Division of Population Health Sciences Royal College of Surgeons in Ireland Coláiste Ríoga na Máinleá in Éirinn A Systematic Review and Meta-Analysis of the Alvarado Score in Predicting Acute Appendicitis Ohle R, O’Reilly F, O’Brien KK, Dimitrov BD, Fahey T.

CharacteristicPoints Migration of pain1 Anorexia1 Nausea1 Tenderness in right lower quadrant2 Rebound pain1 Elevated temperature1 Leucocytosis2 Shift of white blood cell count to the left1 Total DischargeObservationSurgery Alvarado score

Division of Population Health Sciences Objectives of systematic review 1. Meta-analysis of validation studies using the Alvarado CPR to determine its performance in predicting appendicitis 2. Estimate the diagnostic performance of the Alvarado CPR both as an admission criterion and a surgical criterion

Division of Population Health Sciences Methods

Division of Population Health Sciences Based on the 1986 Alvarado et al derivation study Number predicted by the Alvarado score to have appendicitis Number of observed to have appendicitis in each study Pooled results are presented as risk ratios(RR) RR>1 overprediction RR<1 underprediction by the rule RR=1 predicted equals observed Review manager 5 (cochrane collaboration) Mantel Haenszel random effects model Validation of the Alvarado score

Division of Population Health Sciences Data was extracted and 2x2 tables constructed for : low risk of appendicitis (1-4, 5-10) high risk (1-6,7-10) Men children, and women Results presented sensitivity & specificity with +/- likelihood ratios STATA software Ver.9 (mentandi command) Diagnostic performance

Division of Population Health Sciences Medline,Embase,Chochrane,DARE Keyword search appendicitis[MeSH], ‘alvarad*’, ‘alvorad*’, ‘Mantrels’, ‘score*’, ‘index’, ‘system’ and ‘criteria’ Search strategy

Division of Population Health Sciences Results

Division of Population Health Sciences 1. Validation

Low Risk (1-4)

Intermediate Risk (5-6)

High Risk (7-10)

Division of Population Health Sciences 2. Diagnostic Performance

Division of Population Health Sciences No. studies(n) Sensitivity (95% CI)Specificity(95% CI) +LR (95% CI) -LR (95% CI) Admission Alvarado score ≥ 5 Men50.96( )0.34( )1.46( )0.11( ) Women50.99( )0.35( )1.52( )0.35( ) Children60.94( )0.57( )2.15( )0.11( ) Admission Criterion : ≥ 5

Division of Population Health Sciences No. of studies(n) Sensitivity (95% CI)Specificity(95% CI) +LR (95% CI) -LR (95% CI) Surgery Men60.88( ) 0.57( ) 2.09( ) 0.20( ) Women70.86( ) 0.73( ) 3.19( ) 0.19( ) Children60.89( ) 0.74( ) 3.37( ) 0.15( ) Surgical Criterion : ≥ 7

Division of Population Health Sciences Conclusion

Division of Population Health Sciences The Alvarado score is a useful diagnostic CPR for men and children Application in women systematically over-predicts the probability of appendicitis Alvarado is useful as a criterion to “rule out” appendicitis in all patient groups Further diagnostic testing is needed prior to proceeding to surgery in high risk patients

Division of Population Health Sciences Clinical impact Reduce the number of unnecessary admissions Criteria for communication between surgeon and emergency department physician Reduce the number of unnecessary CT scans and thus reduce the time to operation In areas with no access to further imaging reduce the number of negative appendicectomy

Clinical Pathway Suspected Appendicitis Observation/ Investigation Alvarado Score DischargeSurgical consult

Division of Population Health Sciences Acknowledgements HRB centre for Primary Care Research Prof. T. Fahy Kirsty O’ Brien Borislav Dimitrov Grainne Cousins Conor Teljeur