Diverticulitis in the United States: 1998-2005: changing patterns of disease and treatment.

OBJECTIVES: Diverticular disease imposes an impressive clinical burden to the United States population, with over 300,000 admissions and 1.5 million days of inpatient care annually. Consensus regarding the treatment of diverticulitis has evolved over time, with increasing advocacy of primary anastomosis for acute diverticulitis, and nonoperative treatment of recurrent mild/moderate diverticulitis. We analyzed whether these changes are reflected in patterns of practice in a nationally-representative patient cohort.
METHODS: We used the 1998 to 2005 nationwide inpatient sample to analyze the care received by 267,000 patients admitted with acute diverticulitis, and 33,500 patients operated electively for diverticulitis. Census data were used to calculate population-based incidence rates of disease and surgical treatment. Weighted logistic regression with cluster adjustment at the hospital level was used for hypothesis testing.
RESULTS: Overall annual age-adjusted admissions for acute diverticulitis increased from 120,500 in 1998 to 151,900 in 2005 (26% increase). Rates of admission increased more rapidly within patients aged 18 to 44 years (82%) and 45 to 74 years (36%). Elective operations for diverticulitis rose from 16,100 to 22,500 per year during the same time period (29%), also with a more rapid increase (73%) in rates of surgery for individuals aged 18 to 44 years. Multivariate analysis found no evidence that primary anastomosis is becoming more commonly used.
CONCLUSIONS: We are the first to report dramatic changes in rates of treatment for diverticulitis in the United States. The causes of this emerging disease pattern are unknown, but certainly deserve further investigation. For patients undergoing surgery for acute diverticulitis, there was little change over time in the likelihood of a primary anastomosis.