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Radiology May 2012To estimate the prevalence of underlying adenocarcinoma of the colon in patients in whom acute diverticulitis was diagnosed at computed tomography (CT) and to compare... (Review)
Review
PURPOSE
To estimate the prevalence of underlying adenocarcinoma of the colon in patients in whom acute diverticulitis was diagnosed at computed tomography (CT) and to compare that to the prevalence of colon cancer in the general population.
MATERIALS AND METHODS
A comprehensive literature review was performed to find articles in which patients with CT diagnosis of acute diverticulitis underwent surgery, colonoscopy, or barium enema study within 24 weeks. Patients meeting these criteria were included for analysis. A pooled prevalence of cancer was calculated on the basis of a random effects model and compared qualitatively with the prevalence of cancer in the general population. The 95% confidence intervals around the prevalence of cancer in the study populations were determined.
RESULTS
Ten articles met the inclusion criteria. Data from these articles included only 771 patients who underwent surgery, colonoscopy, or barium enema study within 24 weeks of diagnosis. Fourteen patients were found to have colon cancer, for a prevalence of 2.1% (95% confidence interval: 1.2%, 3.2%). This compares to a calculated estimated prevalence of 0.68% among U.S. adults older than 55 years.
CONCLUSION
There are limited data to support the recommendation to perform colonoscopy after a diagnosis of acute diverticulitis.
Topics: Adenocarcinoma; Barium Sulfate; Colonic Neoplasms; Colonoscopy; Confidence Intervals; Contrast Media; Diagnosis, Differential; Diverticulitis, Colonic; Humans; Predictive Value of Tests; Prevalence; Tomography, X-Ray Computed
PubMed: 22517956
DOI: 10.1148/radiol.12111869 -
British Journal of Cancer Jan 2010Rectal bleeding is a recognised early symptom of colorectal cancer. This study aimed to assess the diagnostic accuracy of symptoms, signs and diagnostic tests in... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Rectal bleeding is a recognised early symptom of colorectal cancer. This study aimed to assess the diagnostic accuracy of symptoms, signs and diagnostic tests in patients with rectal bleeding in relation to risk of colorectal cancer in primary care.
METHODS
Diagnostic accuracy systematic review. Medline (1966 to May 2009), Embase (1988 to May 2009), British Nursing Index (1991 to May 2009) and PsychINFO (1970 to May 2009) were searched. We included cohort studies that assessed the diagnostic utility of rectal bleeding in combination with other symptoms, signs and diagnostic tests in primary care. An eight-point quality assessment tool was produced to assess the quality of included studies. Pooled positive likelihood ratios (PLRs), sensitivities and specificities were calculated.
RESULTS
Eight studies incorporating 2323 patients were included. Average weighted prior probability of colorectal cancer was 7.0% (range: 3.3-15.4%, median: 8.1%). Age > or = 60 years (pooled PLR: 2.79, 95% confidence interval (CI) 2.00-3.90), weight loss (pooled PLR: 1.89, 95% CI: 1.03-3.07) and change in bowel habit (pooled PLR: 1.92, 95% CI: 0.54-3.57) raise the probability of colorectal cancer into the range of referral to secondary care but do not conclusively 'rule in' the diagnosis. Presence of severe anaemia has the highest diagnostic value (pooled PLR: 3.67, 95% CI: 1.30-10.35), specificity 0.95 (95% CI: 0.93-0.96), but still only generates a post-test probability of 21.6%.
CONCLUSIONS
In patients with rectal bleeding who present to their general practitioner, additional 'red flag' symptoms have modest diagnostic value. These findings have implications in relation to recommendations contained in clinical practice guidelines.
Topics: Adenocarcinoma; Adult; Aged; Anemia; Barium Sulfate; Cohort Studies; Colonoscopy; Colorectal Neoplasms; Enema; Family Practice; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Pain; Primary Health Care; Prospective Studies; Radiography; Rectum; Reference Standards; Risk; Sensitivity and Specificity; Sigmoidoscopy; Ultrasonography; Weight Loss
PubMed: 19935790
DOI: 10.1038/sj.bjc.6605426 -
Journal of General Internal Medicine Jan 2005Though primary care patients commonly present with rectal bleeding, the optimal evaluation strategy remains unknown. (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND
Though primary care patients commonly present with rectal bleeding, the optimal evaluation strategy remains unknown.
OBJECTIVE
To compare the cost-effectiveness of four diagnostic strategies in the evaluation of rectal bleeding.
DESIGN
Cost-effectiveness analysis using a Markov decision model.
DATA SOURCES
Systematic review of the literature, Medicare reimbursement data, Surveillance, Epidemiology, and End Results (SEER) Cancer Registry.
TARGET POPULATION
Patients over age 40 with otherwise asymptomatic rectal bleeding.
TIME HORIZON
The patient's lifetime.
PERSPECTIVE
Modified societal perspective.
INTERVENTIONS
Watchful waiting, flexible sigmoidoscopy, flexible sigmoidoscopy followed by air contrast barium enema (FS+ACBE), and colonoscopy.
OUTCOME MEASURES
Incremental cost-effectiveness ratio.
RESULTS OF BASE-CASE ANALYSIS
The incremental cost-effectiveness ratio for colonoscopy compared with flexible sigmoidoscopy was 5,480 dollars per quality-adjusted year of life saved (QALY). Watchful waiting and FS+ACBE were more expensive and less effective than colonoscopy.
RESULTS OF SENSITIVITY ANALYSES
The cost of colonoscopy was reduced to 1,686 dollars per QALY when age at entry was changed to 45. Watchful waiting became the least expensive strategy when community procedure charges replaced Medicare costs, when age at entry was maximized to 80, or when the prevalence of polyps was lowered to 7%, but the remaining strategies provided greater life expectancy at relatively low cost. The strategy of FS+ACBE remained more expensive and less effective in all analyses. In the remaining sensitivity analyses, the incremental cost-effectiveness of colonoscopy compared with flexible sigmoidoscopy never rose above 34,000 dollars.
CONCLUSIONS
Colonoscopy is a cost-effective method to evaluate otherwise asymptomatic rectal bleeding, with a low cost per QALY compared to other strategies.
Topics: Adult; Barium Sulfate; Colonic Polyps; Colonoscopy; Cost-Benefit Analysis; Enema; Gastrointestinal Hemorrhage; Humans; Markov Chains; Mass Screening; Quality-Adjusted Life Years; Rectum; Sigmoidoscopy
PubMed: 15693933
DOI: 10.1111/j.1525-1497.2005.40077.x