Efficacy in Predicting Negative Appendectomy Rates in Operated Acute Appendicitis Patients Using the Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA) Score Versus Modified Alvarado Score

Introduction Acute appendicitis is the commonest abdominal surgical emergency globally. The most accepted management of acute appendicitis is surgical, either open or laparoscopic appendectomy. Overlapping clinical presentations with many genitourinary and gynecological conditions lead to difficulty in accurate diagnosis, making negative appendectomies an unwanted reality. With the advancement in technology, there have been constant efforts to minimize negative appendectomy rates (NAR) using imaging modalities like USG of the abdomen and the gold-standard imaging test, the contrast-enhanced computed tomography of the abdomen. Due to the cost incurred and the lesser availability of such imaging modalities and needed expertise in resource-poor settings, various clinical scoring systems were devised to accurately diagnose acute appendicitis and thereby decrease NAR. We conducted our study to determine the NAR between the Raja Isteri Pengiran Anak Saleha Appendicitis score (RIPASA) and the modified Alvarado (MA) scoring methods. Methods A prospective observational analytical study was conducted, including 50 patients presenting to our hospital with acute appendicitis and who underwent emergency open appendectomy. The need to operate was decided by the treating surgeon. Patients were stratified by both scores; the pre-operative scores were noted and were later compared with the histopathological diagnosis. Results A total of 50 clinically diagnosed patients with acute appendicitis were evaluated utilizing the RIPASA and the MA scores. The NAR was 2% using the RIPASA score vs 10% with the MA score. The sensitivity was 94.11% vs 70.58% (p<0.0001), the specificity was 93.75% vs 68.75% (p<0.0001), the positive predictive value (PPV) of 96.96% vs 82.75% (p<0.001), the negative predictive value (NPV) of 88.23% vs 52.38% (p<0.001), and NAR of 2% vs 10% (p<0.0001) in the RIPASA vs MA scoring method, respectively. Conclusions RIPASA score is highly efficacious and statistically significant in diagnosing acute appendicitis with higher PPV at higher scores and higher NPV with lower scores leading to decreased NAR compared with MA score.