Low Rates of Gastrointestinal and Non-Gastrointestinal Complications for Screening or Surveillance Colonoscopies in a Population-Based Study.

BACKGROUND: The full spectrum of serious non-gastrointestinal post-colonoscopy complications has not been well characterized. We analyzed rates of and factors associated with adverse post-colonoscopy gastrointestinal (GI) and non-gastrointestinal events (cardiovascular, pulmonary, or infectious) attributable to screening or surveillance colonoscopy (S-colo) and non-screening or non-surveillance colonoscopy (NS-colo).

METHODS: We performed a population-based study of colonoscopy complications using databases from California hospital-owned and nonhospital-owned ambulatory facilities, emergency departments, and hospitals from January 1, 2005 through December 31, 2011. We identified patients who underwent S-colo (1.58 million), NS-colo (1.22 million), or low-risk comparator procedures (joint injection, aspiration, lithotripsy; arthroscopy, carpal tunnel; or cataract; 2.02 million) in California's Ambulatory Services Databases. We identified patients who developed adverse events within 30 days, and factors associated with these events, through patient-level linkage to California's Emergency Department and Inpatient Databases.

RESULTS: After S-colo, the numbers of lower GI bleeding, perforation, myocardial infarction, and ischemic stroke per 10,000-persons were 5.3 (95% confidence interval [CI], 4.8-5.9), 2.9 (95% CI, 2.5-3.3), 2.5 (95% CI, 2.1-2.9), and 4.7 (95% CI, 4.1-5.2) without biopsy or intervention; with biopsy or intervention, numbers per 10,000-persons were 36.4 (95% CI, 35.1-37.6), 6.3 (95% CI, 5.8-6.8), 4.2 (95% CI, 3.8-4.7), and 9.1 (95% CI, 8.5-9.7). Rates of dysrhythmia were higher. After NS-colo, event rates were substantially higher. Most serious complications led to hospitalization, and most GI complications occurred within 14 days of colonoscopy. Ranges of adjusted odds ratios for serious GI complications, myocardial infarction, ischemic stroke, and serious pulmonary events after S-colo vs comparator procedures were 2.18 (95% CI, 2.02-2.36) to 5.13 (95% CI, 4.81-5.47), 0.67 (95% CI, 0.56-0.81) to 0.99 (95% CI, 0.83-1.19), 0.66 (95% CI, 0.59-0.75) to 1.13 (95% CI, 0.99-1.29), and 0.64 (95% CI, 0.61-0.68) to 1.05 (95% CI, 0.98-1.11). Biopsy or intervention, comorbidity, black race, low income, public insurance, and NS-colo were associated with post-colonoscopy adverse events.

CONCLUSIONS: In a population-based study in California, we found that following S-colo, rates of serious GI adverse events were low but clinically relevant, and that rates of myocardial infarction, stroke, and serious pulmonary events were no higher than after low-risk comparator procedures. Rates of myocardial infarction are similar to, but rates of stroke are higher than, those reported for the general population.