Time-of-day and appendicitis: Impact on management and outcomes

Abstract

Background: Observational research has shown that delayed presentation is associated with perforation in appendicitis. Many factors that affect the ability to present for evaluation are influenced by time of day (eg, child care, work, transportation, and office hours of primary care settings). Our objective was to evaluate for an association between care processes or clinical outcomes and presentation time of day.

Methods: The study evaluated a prospective cohort of 7,548 adults undergoing appendectomy at 56 hospitals across Washington State. Relative to presentation time, patient characteristics, time to operation, imaging use, negative appendectomy, and perforation were compared using univariate and multivariate methodologies.

Results: Overall, 63% of patients presented between noon and midnight. More men presented in the morning; however, race, insurance status, comorbid conditions, and white blood cell count did not differ by presentation time. Daytime presenters (6 am to 6 pm) were less likely to undergo imaging (94% vs 98%, P < .05) and had a nearly 50% decrease in median preoperative time (6.0 h vs 8.7 h, P < .001). Perforation significantly differed by time-of-day. Patients who presented during the workday (9 am to 3 pm) had a 30% increase in odds of perforation compared with patients presenting in the early morning/late night (adjusted odds ratio 1.29, 95% confidence interval, 1.05-1.59). Negative appendectomy did not vary by time-of-day.

Conclusion: Most patients with appendicitis presented in the afternoon/evening. Socioeconomic characteristics did not vary with time-of-presentation. Patients who presented during the workday more often had perforated appendicitis compared with those who presented early morning or late night. Processes of care differed (both time-to-operation and imaging use). Time-of-day is associated with patient outcomes, process of care, and decisions to present for evaluation; this association has implications for the planning of the surgical workforce and efforts directed at quality improvement.

Figure 1. Patient Volume (as a Percentage of the Cohort) & Percent Perforation by Hour

The histogram depicts the percentage of the entire cohort that presented within each hour of the day (right sided Y-axis). The dark line overlying the histogram indicates the perforation rate by hour of presentation (left sided Y axis).

Figure 2. Boxplot: Time from Hospital Arrival to OR, by Time-of-Presentation

Figure 3. Percent Perforation by Time-of-Presentation

Time-of-Presentation is divided into three-hour periods. Patients presenting within each period were also stratified by whether the time elapsed from their presentation to their OR start was greater or less than the median; a perforation rate was calculated for each strata, which are represented by the dotted lines.