Computed tomographic colonography compared with colonoscopy or barium enema for diagnosis of colorectal cancer in older symptomatic patients: two multicentre randomised trials with economic evaluation (the SIGGAR trials).

BACKGROUND: Computed tomographic colonography (CTC) is a relatively new diagnostic test that may be superior to existing alternatives to investigate the large bowel. OBJECTIVES: To compare the diagnostic efficacy, acceptability, safety and cost-effectiveness of CTC with barium enema (BE) or colonoscopy. DESIGN: Parallel randomised trials: BE compared with CTC and colonoscopy compared with CTC (randomisation 2 : 1, respectively). SETTING: A total of 21 NHS hospitals. PARTICIPANTS: Patients aged ≥ 55 years with symptoms suggestive of colorectal cancer (CRC). INTERVENTIONS: CTC, BE and colonoscopy. MAIN OUTCOME MEASURES: For the trial of CTC compared with BE, the primary outcome was the detection rate of CRC and large polyps (≥ 10 mm), with the proportion of patients referred for additional colonic investigation as a secondary outcome. For the trial of CTC compared with colonoscopy, the primary outcome was the proportion of patients referred for additional colonic investigation, with the detection rate of CRC and large polyps as a secondary outcome. Secondary outcomes for both trials were miss rates for cancer (via registry data), all-cause mortality, serious adverse events, patient acceptability, extracolonic pathology and cost-effectiveness. RESULTS: A total of 8484 patients were registered and 5384 were randomised and analysed (BE trial: 2527 BE, 1277 CTC; colonoscopy trial: 1047 colonoscopy, 533 CTC). Detection rates in the BE trial were 7.3% (93/1277) for CTC, compared with 5.6% (141/2527) for BE (p = 0.0390). The difference was due to better detection of large polyps by CTC (3.6% vs. 2.2%; p = 0.0098), with no significant difference for cancer (3.7% vs. 3.4%; p = 0.66). Significantly more patients having CTC underwent additional investigation (23.5% vs. 18.3%; p = 0.0003). At the 3-year follow-up, the miss rate for CRC was 6.7% for CTC (three missed cancers) and 14.1% for BE (12 missed cancers). Significantly more patients randomised to CTC than to colonoscopy underwent additional investigation (30% vs. 8.2%; p < 0.0001). There was no significant difference in detection rates for cancer or large polyps (10.7% for CTC vs. 11.4% for colonoscopy; p = 0.69), with no difference when cancers (p = 0.94) and large polyps (p = 0.53) were analysed separately. At the 3-year follow-up, the miss rate for cancer was nil for colonoscopy and 3.4% for CTC (one missed cancer). Adverse events were uncommon for all procedures. In 1042 of 1748 (59.6%) CTC examinations, at least one extracolonic finding was reported, and this proportion increased with age (p < 0.0001). A total of 149 patients (8.5%) were subsequently investigated, and extracolonic neoplasia was diagnosed in 79 patients (4.5%) and malignancy in 29 (1.7%). In the short term, CTC was significantly more acceptable to patients than BE or colonoscopy. Total costs for CTC and colonoscopy were finely balanced, but CTC was associated with higher health-care costs than BE. The cost per large polyp or cancer detected was £4235 (95% confidence interval £395 to £9656). CONCLUSIONS: CTC is superior to BE for detection of cancers and large polyps in symptomatic patients. CTC and colonoscopy detect a similar proportion of large polyps and cancers and their costs are also similar. CTC precipitates significantly more additional investigations than either BE or colonoscopy, and evidence-based referral criteria are needed. Further work is recommended to clarify the extent to which patients initially referred for colonoscopy or BE undergo subsequent abdominopelvic imaging, for example by computed tomography, which will have a significant impact on health economic estimates. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95152621.

Intussusception in children: cost-effectiveness of ultrasound vs diagnostic contrast enema.

PURPOSE: The aim of the study was to compare the cost-effectiveness of different imaging strategies for the diagnosis of pediatric intussusception using a decision analytic model. METHODS: A Markov decision model was constructed to model effects of radiation exposure at the time of intussusception in a hypothetical cohort of 2-year-old children. The 2 strategies compared were ultrasound followed conditionally by contrast enema (US/CE) vs contrast enema (CE) alone. The model simulated short-term and long-term outcomes of the patients, calculating the average quality-adjusted life years (QALYs) and health care costs associated with each arm. RESULTS: The use of ultrasound as a first-line diagnostic modality would result in a decrease of 79.3 and 59.7 cases of radiation-induced malignancy per 100,000 male and female children evaluated, respectively. For male and female children with intussusception, US/CE was both the most costly initial imaging strategy and the most effective compared with CE. The incremental cost-effectiveness ratios of US/CE to CE was $70,100 (boy) and $92,227 (girl) per quality-adjusted life years gained. CONCLUSIONS: In a Markov decision model of pediatric acute intussusception, initial US/CE was both the most costly and the most effective strategy.

Value-of-information analysis to guide future research in colorectal cancer screening.

PURPOSE: To identify the most useful areas for research in colorectal cancer (CRC) screening by using a value-of-information analysis. MATERIALS AND METHODS: Cost-effectiveness of screening strategies, including colonoscopy, computed tomographic (CT) colonography, flexible sigmoidoscopy, and barium enema examination, were compared by using a Markov model. Monetary net benefit (NB), a measure of cost-effectiveness, was calculated by multiplying effect (life-years gained) by willingness to pay (100,000 dollars per life-year gained) and subtracting cost. A value-of-information analysis was used to estimate the expected benefit of future research that would eliminate the decision uncertainty. RESULTS: In the reference-case analysis, colonoscopy was the optimal test with the highest NB (1945 dollars per subject invited for screening compared with 1862 dollars, 1717 dollars, and 1653 dollars for CT colonography, flexible sigmoidoscopy, and barium enema examination, respectively). Results of probabilistic sensitivity analysis indicated that colonoscopy was the optimal choice in only 45% of the simulated scenarios, whereas CT colonography, flexible sigmoidoscopy, and barium enema examination were the optimal strategies in 23%, 16%, and 15% of the scenarios, respectively. Only two parameters were responsible for most of this uncertainty about the optimal test for CRC screening: the increase in adherence with less invasive tests and CRC natural history. The expected societal monetary benefit of further research in these areas was estimated to be more than 15 billion dollars. CONCLUSION: Results of value-of-information analysis show that future research on the optimal test for CRC screening has a large societal impact. Priority should be given to research on the increase in adherence with screening by using less invasive tests and to better understanding of the natural history of CRC.

Cost-effectiveness and patient tolerance of low-attenuation oral contrast material: milk versus VoLumen.

OBJECTIVE: The purpose of our study was to prospectively compare the cost, effectiveness, and patient tolerance of milk and VoLumen, a 0.1% barium suspension, in patients undergoing abdominal and pelvic CT with oral and i.v. contrast media. SUBJECTS AND METHODS: Two hundred fifteen consecutive outpatients were randomly assigned to receive either whole milk (n = 115) or VoLumen (n = 100). Results were independently reviewed by two radiologists who were blinded to the oral contrast agent used. Degree of bowel distention was qualitatively scored on a 4-point scale, and bowel wall visibility was graded qualitatively on a yes-or-no basis. A questionnaire regarding oral contrast tolerability was provided to each patient. Cost comparison of the two agents was performed. RESULTS: No statistically significant differences were seen between whole milk and VoLumen with respect to degree of bowel distention and mural visualization for all segments of bowel studied (p > 0.05 for both reviewers). Significantly more patients ranked milk as pleasant in taste compared with VoLumen (p < 0.0001). More patients preferred milk compared with VoLumen (p < 0.0001). Milk was better tolerated than VoLumen, with fewer abdominal side effects, including abdominal discomfort (p = 0.019), cramping (p = 0.019), nausea (p = 0.016), and diarrhea (p = 0.0002). The cost per patient for VoLumen is $18 compared with $1.48 for milk. CONCLUSION: Whole milk is comparable to VoLumen with respect to bowel distention and bowel wall visualization and has a lower cost, better patient acceptance, and fewer adverse symptoms. Milk is a cost-effective alternative to VoLumen as a low-attenuation oral contrast agent.

Gastrointestinal tract labeling for MDCT of abdomen: comparison of low density barium and low density barium in combination with water.

The purpose of the study was to compare the quality of stomach and small bowel marking/labeling using 1,350 ml of low-density barium alone (VoLumen) with 900 ml of low-density barium and 450 ml of water for 16-MDCT scans of the abdomen and pelvis and assess cost benefits with the two protocols. In this IRB approved study, 80 consecutive patients scheduled for routine CECT (contrast-enhanced CT) of the abdomen-pelvis were studied. Patients were randomized into two groups and were administered either 1,350 ml of VoLumen (two bottles at 20-min intervals, one half bottle at 50 min and the last half on the table) or 900 ml of VoLumen (two bottles at 20-min intervals and 450 ml water on the table). Portal venous phase scanning (detector collimation=0.625 mm, speed=18.75 mm, thickness=5 mm) was subsequently performed. Images were reconstructed in axial and coronal plane at the CT console. Two blinded readers used a pre-designed template to assess distension and wall characteristics of the stomach and small bowel on a 5-point scale. Median scores with the two protocols were compared using the Wilcoxon rank sum test. The stomach and small bowel labeling was rated fair to optimal in all patients and did not differ significantly in the two protocols. The mean scores for distension of the small bowel and stomach were comparable. Inter-observer agreement for bowel labeling was found to be excellent (k 0.81). With the use of coronal images there was increased reader confidence in tracing the small bowel with both protocols. Acceptance for two bottles of VoLumen and water was greater among patients as compared to three bottles of VoLumen. Use of two bottles of VoLumen and water combination cost less than three bottles of VoLumen. Stomach and small bowel labeling with administration of 900 ml of VoLumen followed by 450 ml of water is cost effective and compares well to 1,350 ml of VoLumen alone.

Outcomes of mass screening for gastric carcinoma.

BACKGROUND: Therapeutic results of gastric cancer have been improved by early detection of gastric cancer with the mass screening system in Japan. The objective of our study was to assess the efficacy of mass screening for gastric cancer by using a barium meal. METHODS: A series of 1050 patients (364 in the screened group and 686 in the nonscreened group) were included in this study from April 1992 to March 2000. Patient characteristics, therapeutic results, and prognostic factors were compared in the two groups. RESULTS: The screened patients tended to be younger and male, with tumors in the middle third of the stomach that were of a macroscopically superficial type, with a smaller diameter, and at an earlier stage. They had fewer metastatic lymph nodes and underwent more frequent curative resection. Among the screened patients with curatively resected disease, tumors tended to be of a smaller diameter, and there were fewer metastatic lymph nodes in both early and advanced cases. Disease-specific survival was significantly better in the screened cases among all registered and curatively resected patients. Mass screening achieved significantly better surgical results in early or advanced gastric cancer patients who received curative resection. Multivariate analysis revealed that mass screening was an independent prognostic factor (hazard ratio, .3949; P < .0001), together with depth of invasion, lymph node metastasis, age, and tumor diameter. CONCLUSIONS: Mass screening by using barium meal examination for gastric cancer detects cancer at an early stage and produces good therapeutic results.

Barium swallow.

After completing this article, the reader should be able to: Describe the functional phases and anatomy of swallowing. Detail common underlying causes of dysphagia and their radiographic signs and clinical correlates. List the risk factors for gastroesophageal reflux disease. Differentiate the procedures and goals of barium swallow from those of modified barium swallow. Predict future trends in demand for barium contrast imaging exams related to swallowing dysfunction.

Immediate radiographic assessment following laparoscopic antireflux operations is unnecessary.

BACKGROUND: Laparoscopic antireflux operations (LAP) have become increasingly common for the treatment of gastroesophageal reflux disease (GERD). We sought to determine if routine postoperative barium contrast studies following LAP were clinically efficacious in identifying technical problems and life-threatening complications related to the surgical intervention. METHODS: From January 1996 to December 1997, 112 barium studies were performed following 112 LAP procedures (47 male/65 female patients; mean age, 51 years) (group I). This group was compared to a subsequent cohort of 67 patients who underwent LAP between January 1998 and July 1998 without routine early postoperative barium contrast study (group II). RESULTS: In 111/112 of the barium studies of group I, no radiographic abnormality was identified. The average length of stay (LOS) for these patients was 2.6 days. Routine barium studies were not utilized in group II. The average length of stay for patients in group II was 1.4 days. Twelve group II patients underwent early postoperative barium studies to evaluate suspicious clinical symptoms. None of these 12 postoperative studies identified important problems, nor did they alter the patients' clinical management. However, because of the barium study, their LOS was equivalent to those patients who had undergone routine barium study (2.4 days). There was an increase of $1451.80 in hospital charges in the group of patients who had a barium study, largely as a result of the increased LOS. CONCLUSION: The routine use of these studies results in increased patient charges and a prolongation in the length of hospital stay. Immediate postoperative barium studies following laparoscopic antireflux operations are of little value in determining important postoperative problems among patients undergoing LAO.

Cost-effectiveness of colorectal cancer screening.

PURPOSE: To determine the most cost-effective colorectal cancer screening strategy costing less than $100,000 per life-year saved and to determine how available strategies compare with each other. MATERIALS AND METHODS: Standardized methods were used to calculate incremental cost-effectiveness ratios (ICERs) from published estimates of cost and effectiveness of colorectal cancer screening strategies, and the direction and magnitude of any effect on the ratio from parameter estimate adjustments based on literature values were estimated. RESULTS: Strategies in which double-contrast barium enema examination was performed emerged as optimal from all studies included. In average-risk individuals, screening with double-contrast barium enema examination every 3 years, or every 5 years with annual fecal occult blood testing, had an ICER of less than $55,600 per life-year saved. However, double-contrast barium enema examination screening every 3 years plus annual fecal occult blood testing had an ICER of more than $100,000 per life-year saved. Colonoscopic screening had an ICER of more than $100,000 per life-year saved, was dominated by other screening strategies, and offered less benefit than did double-contrast barium enema examination screening. CONCLUSION: Double-contrast barium enema examination can be a cost-effective component of colorectal cancer screening, but further modeling efforts are necessary.

The role of barium enema in colostomy closure in trauma patients.

Recently, the routine use of barium enema preceding colostomy closure in trauma patients has been challenged. It has been argued that the nature of the injury should be apparent from the initial laparotomy and that the likelihood of finding an unsuspected colonic lesion in the young, previously healthy patients who constitute the majority of trauma patients is very small. We retrospectively reviewed 124 consecutive cases of patients who received colostomy takedowns for trauma. One hundred six of the patients had preoperative barium enema evaluation. 87.1 per cent of the examinations were negative, with a subsequent stoma closure complication rate of 20.4 per cent. Of the 13 positive barium enemas, 9 were falsely positive. These patients had a higher stoma closure complication rate of 39 per cent, a fact that could not be explained on the basis of their abnormal studies. The 18 patients who did not have barium enema performed did not have an increase in complications (17.6%). Barium enema failed to uncover unsuspected pertinent diagnoses, often added unnecessary delays and expense, and in no case changed the operative management. Contrast studies were found to be useful in defining anatomy in cases of known fistulas and when the takedowns were performed without the benefit of operative reports from the previous surgery.

The cost benefit of changing protocols in the management of intussusception.

BACKGROUND: At a time when pressure is being applied to healthcare systems to reduce costs and improve efficiency, both the medical and financial implications of changing practices need to be documented. METHODS: A review was undertaken of 703 patients with intussusception, treated during a 10-year period from 1983. RESULTS: This review showed that changes to the protocol for the management of intussusception have not only benefited the patient by reducing the morbidity and the operative rate, but also have led to a reduction in the length of hospital stay, providing significant cost savings to the health system. The reduction in the operative rate accounts for an estimated annual saving at the Royal Children's Hospital of $139,000. CONCLUSIONS: Improvements in the management of intussusception have resulted in significant reductions in the costs of treatments. The recent diagnosis-related group casemix funding arrangements mean, however, that the Royal Children's Hospital benefits more financially from inappropriate operative management of intussusception, than from non-operative management. Funding arrangements should not discourage optimal treatment.

Oral administration of a low-cost negative contrast agent: a three-year experience in routine practice.

A low cost, well tolerated, and effective gastrointestinal contrast agent is needed for abdominal MRI. The authors tested, in vitro and in routine practice, a mixture of 192 g of barium sulfate (Micropaque HD oral, Guerbet, France) diluted in 500 ml of gastric antacid (Maalox, Rohrer, Fort Washington, PA). Its T1 and T2 relaxation times were 324 and 14 msec, respectively (.2 T). This contrast agent was used in routine practice in 789 patients (.5 T). It had a low signal intensity in 86% and 82% of the cases on T1- and T2-weighted sequences, respectively. No side effect due to magnetic susceptibility was seen, even with gradient-echo sequences. The dilution of barium sulfate in gastric antacid, instead of water, causes a low signal intensity on all sequences for a low barium sulfate concentration (38% w/v). This product is an effective and low cost contrast agent in routine practice.

Colonoscopy evaluations: justification by cost?

The type of colonic imaging (radiological vs colonoscopic) for evaluating symptomatic patients without evidence of bleeding in both an efficacious and cost-conserving manner has become a very debated issue. In a randomized, controlled clinical trial, the authors hoped to examine the prevalence of neoplasm and the effectiveness and cost-effectiveness of initial diagnostic strategies of colonoscopy versus flexible sigmoidoscopy and air contrast barium enema in patients without evidence of intestinal bleeding. One hundred forty-nine patients over the age of 40 with symptoms suggestive a colonic disease without evidence of bleeding (no hematechezia, negative test for fecal occult blood, and normal serum hemoglobin) were randomized to undergo either initial colonoscopy or flexible sigmoidoscopy plus barium enema. Patients with incomplete lower GI tests were referred for the corresponding alternative imaging modality. Cost analyses using sensitivity analysis were performed. Baseline information with respect to age, race, sex, inpatient status, reason for referral, mean weight loss, hemoglobin, blood urea nitrogen, and albumin were similar in both groups. Eighteen patients (24%) who initially received air contrast barium enema and flexible sigmoidoscopy then required colonoscopy, whereas only five patients (6%) who initially underwent colonoscopy first required air contrast barium enema plus flexible sigmoidoscopy. The study found that: a) The prevalence of cancer in the study was low (one of 149 patients); b) initial colonoscopy detected more persons with adenomas than that of air contrast barium enema plus flexible sigmoidoscopy (23 of 75 patients vs 13 of 74 patients, odds radio, 2.07, CI,0.90-4.92; this approached significance); and c) air contrast barium enema plus flexible sigmoidoscopy detected more diverticulosis (46 of 74 patients vs 31 of 75 patients, odds ratio, 0.41, 95% CI, 0.21-0.87). The significant conclusions were that patients undergoing flexible sigmoidoscopy plus air contrast barium enema were more likely to undergo alternative procedures and that sensitivity analysis suggested that, for most areas in the United States, initial colonoscopy would be more cost-effective for the outcome of detection of adenomas (1).

Evaluation of "Gastromiro" for bowel opacification during computed tomography: comparison with diatrizoate and barium sulphate.

A new oral formulation of iopamidol, "Gastromiro", was evaluated as a bowel contrast agent during abdominal computed tomography (CT). Comparison was made with the well established agents sodium/meglumine diatrizoate ("Urografin 370") and dilute barium sulphate ("E-Z CAT") in a randomized, blind study of 150 consecutive patients undergoing abdominal and/or pelvic CT. Parameters assessed included quality of bowel opacification, artefact generation, contrast-medium palatibility, side effects and cost. No significant difference was found between the three contrast media in stomach- or small-bowel opacification. E-Z CAT was superior at opacifying the caecum/ascending colon. No compelling reason to choose a particular agent was found in the other assessed parameters, but cost is a significant factor.

Long-term costs after gastroenterology consultation with endoscopy versus radiography in dyspepsia.

A randomized clinical trial assessed the medical costs during 6 months after the evaluation of dyspepsia by gastroenterology consultation with esophagogastroduodenoscopy versus barium radiography. Primary care physicians entered patients whose dyspepsia responded incompletely to empiric therapy or recurred. The consultation/endoscopy group (N = 32) was similar (p greater than 0.23) to the radiography group (N = 34) regarding age, gender, physician visits, and costs of all dyspepsia drugs and H2 blockers during 6 months before evaluation. Most patients had non-ulcer dyspepsia. Costs during the succeeding 6 months (consultation/endoscopy versus radiography groups) were physician visits ($33.1 +/- 14.5 vs. $114.2 +/- 23.3, p less than 0.005); radiologic procedures ($70.5 +/- 37.3 vs. $67.6 +/- 22.5, p greater than 0.30); all dyspepsia drugs ($30.4 +/- 10.0 vs. $100.1 +/- 36.8, p = 0.08); H2 blockers ($25.4 +/- 9.5 vs. $96.0 +/- 34.7, p = 0.06); and total cost ($134.0 +/- 43.8 vs. $435.3 +/- 93.9, p = 0.006). The higher total cost in the radiography group was partly due to the referral of 7 patients (21%) for gastroenterology consultation due to persistent dyspepsia, 6 of whom had endoscopy versus the performance of radiography in 0 of the 32 consultation/endoscopy patients (p less than 0.025). Dyspepsia self-ratings were similar.

Is colonoscopic screening appropriate in asymptomatic patients with family history of colon cancer?

Colonoscopy has been advocated by some investigators as the most appropriate means of screening asymptomatic patients with a positive family history of colorectal cancer. However, results of such screening have been widely disparate. The purpose of this study was to evaluate the yield of colonoscopy in a cohort of completely asymptomatic individuals with one or two first-degree relatives with a history of colorectal cancer and to compare this yield with that of colonoscopy in a group of patients with apparent anal bleeding. Patients with possible genetic disorders, such as familial polyposis, were excluded. A total of 160 asymptomatic patients and a comparison group of 137 patients with nonacute anorectal bleeding underwent colonoscopy. Colonoscopy was completed in 143 of the 160 study patients (89 percent) and in all of the comparison patients and did not result in any complications. Twenty-two adenomas were found in 17 study patients (10.6 percent); 16 of the 22 adenomas were less than 1 cm in size. In the comparison group, eight adenomas were identified (5.8 percent of patients). No cancers were identified. The difference in polyp frequency between groups was not significant. The relatively low yield of colorectal neoplasms discovered at colonoscopy in this study may in part be due to the small sample size or to the strict criteria used to define these asymptomatic patients but does not lend strong support to the notion that colonoscopy is an appropriate first step in screening the asymptomatic patient with one or two first-degree relatives with colon cancer.