The accuracy of the Alvarado score in predicting acute appendicitis in the black South African population needs to be validated

Abstract

E121 RESEARCH • RECHERCHEThe accuracy of the Alvarado score in predicting acute appendicitis in the black South African population needs to be validated Background: The Alvarado score is the most widely used clinical prediction tool to facilitate decision-making in patients with acute appendicitis, but it has not been validated in the black South African population, which has much wider differential diagnosis than developed world populations. We investigated the applicability of this score to our local population and sought to introduce a checklist for rural doctors to facilitate early referral. Methods:We analyzed patients with proven appendicitis for the period January 2008 to December 2012. Alvarado scores were retrospectively assigned based on patients' admission charts. We generated a clinical probability score (1-4 = low, 5-6 = intermediate, 7-10 = high). Results:We studied 1000 patients (54% male, median age 21 yr). Forty percent had inflamed, nonperforated appendices and 60% had perforated appendices. Alvarado scores were 1-4 in 20.9%, 5-6 in 35.7% and 7-10 in 43.4%, indicating low, intermediate and high clincial probability, respectively. In our subgroup analysis of 510 patients without generalized peritonitis, Alvarado scores were 1-4 in 5.5%, 5-6 in 18.1% and 7-10 in 76.4%, indicating low, intermediate and high clinical probability, respectively. Conclusion:The widespread use of the Alvarado score has its merits, but its applicability in the black South African population is unclear, with a significant proportion of patients with the disease being potentially missed. Further prospective validation of the Alvarado score and possible modification is needed to increase its relevance in our setting. Contexte :Le score d'Alvarado est l'outil de prédiction clinique le plus couramment utilisé pour faciliter la prise de décision chez les patients présentant une appendicite aiguë, mais il n'a pas été validé dans la population noire sud-africaine chez qui le diagnostic différentiel est beaucoup plus vaste que dans les populations des pays industrialisés. Nous avons exploré l'applicabilité de ce score à notre population locale et tenté de présenter une liste de vérification aux médecins ruraux pour accélérer les demandes de consultation. Conclusion : L'utilisation répandue du score d'Alvarado a ses mérites, mais son applicabilité dans la population noire d'Afrique du Sud est indéterminée, la maladie risquant de passer inaperçue chez une proportion significative de patients. Il faudra procéder à une validation prospective plus approfondie du score d'Alvarado et le modi fier peut-être si l'on veut en accroître la pertinence dans notre contexte. Méthodes

The Alvarado score versus computed tomography in the diagnosis of acute appendicitis: A prospective study

“…8 Other studies failed to prove the benefit of AS in ruling out AA and suggested that ethnic difference may account for this. 9,10 Our results were in concordance with a similar study performed on similar population in the Middle East.…”

Acute appendicitis in the developing world is a morbid disease

“…18 The classic textbook presentation is relatively uncommon. Although sophisticated imaging technology has allowed early diagnosis in many centres in the developed world, this is often not available in the developing world.…”

Increased anatomic severity in appendicitis is associated with outcomes in a South African population

“…Patients with aappendicitis in South Africa have increased rates of perforation and poorer outcomes (22). Reduced access to advanced imaging techniques, and inability of power prognostic clinical decision making tools (Alvarado score) to aid clinicians at primary care facilities, in addition to the patient behavior patterns and environment are all factors contributing to this increased anatomic severity (23). …”

“…This is important as the lack of a uniform system of classifying severity has made it difficult to provide universal evidence based recommendations for acute appendicitis. Previous scoring systems, such as the Alvarado score, are only utilized for diagnosis and not the measurement of severity, which is a distinct advantage that the AAST grading system offers (23,26). An operative severity classification like the AAST grading system is a more accurate and meaningful method to direct disease specific research and interventions rather than simple binary approach of simple versus complicated disease.…”