Alimentary Pharmacology & Therapeutics
Determinants of compliance with colonoscopy in patients with adenomatous colon polyps in a veteran population A. A. SIDDIQUI*, A. PATEL* & S. HUERTA
*Division of Gastroenterology, VA North Texas Health Care System and University of Texas Southwestern Medical School, Dallas, TX, USA; Division of GI/Endocrine Surgery, VA North Texas Health Care System and University of Texas Southwestern Medical School, Dallas, TX, USA Correspondence to: Dr A. A. Siddiqui, Division of Gastroenterology, VA North Texas Health Care System (111B1), 4500 S. Lancaster, Dallas, TX 75216, USA. E-mail:
[email protected]
Publication data Submitted 22 August 2006 First decision 25 September 2006 Resubmitted 2 October 2006 Accepted 4 October 2006
SUMMARY Aim To determine factors affecting compliance of a follow-up colonoscopy in patients with previously diagnosed adenomatous colon polyps. Methods A retrospective review was performed on patients with adenomatous polyps excised between January and December 1998. Twenty-nine clinical factors were assessed in patients grouped into whether they were compliant (n ¼ 81) or noncompliant (n ¼ 38) with follow-up colonoscopy. Significant variables by univariate analysis were included in multivariate regression. Results One hundred and nineteen patients with adenomatous colon polyps were identified. Of 119 patients, 114 had a documented recommendation for follow-up of 5 years or less, with 69% having been compliant. In a univariate analysis, greater number of polyps (P ¼ 0.04), NSAID use (P ¼ 0.02), statin use (P ¼ 0.005), first-degree relatives with colon cancer (P ¼ 0.05) and compliance with out-patient clinic follow-up (P < 0.001) were significantly associated with patient compliance. Multivariate analysis revealed statin use (P ¼ 0.05), first-degree relatives with colon cancer (P ¼ 0.06) and compliance with out-patient clinic follow-up (P < 0.001) were independent predictors of compliance. Conclusions History of statin use and family history of colon cancer are good predictors of compliance. The strongest predictor can be anticipated with compliance assessed with encounters for other visits. Strong efforts should be directed at improving patient education about colon cancer by the physician and facilitating patient compliance. Aliment Pharmacol Ther 24, 1623–1630
ª 2006 Blackwell Publishing Ltd No claim to original US government works doi:10.1111/j.1365-2036.2006.03176.x
1623
1624 A . A . S I D D I Q U I et al.
INTRODUCTION Numerous studies have demonstrated that removal of adenomatous polyps is associated with a marked reduction in the incidence of colorectal cancer.1–3 Colorectal cancer is an important healthcare problem as it is the second leading cause of cancer-related mortality in the United States.4 The National Polyp Study showed a 76–90% risk reduction in the incidence of colorectal cancer in patients who had colonoscopic polypectomy, compared with reference populations.5 The decrease in the incidence of cancer was achieved with aggressive follow-up colonoscopy at 3-year intervals in patients with adenomatous polyps. The compliance rate of follow-up colonoscopy in this study was 80%. The US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society have recently issued updated joint guidelines, which recommend follow-up colonoscopy in patients with tubular adenomas every 3–5 years, according to their risk stratification.6 The efficacy of colonoscopic polypectomy in decreasing colorectal cancer incidence may be affected by poor compliance with follow-up after polypectomy. Compliance with polypectomy has been previously addressed in a private setting in a patient population with a good likelihood of compliance with their medical care.7 The present study addresses the rate of compliance following polypectomy in a veteran population, which is typically vulnerable to compliance. We also investigated factors that might be associated and/or predict poor compliance in this high-risk patient population.
METHODS
oscopy. One to two months before the follow-up procedure, the patients are sent a letter reminding them of the time and date when they are to come to the endoscopy laboratory. A week before the procedure, our scheduling nurse also calls the patients at their home telephone number as an additional reminder.
Patients We identified patients with pathology-proved adenomatous polyps excised during colonoscopy at the DVAMC from January 1998 to December 1998. Similar to the National Polyp Study,8 patients were excluded if they had a prior history of colonic disease such as cancer, Crohn’s disease or mucosal ulcerative colitis, colonic surgery, incomplete polypectomy or were deceased prior to recommended date of follow-up. In addition, all patients with invasive carcinoma limited to a polyp were excluded. Compliance with the recommendation for follow-up colonoscopy was determined from retrospective computerized patient medical record system (CPRS) review and our gastroenterology endoscopy database. Compliance with a follow-up colonoscopy was defined as the patient who appeared for their colonoscopy as scheduled in the 3- to 5-year time frame after removal of adenomatous colon polyp(s). We assessed a total of 29 clinical factors in order to determine predictors of compliance following polypectomy (Table 1). The variables selected for this study were based on previous investigations and/or our own clinical experience and information set by the Veteran Administration National Quality Improvement Data Base. This protocol was approved by the Institutional Review Board at the DVAMC.
Setting
Data collection
Our study was undertaken at the Dallas Veterans Affairs Medical Center (DVAMC) and investigated patients who had undergone an initial screening colonoscopy for colorectal cancer surveillance. At our institution, patients found to have adenomatous polyps on colonoscopy are typically contacted by a gastroenterologist to discuss their findings and/or mailed a letter that lists their findings and recommendations for a follow-up colonoscopy. Additionally, an electronic alert is sent to the patient’s primary care physician who lists the gastroenterologist’s recommendations for when the patient should follow-up for a repeat colon-
Data collected from chart review included demographics, symptoms at the time of colonoscopy, age at polypectomy, number of adenomatous polyps excised, the size of the largest polyp removed, compliance with previous healthcare visits, substance abuse, mental illness, travel distance and medication history. History of substance abuse and/or metal illness over a 12-month period prior to the study was also catalogued. We investigated all out-patient clinic visits to the DVAMC for which the patient had been scheduled over the year prior to the scheduled colonoscopy. Compliª 2006 Blackwell Publishing Ltd, Aliment Pharmacol Ther 24, 1623–1630 No claim to original US government works
Weight loss Amount of weight loss NSAID use Statin use Missed clinic appointment Psychiatric disorder Physical disability Previous colonoscopy
Smoker ETOH abuse Drug abuse First-degree relative with CA colon Second-degree relative with CA colon Rectal bleeding Change in bowel habits Abdominal pain Anorexia Diabetes HTN Anaemia Other cancers
Age Gender Race Distance travelled to hospital Living/deceased Marital status
Social history Clinical history
Statistical analysis
Past medical history
Family history
Number of polyps Size of largest polyp
ance with out-patient clinic was defined as patient appearance for all scheduled clinic visit(s) within the calendar year prior to the scheduled follow-up colonoscopy. Noncompliant patients were defined as those who missed two or more clinic appointments. We excluded emergency room visits, clinic visits scheduled while the patient was hospitalized, clinic visits listed as ‘cancelled by clinic,’ and any other outpatient visits in which it was not possible to determine from the records if the patient had actually received care. The total evaluable visits the patient had during that year were recorded. We also interrogated the number of visits patients did not maintain or cancelled. In cases in which a patient was scheduled for more than one visit on the same day, we considered the entire day as one visit. In some instances, a patient receiving two appointments at similar times was able to keep only one. These were not considered as missed appointments.
Demographics
Table 1. Factors used to assess compliance with colonoscopy
Colonoscopy findings
C O M P L I A N C E W I T H S U R V E I L L A N C E C O L O N O S C O P Y 1625
ª 2006 Blackwell Publishing Ltd, Aliment Pharmacol Ther 24, 1623–1630 No claim to original US government works
Data were analysed by SPSS statistical program (SPSS Inc., Chicago, IL, USA). Univariate analysis was performed for each variable by Student’s t-test for continuous variables and by Fischer’s exact test for dichotomous variables. The patients were grouped into whether they were compliant with a follow-up colonoscopy (n ¼ 81) or noncompliant (n ¼ 38). Variables found to be statistically significant by univariate analysis were included in a multivariate regression analysis model to determine factors that would affect compliance with surveillance colonoscopy. Variables with a P £ 0.05 (with the exception of number of first-degree relatives with colon cancer P ¼ 0.06), as determined by univariate analysis, were included in a multivariate regression analysis model. All values are presented as mean S.E.; statistical significance was determined at a P £ 0.05.
RESULTS A retrospective review of the patient medical records revealed 355 patients who had adenomatous polyps excised in 1998. There were 236 patients excluded based on the exclusion criteria for this study, while the remaining patients formed the basis of the study. Patient characteristics are outlined in Table 2. Ninetysix per cent of patients were male (mean age 64.2 1.0 years). Forty per cent (34 of 119) had
1626 A . A . S I D D I Q U I et al.
the status of follow-up colonoscopy could be determined, was 68%.
Table 2. Patient demographics No. of patients (n) Age (years) (mean S.E.M.) Male gender Prior colonoscopy Symptomatic Family history positive Polyp number, single Polyp size,
