interventions that affect knowledge about prostate cancer screening and treatment have a role in educating the public at large and promoting IDM for individual patients. Part of the motivation for such work is the need for further development of IDM interventions in an era and context of consumer-driven health care and the context of patient-centered communication. Although this study focused on a screening decision because of the potential downstream effects it might have, IDM is equivalently important for many decisions involving options for medical treatments. Progress on numerous fronts is needed to make IDM as effective as possible for both patients and clinicians. Among the factors most in need of clarification is how best to frame messages. References 1. Harris R, Lohr KN. Screening for prostate cancer: an update of the evidence for the U.S. Preventive Services Task Force. 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