WP4.4 - Is it appendicitis? Keeping it SIMPLE

Abstract Aims Several appendicitis scoring systems have been described, criteria used for these are subjective leading to interobserver-bias. Existence of many scores instead of one suggests most of them are not clinically useful. We describe a SIMPLE score that is based on objective parameters as listed in Table 1. Methods A sample size for prospective evaluation was performed based on analysis of 118 patients of all ages with suspected appendicitis assessed at a University Hospital (area under ROC-curve of 0.7, null AUC 0.5, alpha 0.05, power 0.95). Each variable point weightage was calculated using multivariate analysis. ROC-analysis was used to define cut-offs for Leukocytes and CRP (GraphPad Prism-V9) as listed in Table -1. A SIMPLE-score was devised and prospectively validated. Results Table-1 SIMPLE-score Variable Odds ratio (95% CI) P-value Points Shift of abdominal pain 3.8 (1.3 – 12.1) 0.02 1 Impaired Oral intake 6.0 (1.5 – 31.5) 0.02 2 Mid-cycle 0.3 (0.0 – 2.1) 0.27 -1 Pyrexia of ≥37.5°C 2.5 (1.0 – 6.1) 0.04 1 Leukocytosis ≥10 5.5 (2.1 – 16.1) 0.00 2 Elevated CRP ≥9 4.0 (1.5 – 11.2) 0.01 2 SIMPLE score was calculated prospectively for 128 patients. Median age was 26.5 (range 4-85 years). Of these 62.5% (80) were females 37.5% (48) were males. A SIMPLE score of 2 or less was unlikely to be appendicitis (93.5% Negative Predictive Value), while a score of 3-6 was possibly appendicitis and a score of 7 or more was strongly associated with appendicitis (85% Positive Predictive Value). Conclusions SIMPLE score is objective, reliable, reproducible and indeed SIMPLE to use.