colorectal cancer screening mode preferences among us veterans

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Colorectal cancer screening mode preferences among US veterans Adam A. Powell a,b, , Diana J. Burgess a,b , Sally W. Vernon c , Joan M. Grifn a,b , Joseph P. Grill a , Siamak Noorbaloochi a,b , Melissa R. Partin a,b a Center for Chronic Disease Outcomes Research (CCDOR), Minneapolis Veterans Affairs Medical Center, Minneapolis, MN, USA b University of Minnesota Department of Medicine, Minneapolis, MN, USA c Division of Health Promotion and Behavioral Sciences, University of Texas-Houston, USA abstract article info Available online 8 September 2009 Keywords: Colorectal cancer screening Colonoscopy Fecal occult blood testing Patient preferences Objective. To assess colorectal cancer (CRC) screening mode preferences and correlates of these preferences among US veterans at average risk for CRC. Method. A cross-sectional survey of a nationally representative sample of VA patients was conducted between January 2005 and December 2006. We report preference distributions for screening modes among 2068 average-risk veterans and across patient subgroups based on personal, behavioral, and environmental factors. Independent predictors of preferences are identied through hierarchical logistic regression models. Results. Colonoscopy (37%) was the most preferred mode followed by fecal occult blood test (FOBT) (29%). The strongest predictors of preferences were previous screening experience, provider recommenda- tion, and use of non-VA healthcare services. Participants in higher socioeconomic groups were more likely to choose colonoscopy and less likely to indicate no preference. Conclusion. Screening programs that offer only one mode fail to accommodate the preferences of a substantial proportion of patients. Within the VA, adding screening colonoscopy to programs currently offering only FOBT is likely to increase preferences for colonoscopy, as patients incorporate provider recommendations for and personal experience with colonoscopy into their preferences. This is likely to disproportionately benet lower socioeconomic groups who do not currently have access to non-VA colonoscopy services. Published by Elsevier Inc. Introduction Colorectal cancer (CRC) is the second leading cause of cancer mortality (National Cancer Institute, 2006). Screening can reduce CRC mortality by 16%33% (Hardcastle et al., 1996; Kewenter et al., 1994; Kronborg et al., 1996; Mandel et al., 1993), and at the time of data collection for this study, the U.S. Preventive Services Task Force (2002) recommended screening using either fecal occult blood test (FOBT) annually, sigmoidoscopy or double-contrast barium enema every 5 years, or colonoscopy every 10 years. In 2003, FOBT constituted 90% of CRC screening within the VA (El- Serag et al., 2006), suggesting that few veterans were presented with other screening mode options. However, current VA policy species veterans be offered multiple screening modes (Perlin, 2005) and recent guidelines (Levin et al., 2008) recommend tests involving a structural exam of the colon (e.g., colonoscopy) be given priority over fecal tests because they are better able to identify pre-cancerous polyps. Many VA facilities are therefore working to create increased colonoscopy capacity (Powell et al., 2009). The primary goal of the current research is to quantify CRC screening mode preferences among a nationally representative sample of VA patients so that facilities are better able to project demand for colonoscopy. We also examine the relationship between preferences and personal (demographic, health, cognitive), environ- mental (social, medical care), and behavioral (past screening) factors derived from the theory of planned behavior (Ajzen, 1985) and social cognitive theory (Bandura, 2000). These can be used to enhance demand projections and provide insight into the processes by which preferences are derived. Methods Study population/sampling frame Male and female veterans, aged 5075 years, who had one or more primary care visits at a VA Medical Center in the past 2 years, were included. VA employees, deceased patients, and anyone enrolled in VA adult day care or nursing home facilities, or diagnosed with CRC, dementia, or Alzheimer's were excluded. To derive the study sample, the VA's 124 medical centers were grouped into 12 strata according to the size of the eligible patient population and the proportion of African-American patients within the site Preventive Medicine 49 (2009) 442448 Corresponding author. Center for Chronic Disease Outcomes Research (CCDOR), Minneapolis Veterans Affairs Medical Center, One Veterans Drive (111-0), Minneapolis, MN 55417, USA. Fax: +1 612 725 2118. E-mail address: [email protected] (A.A. Powell). 0091-7435/$ see front matter. Published by Elsevier Inc. doi:10.1016/j.ypmed.2009.09.002 Contents lists available at ScienceDirect Preventive Medicine journal homepage: www.elsevier.com/locate/ypmed

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Page 1: Colorectal cancer screening mode preferences among US veterans

Preventive Medicine 49 (2009) 442–448

Contents lists available at ScienceDirect

Preventive Medicine

j ourna l homepage: www.e lsev ie r.com/ locate /ypmed

Colorectal cancer screening mode preferences among US veterans

Adam A. Powell a,b,⁎, Diana J. Burgess a,b, Sally W. Vernon c, Joan M. Griffin a,b, Joseph P. Grill a,Siamak Noorbaloochi a,b, Melissa R. Partin a,b

a Center for Chronic Disease Outcomes Research (CCDOR), Minneapolis Veterans Affairs Medical Center, Minneapolis, MN, USAb University of Minnesota Department of Medicine, Minneapolis, MN, USAc Division of Health Promotion and Behavioral Sciences, University of Texas-Houston, USA

⁎ Corresponding author. Center for Chronic DiseaseMinneapolis Veterans Affairs Medical Center, One VeteraMN 55417, USA. Fax: +1 612 725 2118.

E-mail address: [email protected] (A.A. Powell).

0091-7435/$ – see front matter. Published by Elsevierdoi:10.1016/j.ypmed.2009.09.002

a b s t r a c t

a r t i c l e i n f o

Available online 8 September 2009

Keywords:Colorectal cancer screeningColonoscopyFecal occult blood testingPatient preferences

Objective. To assess colorectal cancer (CRC) screening mode preferences and correlates of thesepreferences among US veterans at average risk for CRC.

Method. A cross-sectional survey of a nationally representative sample of VA patients was conductedbetween January 2005 and December 2006. We report preference distributions for screening modes among2068 average-risk veterans and across patient subgroups based on personal, behavioral, and environmentalfactors. Independent predictors of preferences are identified through hierarchical logistic regression models.

Results. Colonoscopy (37%) was the most preferred mode followed by fecal occult blood test (FOBT)(29%). The strongest predictors of preferences were previous screening experience, provider recommenda-tion, and use of non-VA healthcare services. Participants in higher socioeconomic groups were more likely tochoose colonoscopy and less likely to indicate no preference.

Conclusion. Screening programs that offer only one mode fail to accommodate the preferences of asubstantial proportion of patients. Within the VA, adding screening colonoscopy to programs currentlyoffering only FOBT is likely to increase preferences for colonoscopy, as patients incorporate providerrecommendations for and personal experience with colonoscopy into their preferences. This is likely todisproportionately benefit lower socioeconomic groups who do not currently have access to non-VAcolonoscopy services.

Published by Elsevier Inc.

Introduction

Colorectal cancer (CRC) is the second leading cause of cancermortality (National Cancer Institute, 2006). Screening can reduce CRCmortality by 16%–33% (Hardcastle et al., 1996; Kewenter et al., 1994;Kronborg et al., 1996; Mandel et al., 1993), and at the time of datacollection for this study, the U.S. Preventive Services Task Force(2002) recommended screening using either fecal occult blood test(FOBT) annually, sigmoidoscopy or double-contrast barium enemaevery 5 years, or colonoscopy every 10 years.

In 2003, FOBT constituted 90% of CRC screening within the VA (El-Serag et al., 2006), suggesting that few veterans were presented withother screening mode options. However, current VA policy specifiesveterans be offered multiple screening modes (Perlin, 2005) andrecent guidelines (Levin et al., 2008) recommend tests involving astructural exam of the colon (e.g., colonoscopy) be given priority overfecal tests because they are better able to identify pre-cancerous

Outcomes Research (CCDOR),ns Drive (111-0), Minneapolis,

Inc.

polyps. Many VA facilities are therefore working to create increasedcolonoscopy capacity (Powell et al., 2009).

The primary goal of the current research is to quantify CRCscreening mode preferences among a nationally representativesample of VA patients so that facilities are better able to projectdemand for colonoscopy. We also examine the relationship betweenpreferences and personal (demographic, health, cognitive), environ-mental (social, medical care), and behavioral (past screening) factorsderived from the theory of planned behavior (Ajzen, 1985) and socialcognitive theory (Bandura, 2000). These can be used to enhancedemand projections and provide insight into the processes by whichpreferences are derived.

Methods

Study population/sampling frame

Male and female veterans, aged 50–75 years, who had one or moreprimary care visits at a VA Medical Center in the past 2 years, were included.VA employees, deceased patients, and anyone enrolled in VA adult day care ornursing home facilities, or diagnosed with CRC, dementia, or Alzheimer'swere excluded. To derive the study sample, the VA's 124 medical centerswere grouped into 12 strata according to the size of the eligible patientpopulation and the proportion of African-American patients within the site

Page 2: Colorectal cancer screening mode preferences among US veterans

443A.A. Powell et al. / Preventive Medicine 49 (2009) 442–448

(see Fig. 1). Two sites were then randomly selected from each stratum (24facilities) and a simple random sample of 156 individuals was selected fromeach sampled site (total sample=3744).

Data collection

This analysis uses data from a cross-sectional survey designed to examineveteran attitudes, beliefs and behaviors regarding colorectal cancer screening.Survey data were collected between January 2005 and December 2006.Surveys were initially mailed with a cover letter, postage-paid returnenvelope, and a $2 cash incentive, which has been found to encourageparticipation (Beebe et al., 2005). A reminder postcard was mailed after oneweek and a second survey (with no incentive) was sent to non-responderswithin 3–4 weeks of the first mailing. A minimum of six attempts were madeto administer the survey via phone for those who did not return thequestionnaire within three weeks of the second survey mailing. The surveyinstrument is available at http://www.hsrd.minneapolis.med.va.gov/PDF/SCREEN_NationalSurvey.pdf. The study protocol was approved by theMinneapolis VA Institutional Review Board.

Measures

The screening mode preference question was modeled after one used byLeard et al. (1997). Participants were asked to indicate “which colon cancertest would you most want to use if your doctor recommended you be testedfor colon cancer?” Response options were as follows: FOBT (fecal occult bloodtest), sigmoidoscopy, colonoscopy, DCBE (barium enema), “I would not wantto be tested,” and “don't know.” Participants who left this question blank(n=66) were categorized as “don't know.” Participants were given briefdescriptions of each CRC screening mode (Appendix A) developed for theNational Cancer Institute's colorectal cancer screening questionnaire (Vernonet al., 2004). We used these brief descriptions because most patients are not

Fig. 1. Subject flow diagram: United States, 2005–2006.

provided with detailed information on screening mode alternatives duringCRC screening discussions with providers (Ling et al., 2008). Therefore, ourapproach to eliciting preferences is similar to the approach used during time-constrained clinical encounters.

Demographic variables included race, education level, and income, allobtained from the survey, and age, obtained from administrative data. Healthfactors included overall health (obtained from the survey), CharlsonComorbidity Index score, and diagnoses of substance abuse and psychiatricdisorders (obtained from administrative data for 100% of the sample usingelectronic extraction algorithms). Behavioral factors included survey ques-tions on whether the participant had ever completed an FOBT or endoscopy(either colonoscopy or sigmoidoscopy).

Cognitive factors included CRC knowledge, determined by summingcorrect responses to two items drawn from prior literature (Manne et al.,2002; Rutten et al., 2007), one asking the appropriate age to initiate screening(correct=50), and the other asking participants to rate their agreement withthe statement that someone can have CRC without having symptoms(correct=“strongly agree” or “agree”). Additional cognitive factors includedfour scales developed by Vernon et al. (1997), namely Salience/Importance ofScreening (4 items, α=.89), Susceptibility to CRC (4 items, α=.76),Perceived Efficacy of Screening (2 items, α=.65), and Screening Self-efficacy(4 items, α=.80), and two scales developed by the study team, namely TestResult Anxiety (2 items, α=.78) and Endoscopy Anxiety (5 items, α=.86).Social environmental factors included marital status and Social Influence (4items, α=.69) (Vernon et al., 1997). Medical care support factors includedsurvey-reported use of non-VA care and physician recommendation for FOBTand for colonoscopy in the past year. All scales were dichotomized prior toanalysis by assigning the value 0 to all scores at or below the median and 1 toall scores above the median. Scale items are provided in Appendix B.

Analysis

A total of 3025 patients completed the survey (response rate=81%). Ofthese, 961 patients were high risk (family history of CRC or a personal historyof polyps, or inflammatory bowel disease) and were excluded becauseguidelines specify colonoscopy is the only appropriate testing mode for thissubgroup. The remaining 2068 average-risk participants were included in allanalyses.

We report preferences overall and by subgroups. Estimates wereweighted to account for oversampling and stratification in our samplingplan. Because few participants chose sigmoidoscopy or barium enema, wecombined these two modes in subgroup analyses. χ2 Statistics were used totest for differences in preferences across subgroups.

To identify independent correlates of the three most commonly chosenscreening mode preference response categories, three logistic regressionanalyses were performed predicting: (1) preference for colonoscopy versusall other responses, (2) preference for FOBT versus all other responses, and(3) no expressed preference versus all other responses. Each model includeda random effect for facility to account for the possible interdependence ofpatients within each site. In order to retain participants with missing data forone or more of the independent variables included in our multivariatemodels, we employed multiple imputation techniques to generate values formissing data (Little and Rubin, 2003). Eachmodel was created ten times usingthe imputed data sets, and parameters were constructed using averages of theestimates derived from these imputed datasets. All analyses were run usingSAS version 9.1 (SAS Institute Inc., Cary, NC).

Results

As shown in Table 1, participants were predominately male (96%),aged 50 to 64 years (61%), and white (72%). Forty-six percent had nocollege education and 39% had an income of $20,000 or less.Participants indicated good overall health and the average CharlsonComorbidity Index was 1.9; however, 50% had a psychiatric diagnosisand 39% had a substance abuse diagnosis documented in theirmedicalrecord. Seventy-two percent had completed an FOBT and 58% hadcompleted an endoscopy in the past.

As shown in Fig. 2, the most commonly chosen screening modewas colonoscopy (37%), followed by FOBT (29%). Most participantsthat did not chose one of these two modes indicated that they did not

Page 3: Colorectal cancer screening mode preferences among US veterans

Table 1Characteristics of national sample of VA patients—percent distribution or mean scalescores (N=2068): United States, 2005–2006.

Characteristic Statistic

DemographicsGender—male 96.3Age (years)50–64 61.165–75 38.9

Race/ethnicityWhite 72.1Black 14.3Other 13.6

EducationHigh school or less 46.2Some college 35.7College graduate 18.1

Income$20,000 or less 39.0$20,001 to $40,000 32.7$40,001 or more 28.3

Health factorsOverall health (mean)a 3.3Charlson Comorbidity Index (mean) 1.9Had psychiatric diagnosis 49.8Had substance abuse diagnosis 38.5

Cognitive factorsCRC knowledge (mean)b 1.2Salience/importance (mean)c 4.1Susceptibility (mean)c 2.6Efficacy of screening (mean)c 4.0Test result anxiety (mean)c 2.5Endoscopy anxiety (mean)c 2.7Screening self-efficacy (mean)c 3.7

Social environmental factorsMarried 58.7Screening social influence (mean)c 3.5

Medical care Support support factorsReceives all healthcare at VA 36.2Physician recommended FOBT 55.4Physician recommended colonoscopy 27.8

Behavioral factorsEver completed FOBT 71.7Ever completed endoscopy 58.2

CRC=colorectal cancer.a Scale: 1 (poor) to 5 (excellent).b Number correct; range: 0 to 2.c Scale: 1 (low) to 5 (high).

444 A.A. Powell et al. / Preventive Medicine 49 (2009) 442–448

know which mode they preferred or left the question blank (22%).Only 4% indicated that they did not want to be tested and fewidentified sigmoidoscopy and barium enema as their preferred mode.

As shown in Table 2, subgroups that preferred colonoscopy wereolder (41.8% vs 34.9%), white (40.1% vs 32.1%), college graduates

Fig. 2. Colorectal cancer screening mode preference di

(45.8% vs 35.4%), with incomes greater than $20,000 (27.5% vs 44.2%).Younger veterans were more likely than older participants to preferFOBT (32.3% vs 24.1%). The largest differences favoring colonoscopy(N20%) were found for individuals who had an endoscopy in the past(52.2% vs 19.1%), received a recommendation for a colonoscopy fromtheir physician (54.0% vs 31.8%), had high screening self-efficacy(51.5% vs 25.3%), had low endoscopy anxiety (49.5% vs 24.0%), andwho considered CRC screening to be important (50.2% vs 26.6%). Thelargest differences favoring FOBT were found among participants whohad not completed an endoscopy in the past (40.9% vs 20.1%), withhigh endoscopy anxiety (37.9% vs 21.7%), with a physician recom-mendation for FOBT (36.7% vs 20.6%), and without a recommendationfor colonoscopy (33.0% vs 18.5%).

Multivariate models predicting preferences are shown in Table 3.Participants with no college education and participants with anincome of $20,000 to $40,000weremore likely to choose colonoscopy.Older participants were less likely to choose FOBT. Blacks were lesslikely to choose FOBT and more likely to have no expressedpreference. Those in better health were more likely to prefercolonoscopy. High perceived importance of screening, high perceivedsusceptibility to CRC, and low endoscopy anxiety predicted preferencefor colonoscopy. Participants with high test result anxiety and lowscreening self-efficacy scores were less likely to prefer colonoscopyandmore likely to have no preference. Only one cognitive factor (highendoscopy anxiety) was an independent predictor of preference forFOBT (OR 1.69, 95% CI 1.41–2.01). No social environmental factorswere predictive of preferences. Participants who received a physicianrecommendation for a colonoscopy or who had used non-VA serviceswere more likely to prefer colonoscopy and less likely to prefer FOBTor have no expressed preference. Participants who received aphysician recommendation for FOBT were more likely to preferFOBT. Participants who had previously completed an FOBT were morelikely to prefer FOBT and less likely to have no preference. Similarly,those who had previously completed an endoscopy were both morelikely to prefer colonoscopy and less likely to have no preference.

Discussion

This study examined the distribution of CRC screening modepreference in a large, nationally representative sample of VA patientsand drew upon established theoretical frameworks to identifypredictors of these preferences. Our finding that most participantsindicated a preference for either colonoscopy (37%) or FOBT (29%) isconsistent with other studies indicating a fairly even preferencedistribution between these two modes of screening (Debourcy et al.,2008; Hawley et al., 2008; Janz et al., 2007; Leard et al., 1997; Ling etal., 2001). Schroy et al. (2007) found that nearly three times as manyparticipants preferred colonoscopy than FOBT. However, this study

stribution (N=2068): United States, 2005–2006.

Page 4: Colorectal cancer screening mode preferences among US veterans

Table 2Distribution of colorectal cancer screening mode preferences by subgroups (N=2068): United States, 2005–2006.

Prefer colonoscopy Prefer FOBT Prefer othermode

No expressedpreference

Don't want tobe tested

DemographicsAge (years)50–64 34.9⁎⁎ 32.3⁎⁎ 8.1 22.3 2.4⁎⁎65–75 41.8⁎⁎ 24.1⁎⁎ 7.3 21.0 5.8⁎⁎

Race/ethnicityWhite 40.1⁎⁎ 29.5 7.1 19.7⁎⁎ 3.7Black 31.8⁎⁎ 27.6 9.6 27.8⁎⁎ 3.2Other 32.4⁎⁎ 31.6 8.7 23.5⁎⁎ 3.8

EducationHigh school or less 35.4⁎⁎ 29.8 6.2 24.2 4.5⁎Some college 35.5⁎⁎ 30.2 8.3 22.3 3.8⁎⁎College graduate 45.8⁎⁎ 27.0 10.5 15.4 1.2⁎

Income$20,000 or less 27.5⁎⁎ 32.8 10.0⁎ 25.2⁎⁎ 4.6⁎$20,001 to $40,000 41.6⁎⁎ 29.1 5.2⁎ 20.9⁎⁎ 3.2⁎$40,001 or more 47.1⁎⁎ 24.7 7.5⁎ 18.0⁎⁎ 2.7⁎

Health factorsOverall healthPoor to average 30.5⁎⁎ 32.1⁎ 8.1 25.1⁎ 4.2Good to excellent 42.4⁎⁎ 27.4⁎ 7.6 19.4⁎ 3.2

Charlson Comorbidity index scoreCCI=0 41.3⁎⁎ 27.4 7.1 20.9 3.3CCI=1 37.7⁎⁎ 32.4 6.9 20.3 2.7CCIb1 34.5⁎⁎ 29.1 8.8 23.3 4.3

Psychiatric diagnosisNo 39.8⁎ 27.8 7.9 20.7 3.9Yes 35.1⁎ 31.0 7.8 22.8 3.3

Substance abuse diagnosisNo 41.9⁎⁎ 26.8 7.2 20.6 3.5Yes 30.6⁎⁎ 33.3 8.7 23.7 3.8

Cognitive factorsCRC knowledge0 correct answers 31.2⁎⁎ 28.0 8.3 27.8⁎⁎ 4.71 correct answer 34.6⁎⁎ 29.4 9.0 23.2⁎⁎ 3.82 correct answers 44.1⁎⁎ 30.1 5.9 17.1⁎⁎ 2.9

Salience/importanceLow 26.6⁎⁎ 33.6⁎⁎ 6.6 27.0⁎⁎ 6.2⁎⁎High 50.2⁎⁎ 24.4⁎⁎ 9.3 15.6⁎⁎ 0.5⁎⁎

SusceptibilityLow 34.5 32.2⁎⁎ 7.8 19.9 5.6⁎⁎High 40.0 26.9⁎⁎ 7.8 23.6 1.7⁎⁎

Efficacy of screeningLow 32.1⁎⁎ 32.0⁎⁎ 7.7 24.4⁎⁎ 3.9High 50.7⁎⁎ 22.8⁎⁎ 8.2 15.4⁎⁎ 2.9

Test result anxietyLow 44.7⁎⁎ 27.2 8.0 16.9⁎⁎ 3.0High 31.4⁎⁎ 31.2 7.6 25.8⁎⁎ 4.1

Endoscopy anxietyLow 49.5⁎⁎ 21.7⁎⁎ 9.6⁎ 16.6⁎⁎ 2.5⁎High 24.0⁎⁎ 37.9⁎⁎ 5.8⁎ 27.6⁎⁎ 4.8⁎

Screening self-efficacyLow 25.3⁎⁎ 33.8⁎⁎ 7.1 28.0⁎⁎ 5.7⁎⁎High 51.5⁎⁎ 24.2⁎⁎ 8.6 14.5⁎⁎ 1.2⁎⁎

Social environmental factorsMarital statusSingle 31.8⁎⁎ 31.1 9.3⁎ 24.6⁎⁎ 3.2Married 41.9⁎⁎ 28.1 6.6⁎ 19.5⁎⁎ 3.9

Screening social influenceLow 29.2⁎⁎ 34.4⁎⁎ 6.8⁎ 24.7⁎⁎ 4.9⁎⁎High 47.6⁎⁎ 23.2⁎⁎ 9.0⁎ 18.2⁎⁎ 2.0⁎⁎

Medical care support factorsHealthcare system useReceives only VA care 25.3⁎⁎ 35.1⁎⁎ 7.7 27.0⁎⁎ 4.9⁎⁎Receives non-VA care 44.7⁎⁎ 25.9⁎⁎ 7.9 18.6⁎⁎ 2.8⁎⁎

Physician recommendation of FOBTNo 43.5⁎⁎ 20.6⁎⁎ 8.7 23.8 3.5Yes 32.3⁎⁎ 36.7⁎⁎ 7.1 20.2 3.7

Physician recommendation of colonoscopyNo 31.8⁎⁎ 33.0⁎⁎ 8.1 23.9⁎⁎ 3.1Yes 54.0⁎⁎ 18.5⁎⁎ 7.0 15.3⁎⁎ 5.1

Behavioral factorsEver completed FOBTNo 36.1 21.5⁎⁎ 7.5 28.6⁎⁎ 6.3⁎⁎Yes 37.9 32.9⁎⁎ 7.9 18.8⁎⁎ 2.4⁎⁎

(continued on next page)

445A.A. Powell et al. / Preventive Medicine 49 (2009) 442–448

Page 5: Colorectal cancer screening mode preferences among US veterans

Table 2 (continued)

Prefer colonoscopy Prefer FOBT Prefer othermode

No expressedpreference

Don't want tobe tested

Ever completed endoscopyNo 19.1⁎⁎ 40.9⁎⁎ 7.1 27.7⁎⁎ 5.2⁎⁎Yes 52.2⁎⁎ 20.1⁎⁎ 8.4 17.0⁎⁎ 2.3⁎⁎

Significance tests conducted using χ2 tests of difference in the proportion of participants choosing the column response option.FOBT=fecal occult blood test, CCI=Charlson Comorbidity Index, VA=United States Veteran's Affairs Healthcare System.⁎ pb .05.⁎⁎ pb .01.

446 A.A. Powell et al. / Preventive Medicine 49 (2009) 442–448

included stool DNA testing in the screening options. When prefer-ences for all stool tests are combined, results are similar to ourfindings (46% preferring stool tests and 52% preferring colonoscopy).Three studies report a majority preferring FOBT. However, each ofthese studies consisted of very different samples than the US veteranssurveyed in our research. Almog et al. (2008) surveyed Israeli HMOmembers, Wolf et al. (2006) surveyed members of a New Yorkhealthcare workers union, and Nelson and Schwartz (2004) surveyeda convenience sample of adults aged 18 to 54 years, most of which hadno previous CRC screening experience.

Physician recommendation and previous screening behaviorexplained the most variance in our multivariate models. Otherstudies have identified physician recommendation as an importantpredictor in CRC screening compliance (Bejes and Marvel, 1992;Lemon et al., 2001; Myers et al., 1990; Seeff et al., 2004; Wee et al.,2005; Zapka et al., 2002). One implication of these findings is that, assites expand their offerings, preferences are likely to evolve. Withinthe VA, if sites that currently offer only FOBT introduce colonoscopyinto their screening program, one could expect physician colono-

Table 3Multivariate odds ratios (OR) and 95% confidence intervals (CI) from hierarchical logistic rUnited States, 2005–2006.

Prefer colonoscopy vs. Anyother response, OR (95% CI)

DemographicsAged 65+ 0.89 (0.74–1.07)Race black (vs. white) 0.83 (0.63–1.10)Race other (vs. white) 0.77 (0.51–1.16)Some college (vs. high school or less) 0.79 (0.64–0.99)College graduate (vs. high school or less) 1.01 (0.68–1.52) )Income $20,000 to $40,000 (vs $20,000 or less) 1.46 (1.11–1.91)Income $40,000 or more (vs $20,000 or less) 1.29 (0.97–1.70)

Health factorsOverall health good to excellent 1.30 (1.01–1.68)CCI=0 (vs CCI=2) 1.25 (0.87–1.80)CCI=1 (vs CCI=2) 1.16 (0.86–1.57)Had psychiatric diagnosis 1.00 (0.69–1.43)Had substance abuse diagnosis 1.00 (0.69–1.45)

Cognitive factorsKnowledge moderate (vs low) 1.01 (0.67–1.52)Knowledge high (vs low) 1.30 (0.94–1.80)High salience/importance 1.48 (1.07–2.04)High susceptibility 1.30 (1.13–1.50)High efficacy of screening 1.15 (0.93–1.41)High test result anxiety 0.77 (0.61–0.96)High endoscopy anxiety 0.57 (0.42–0.77)High screening self-efficacy 1.53 (1.21–1.94)

Social environmental factorsMarried 1.05 (0.78–1.41)High screening social influence 1.38 (0.95–2.00)

Medical care support factorsReceived non-VA care 2.10 (1.59–2.76)Dr recommended FOBT 0.74 (0.52–1.07)Dr recommended colonoscopy 2.32 (1.57–3.43)

Behavioral factorsEver completed FOBT 1.05 (0.66–1.67)Ever completed endoscopy 2.88 (2.06–4.02)

Bold represents statistically significant results, pb0.05.FOBT=Fecal Occult Blood Test, CCI=Charlson Comorbidity Index, VA=United States Vete

scopy recommendations and colonoscopy procedures to increase.This is likely to result in a higher proportion of veterans preferringcolonoscopy and fewer preferring FOBT or having no preference(both of which were associated with not having received acolonoscopy recommendation).

The finding that several cognitive factors were importantindependent correlates of preference, especially preference forcolonoscopy, is consistent with other studies indicating that colono-scopy tends to be preferred among those who place a relatively highvalue on test accuracy (Hawley et al., 2008; Marshall et al., 2007;Wolfet al., 2006; Ling et al., 2001) and are less concerned with discomfortassociated with the test (Janz et al., 2007; Ling et al., 2001). Only onecognitive variable was a significant independent predictor ofpreference for FOBT (high endoscopy anxiety). Cognitive variablesmay bemore relevant to the choice of colonoscopy than FOBT becauseof the greater involvement and commitment associated withpreparing for and undergoing a colonoscopy.

We found that preference for colonoscopy was higher among vete-rans that are white, higher income, college graduates, married, in better

egressions predicting preference for colonoscopy and preference for FOBT (N=2068):

any Prefer FOBT vs. any otherresponse, OR (95% CI)

No expressed preference vs.any other response, OR (95% CI)

0.80 (0.65–0.98) 1.15 (0.79–1.68)0.80 (0.68–0.94) 1.48 (1.03–2.11)1.03 (0.72–1.48) 1.22 (0.96–1.55)1.14 (0.71–1.82) 0.80 (0.51–1.24)0.92 (0.54–1.55) 0.98 (0.57–1.68)0.90 (0.66–1.23) 1.20 (0.83–1.75)0.77 (0.57–1.06) 1.06 (0.89–1.26)

0.92 (0.76–1.12) 0.87 (0.72–1.04)0.99 (0.69–1.41) 0.89 (0.52–1.51)1.13 (0.70–1.81) 0.83 (0.58–1.20)0.97 (0.69–1.36) 0.97 (0.66–1.42)0.98 (0.71–1.36) 1.12 (0.93–1.34)

1.26 (0.80–1.98) 0.82 (0.55–1.22)1.35 (0.99–1.86) 0.68 (0.47–1.00)0.94 (0.78–1.13) 0.78 (0.61–1.00)0.81 (0.66–1.00) 1.22 (0.89–1.67)0.88 (0.68–1.14) 0.83 (0.63–1.11)0.92 (0.69–1.21) 1.35 (1.00–1.82)1.69 (1.41–2.01) 1.24 (0.77–1.98)1.06 (0.77–1.45) 0.64 (0.47–0.88)

1.06 (0.87–1.29) 0.89 (0.65–1.23)0.74 (0.54–1.02) 0.89 (0.71–1.11)

0.74 (0.56–0.97) 0.68 (0.50–0.93)1.76 (1.30–2.38) 0.79 (0.43–1.45)0.53 (0.36–0.78) 0.65 (0.48–0.86)

1.70 (1.26–2.29) 0.64 (0.48–0.86)0.49 (0.38–0.64) 0.73 (0.52–1.03)

ran's Affairs Healthcare System.

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health, and users of non-VA healthcare. Debourcy et al. (2008) foundthat variables reflecting higher socioeconomic status (SES) wereassociated with greater preference for colonoscopy and less preferencefor FOBT. In our study, there was little difference in the appeal of FOBTacross SES subgroups. Instead, subgroup differences in preference forcolonoscopy tended to be offset by corresponding differences in thepercent indicating no preference. One possible explanation for this isthat both high and low SES subgroups have enough of an understandingof FOBT to form an opinion about this mode, but low SES groups havehad less exposure to colonoscopy information. This is consistent withthe fact thatmanyveteranswithout access to non-VA services have onlybeen offered FOBT. If provided with information about and theopportunity to undergo screening colonoscopy, lower SES subgroupsmay express preferences more similar to their higher SES counterparts.Those without access to non-VA healthcare resources are also mostlikely to benefit from expansion of VA screening programs to includecolonoscopy.

Limitations

We provided patients with less detail on the screening modeoptions than provided in many other studies. A fully informeddecision may require an assessment of each mode's sensitivity,specificity, risk profile, convenience, recommended frequency, andout-of-pocket costs. Previous research on CRC screening modepreferences indicates that information about out-of-pocket costs(Griffith et al., 2008) can affect preferences. However, VA patients donot incur co-payments for any CRC screeningmodes (U.S. Departmentof Veteran Affairs, 2008). The fact that 22% of our sample expressed nopreference suggests some patients may needmore information beforemaking a choice. However, our work may better reflect patients'understandings of their options when faced with real CRC screeningdecisions in a busy clinic.

This study only offered participants screening mode options thatwere guideline endorsed at the time of data collection (U.S. PreventiveServices Task Force, 2002). Newly published guidelines also includeCT colonography and fecal DNA testing in their options (Levin et al.,2008). These screening modes have a unique configuration of costsand benefits that appeal to some patients (Hawley et al., 2008; Schroyet al., 2007). Currently, however, these tests are not widely availablewithin the VA.

Afinal limitation of this research is that because our sample includedonly VA patients, findings may not generalize to other populations.Many participants in our studyhad previous experiencewith FOBT and/or endoscopy. One might expect different preference distributionsamong populations with different prior screening experiences.

Conclusion

Screening programs that offer only one mode fail to accommodatethe preferences of a substantial proportion of patients. Within the VA,adding screening colonoscopy to programs currently offering onlyFOBT is likely to increase preferences for colonoscopy as patientsincorporate provider recommendations for and personal experiencewith colonoscopy into their preferences. This may disproportionatelybenefit lower socioeconomic groups who do not currently have accessto non-VA colonoscopy services.

Conflict of interest statementThe authors have no conflicts of interest regarding the submission and publication ofthe manuscript.

Appendix A. Supplementary data

Supplementary data associated with this article can be found, inthe online version, at doi:10.1016/j.ypmed.2009.09.002.

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