Single Colonoscopy Research Articles

Cost-effectiveness of a single colonoscopy in screening for colorectal cancer.

A single colonoscopy at the age of 65 years has been recommended as a potential option to screen for colorectal cancer. This study compares the cost-effectiveness of 2 screening programs based on a single or repeated colonoscopy. The cost-effectiveness of screening is analyzed with a computer model of a Markov process. A hypothetical population of 100 000 subjects aged 50 years undergoes a single colonoscopy at the age of 65 years or repeated colonoscopy every 10 years starting at the age of 50. Transition rates are estimated from US vital statistics and cancer statistics and published data on polyp incidence, patient compliance, and efficacy of colonoscopy plus polypectomy in cancer prevention. Costs of screening and cancer care are estimated from the 1998 Medicare reimbursement data using the perspective of a third-party payer. Compared with no screening, the incremental cost-effectiveness ratio of a single or repeated colonoscopy amounts to $2981 or to $10 983 per life year saved, respectively. A single colonoscopy saves most life years if done at the age of 60, but becomes most cost-effective after the age of 70. Depending on the level of compliance, repeated colonoscopies save 2 to 3 times more lives than a screening program based on a single colonoscopy. A repeated colonoscopy every 10 years offers better prevention against colorectal cancer and represents a medically more desirable screening option. If high costs or low patient compliance renders this option not feasible, a single colonoscopy at the age of 65 would represent a highly cost-effective alternative.

Cost-effectiveness of screening for colorectal cancer in the general population.

A recent expert panel recommended that persons at average risk of colorectal cancer (CRC) begin screening for CRC at age 50 years using 1 of several strategies. However, many aspects of different CRC screening strategies remain uncertain. To assess the consequences, costs, and cost-effectiveness of CRC screening in average-risk individuals. Cost-effectiveness analysis from a societal perspective using a Markov model. Hypothetical subjects representative of the 50-year-old US population at average risk for CRC. Simulated clinical practice in the United States. Discounted lifetime costs, life expectancy, and incremental cost-effectiveness (CE) ratio, compared used 22 different CRC screening strategies, including those recommended by the expert panel. In 1 base-case analysis, compliance was assumed to be 60% with the initial screen and 80% with follow-up or surveillance colonoscopy. The most effective strategy for white men was annual rehydrated fecal occult blood testing (FOBT) plus sigmoidoscopy (followed by colonoscopy if either a low- or high-risk polyp was found) every 5 years from age 50 to 85 years, which resulted in a 60% reduction in cancer incidence and an 80% reduction in CRC mortality compared with no screening, and an incremental CE ratio of $92,900 per year of life gained compared with annual unrehydrated FOBT plus sigmoidoscopy every 5 years. In a base-case analysis in which compliance with screening and follow-up is assumed to be 100%, screening more often than every 10 years was prohibitively expensive; annual rehydrated FOBT plus sigmoidoscopy every 5 years had an incremental CE ratio of $489,900 per life-year gained compared with the same strategy every 10 years. Other strategies recommended by the expert panel were either less effective or cost more per year of life gained than the alternatives. Colonoscopy every 10 years was less effective than the combination of annual FOBT plus sigmoidoscopy every 5 years. However, a single colonoscopy at age 55 years achieves nearly half of the reduction in CRC mortality obtainable with colonoscopy every 10 years. Because of increased life expectancy among white women and increased cancer mortality among blacks, CRC screening was even more cost-effective in these groups than in white men. Screening for CRC, even in the setting of imperfect compliance, significantly reduces CRC mortality at costs comparable to other cancer screening procedures. However, compliance rates significantly affect the incremental CE ratios. In this model of CRC, 60% compliance with an every 5-year schedule of screening was roughly equivalent to 100% compliance with an every 10-year schedule. Mathematical modeling used to inform clinical guidelines needs to take into account expected compliance rates. JAMA. 2000;284:1954-1961.

Ogilvie's syndrome: colonoscopic decompression and analysis of predisposing factors.

Forty-eight cases of Ogilvie's syndrome, colonic pseudo-obstruction, presenting between 1983 and 1989 were retrospectively reviewed to assess the results of colonoscopic decompression and to identify potential etiologic factors. Three patients had spontaneous resolution with medical treatment. Forty-five patients required 60 colonoscopic decompressions: 38 (84 percent) were successfully treated using colonoscopy; five (11 percent) required an operation; and two died within 48 hours of colonoscopy from medical causes. No complications or deaths were the result of colonoscopy. Twenty-nine patients (64 percent) were successfully treated with a single colonoscopy. One-third of patients required serial decompressions. Average cecal diameter in patients with successful colonoscopic decompression was 12.4 cm but was larger for patients requiring more than one colonoscopy (13.3 cm) and for those who failed colonoscopic therapy (13.4 cm). The spine or retroperitoneum had been traumatized or manipulated in 52 percent of patients. Patients with Ogilvie's syndrome were being treated with narcotics (56 percent), H-2 blockers (52 percent), phenothiazines (42 percent), calcium-channel blockers (27 percent), steroids (23 percent), tricyclic antidepressants (15 percent), and epidural analgesics (6 percent) at diagnosis. Electrolyte abnormalities included hypocalcemia (63 percent), hyponatremia (38 percent), hypokalemia (29 percent), hypomagnesemia (21 percent), and hypophosphatemia (19 percent). Colonoscopic decompression in Ogilvie's syndrome is safe and effective management. Multiple pharmacologic and metabolic factors, as well as spinal and retroperitoneal trauma, appear to alter autonomic regulation of colonic function, resulting in colonic pseudo-obstruction.