Clinical prediction rule for acute appendicitis in children in primary care

Guus Blok, Huib Burger, Johan Van Der Lei, Marjolein Berger, Gea Holtman

Keywords: Clinical Decision Rule, Appendicitis, Children

Background:

Recognising acute appendicitis in children presenting with acute abdominal pain in primary care is challenging. General practitioners (GPs) may benefit from a clinical prediction rule.

Research questions:

To develop and validate a clinical prediction rule for acute appendicitis in children presenting with acute abdominal pain in primary care.

Method:

A retrospective cohort study of data retrieved from GP electronic health records included in the Integrated Primary Care Information database was performed. We assigned children aged 4–18 years presenting with acute abdominal pain (≤7 days) to development (2010–2012) and validation (2013–2016) cohorts, using specialist-reported acute appendicitis as the outcome. Multivariable logistic regression was used to develop a prediction model based on clinical features from existing rules used in secondary care. We then performed internal and external temporal validation before deriving a point score with cut-offs for low-, medium-, and high-risk groups based on pre-defined sensitivity and specificity criteria.

Results:

The development and validation cohorts included 2041 and 3650 children, respectively, of whom 95 (4.6%) and 195 (5.3%) had acute appendicitis. The model included male sex, symptom duration (24–48, <24, >48 hours), nausea/vomiting, elevated temperature (≥37.3°C), abnormal bowel sounds, right lower quadrant tenderness, and peritoneal irritation. Internal and temporal validation showed good discrimination (C-statistics: 0.93 and 0.90, respectively) and excellent calibration. In the low-, medium-, and high-risk groups, the risks of acute appendicitis were 0.5%, 7.5%, and 41%, respectively.

Conclusions:

Combined with further testing in the mid-risk group, the prediction rule could improve clinical decision making and outcomes.

Points for discussion:

Why a clinical prediction rule rather than the present intuition based approach?

Would GPs use this prediction rule?

What is the next step for further research?

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