Vol. 12, 651–655, July 2003 Cancer Epidemiology, Biomarkers & Prevention 651 Short Communication The Effects of Colorectal Cancer Screening on Health Attitudes and Practices1 Anne Miles, Jane Wardle,2 Kirsten McCaffery, Again, the association between screening outcome and smoking Sara Williamson, and Wendy Atkin behavior only approached significance. Cancer Research UK Health Behavior Unit, Department of Epidemiology and Public Health, University College London, London WC1 6BT, United Materials and Methods Kingdom [A. M., J. W., K. M., S. W.], and Cancer Research UK Colorectal Cancer Unit, St. Mark’s Hospital, Harrow, United Kingdom [W. A.] In this study, we evaluated attitudes toward and practice of health behaviors before and after screening in a large sample of adults attending for CRC4 screening as part of the United The purpose of this study is to establish whether a negative Kingdom FS Trial. Participants were a population sample of screening result leads to complacency about health and poorer average-risk adults ages 55–64 years, identified from Family health practices. Participants were 3535 older adults, ages Health Services Authority registers for participating general 55–64 years, taking part in the United Kingdom Flexible Sig- practices (primary health care in the United Kingdom) in 14 moidoscopy Trial. They were sent postal questionnaires before centers across the United Kingdom. Local research ethics ap- and after screening attendance. Eating fruit and taking exercise proval was obtained for each of the participating centers. Those were both rated as more important after screening than before, eligible for inclusion in the trial were written to by their general whereas ratings for the importance of avoiding fatty foods and practitioner with an information leaflet on CRC and FS screen- attending cervical and breast cancer screening did not change. ing and were asked whether, if invited, they would accept the Fruit and vegetable intake increased, exercise increased, and offer of screening. The information leaflet described the aims of smoking rates decreased from before to after screening. FS screening as the detection and removal of premalignant Changes in diet, exercise, and smoking were not significantly polyps and did not refer to possible causes of CRC. The leaflet related to screening outcome. These findings provide reassur- was received before the prescreening questionnaire. Respon- ance that screening does not lead to a less healthy lifestyle in dents who replied saying they were interested in screening were the short term and could be used as a context in which to randomly allocated to screening or usual care. The design of the promote positive health behavior change. main FS trial has been described elsewhere (4). Screening outcomes were described as negative when ei- Introduction ther no pathological specimens were detected or when patho- Complacency about health, leading to deterioration in health logical analysis of specimens showed no significant pathology behaviors, has been hypothesized to represent an undesirable (65%); lower risk when the pathology detected was considered Ͻ consequence of negative screening results (1). However, sur- minor [e.g., 1–2 small adenomatous polyps ( 1 cm) with a Ͻ prisingly few studies have investigated the impact of screening tubular histology and mild to moderate dysplasia or 20 on health behaviors. The specter of adverse behavioral effects hyperplastic polyps; 30%]; and higher risk when 3 or more was raised in the Telemark Study when the results showed adenomas or 20 or more hyperplastic polyps were detected, or trends toward “improvement in smoking category”3 and greater significant pathology was found (e.g., adenomatous polyps Ͼ body mass index gains in the group who had a negative flexible that were either large ( 1 cm) or had tubulovillous or villous sigmoidoscopy screening result compared with those who had histology or severe dysplasia; 5%), and a colonoscopy polyps detected (2), although neither effect was statistically was recommended (see Ref. 5 for additional details). Those significant. Lower smoking cessation and smoking reduction eligible to receive the postscreening questionnaire were people rates were also observed in a small group of older adult smokers who had attended FS screening (and colonoscopic screening, if who had received a clear computed tomography scan for early- recommended) and who had received a nonmalignant screening stage lung cancer compared with those receiving an abnormal outcome. result (3), although both groups had higher than expected quit Health attitudes and behaviors were assessed by question- ϭ rates, and the results were interpreted as showing that screening naire in a randomly selected subset (n 5942) of the individ- participation was a catalyst to positive health behavior change. uals in the screening arm of the trial in trial centers in Oxford, Portsmouth, and Swansea. Questionnaires were sent before the screening appointment and 3 months after screening. The atti- tude items were based on the measures used in the European Received 3/21/03; revised 3/21/03; accepted 4/22/03. Health Survey (6) and were as follows: “in general, how im- The costs of publication of this article were defrayed in part by the payment of portant do you feel the following health measures are? to avoid page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. fatty foods; to eat plenty of fruit; to take regular exercise; for 1 Support from Cancer Research UK, the Medical Research Council, and NHS women to have a cervical smear test at least every 5 years; for R&D funding are gratefully acknowledged. 2 To whom requests for reprints should be addressed, at Cancer Research UK Health Behavior Unit, Department of Epidemiology and Public Health, Univer- sity College London, London WC1 6BT, United Kingdom. Phone: ϩ44 (0) 20 7679 6627; Fax: ϩ44 (0) 207813 2848; E-mail: [email protected]. 4 The abbreviations used are: CRC, colorectal cancer; FS, Flexible Sigmoidos- 3 From smoking Ͼ10 cigarettes/day to Ͻ10 cigarettes/day. copy; CI, confidence interval. Downloaded from cebp.aacrjournals.org on September 27, 2021. © 2003 American Association for Cancer Research. 652 Short Communication: Effects of Screening on Health Behavior women to have a breast screen (mammogram) at least every of the postscreening questionnaire in the higher risk outcome 3 years?” group. This resulted in an addition of 234 cases, putting the Health behaviors were assessed as follows: “about how overall response rate up marginally to 63% but did not alter the many servings of fruit do you eat (fresh, frozen or canned)”, pattern of results so will not be discussed further. “about how many servings of vegetables do you eat (including The effect of screening outcome on continuous variables salad but excluding potatoes),”“do you take regular exercise was assessed using repeated measures ANOVA, with time each week,” and “do you smoke cigarettes at all nowadays” (all (pre- versus postscreening) as the within-subjects variable and items from Ref. 6; Table 1). Response options for each question outcome group and gender as between-subjects variables. A are shown in the table footnote. significant group-by-time interaction was taken as evidence for Demographic details were also collected. differences in behavior change after screening. The effect of screening outcome on the binary variables was assessed using Results logistic regression with prescreening health behavior scores, gender and screening outcome as the predictors, and post- A total of 4644 of 5942 (78%) of prescreening questionnaires screening health behavior scores as the dependent variable. were returned. A total of 4329 (73%) of those invited, attended Change over time was assessed in the continuous variables by screening, of whom 3789 had completed the prescreening ques- examining the main effect of time within the ANOVAs and in tionnaire. Of the latter, 20 were not eligible for follow-up, either the binary variables with conditional logistic regression. because they were diagnosed with cancer (n ϭ 16), or they did ϭ Ͻ Eating fruit [F(13,440) 33.9, P 0.001] and taking not have a colonoscopy (n ϭ 4; Fig. 1). The response rate for ϭ Ͻ exercise [F(13,422) 53.3, P 0.001] were rated as more the postscreening questionnaire among attenders who had com- important after screening than before, but ratings for the im- pleted the prescreening questionnaire was high (93%; 3535 of portance of avoiding fatty foods and attending cervical and 3769), although slightly lower in the higher risk outcome group breast cancer screening did not change. There were no signif- ␹2 ϭ ϭ (85%) than the other groups (both 94%; 27.0, df 2, icant interactions with screening outcome group. P Ͻ 0.001). ϭ Fruit and vegetable intake increased [F(13,445) 41.4, Overall, 60% of those originally invited to participate in Ͻ ϭ Ͻ P 0.001; F(13,435) 17.5, P 0.001] exercise increased this study completed both questionnaires and attended screen- (odds ratio: 1.91; 95% CI: 1.62–2.25; P Ͻ 0.001), and smoking ing (3535 of 5942), and they are referred to here as completers. rates decreased (odds ratio: 0.67, 95% CI: 0.46–0.98, The limited demographic information on the full sample shows P ϭ 0.04) from before to after screening (Table 1). There was a higher percentage of men than women completed the study no evidence that change in health behavior related to screening (61 versus 58%), but there was no difference in age between outcome. Fruit intake and vegetable intake showed no time completers and noncompleters. Additional information was Ͻ by screening outcome interaction [F(23,445) 1, ns and available on those who had filled out the prescreening ques- Ͻ F(23,435) 1, ns, respectively]. Exercise status did not vary by tionnaire, showing that completers were less socioeconomically screening outcome, controlling for pre-screening exercise deprived (indexed by educational qualifications and car and (Wald ϭ 0.38, df ϭ 2, ns).