Association of Health Care Utilization With Rates of Perforated Appendicitis in Children 18 Years or Younger.

Importance: The pediatric perforated appendix rate is a quality metric measured by the Agency for Healthcare Research and Quality (AHRQ) that reflects access to care. The association of health care utilization prior to presentation with appendicitis is unknown. Objective: To determine whether increased health care utilization prior to presentation with appendicitis is associated with lower perforated appendicitis rates in children. Design, Setting, and Participants: Retrospective cohort study of privately insured children drawn from large employer and insurance company administrative data found in the Truven MarketScan national insurance claims database. Cases of appendicitis were identified among 38 348 children 18 years or younger from January 1, 2010, through December 31, 2013, with corresponding primary health care encounters from January 1, 2009, through December 31, 2012. In all, 19 109 eligible children were identified using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes for appendicitis after excluding those patients who did not have continuous insurance coverage during the study period. Statistical analysis was performed from September 1, 2016, to October 15, 2017. Exposures: Health care utilization was determined by the number of outpatient clinic encounters for each patient in the 1 to 12 months before presentation with appendicitis. Main Outcomes and Measures: Perforated appendicitis was defined according to the AHRQ by using ICD-9 codes for perforation and hospital length of stay of 3 or more days. Logistic regression models were used for perforated appendicitis after adjustment for age, sex, income, gastrointestinal comorbidities, geographic region, and insurance type. Results: We identified 38 348 children 18 years or younger with ICD-9 diagnosis codes for appendicitis, and 19 109 children remained for analysis after applying exclusion criteria. Of these, 11 422 were boys (59.8%); the mean (SD) age was 12.4 (3.9) years. Of the 19 109 children identified who underwent appendectomy, 5509 (28.8%) presented with perforated appendicitis. Children with perforation had lower outpatient health care utilization in the year before presentation compared with those diagnosed with acute appendicitis (4554 of 5509 children [82.7%] vs 11 937 of 13 600 [87.8%]; P < .001). In the adjusted model, outpatient health care utilization before presentation was associated with lower odds of perforated appendicitis (odds ratio [OR], 0.63; 95% CI, 0.58-0.69; P < .001). This association increased with visit frequency in the year before presentation (OR, 0.86; 95% CI, 0.77-0.95 for 1-2 visits, P = .003; OR, 0.61; 95% CI, 0.55-0.67 for 3-6 visits, P < .001; and OR, 0.43; 95% CI, 0.38-0.48 for ≥7 visits [5-18 years], P < .001). Covariates associated with perforation included younger age, geographic region, family income, and higher out-of-pocket insurance plans. Conclusions and Relevance: Among insured children 18 years or younger, increased health care utilization was associated with lower rates of perforated appendicitis. Primary health care relationships may facilitate timely presentation or serve as a marker for health-related self-efficacy, thereby contributing to outcomes for acute surgical conditions.