Acute Appendicitis Risks of Complications: Age and Medicaid Insurance

Objectives: To describe the epidemiology of acute appendicitis in children from Washington State, and to determine important risk factors for complications.

Design: Retrospective cohort study.

Setting: All children (<17 years old) treated in Washington State who were identified by hospital discharge diagnosis codes from 1987 through 1996.

Methods: The hospital discharge data were reviewed for all children with a primary diagnosis code for acute appendicitis. Complicated disease was defined as perforation or abscess formation.

Results: Young children (0-4 years old) had the lowest annual incidence of acute appendicitis, but they had a 5-fold increased risk of complicated disease (odds ratio: 4.9; 95% confidence interval: 4.0-5.9), compared with teenagers. Children with Medicaid insurance had a 1.3-fold increased risk of complicated disease, compared with children with commercial insurance (odds ratio: 1.3: 95% confidence interval: 1.2-1.4). Children with Medicaid insurance had significantly longer average length of stay (4.0+/-3.7 days) than all other payers (commercial insurance: 3.3+/-4.0 days; health maintenance organization: 3.5+/-3.1 days; and self-insured: 3.7+/-5.8 days).

Conclusions: Very young children had the greatest risk of complicated disease. Children with Medicaid insurance had increased risk of complicated disease, compared with children with commercial health insurance and longer length of stay. Additional studies are needed to evaluate barriers to care for children with Medicaid insurance.