INTEROBSERVER VARIABILITY IN ULTRASOUND SCAN FOR SUSPECTED ACUTE APPENDICITIS

BACKGROUND: There is a global resolve among Clinicians towards adoption of imaging modalities in the evaluation of appendicitis because clinical algorithms have been disappointing. We sought to determine the authenticity of interobserver variability in ultrasound scan in a resource-constrained mission hospital settings, northwestern region of Cameroon. METHODS: In this study, we reviewed the standardized diagnostic approach in acute appendicitis and also performed prospective cross observational qualitative testing using sensitivity, specificity, positive predictive value, negative predictive value, and accuracy to determine the interobserver variability of ultrasonography using the medical database of the two Mission Hospitals, northwestern region of Cameroon from January 2012 to December 2016. A sequential non-randomized convenient sampling was used and data was analyzed using the Statistical Package for the Social Sciences version 22. RESULTS: A total of 103 patients who had pre-operative evaluation with Ultrasound scan and subsequently underwent surgery with histo-pathological examination of the removed appendix were analyzed. Their ages ranged from 15 to 65 years with a mean age of 30.6±18. There were 62 males and 41 females with a ratio of 1.5:1. Of the 103 patients, (n=90; 87.4%) cases were diagnosed as AA by histopathology while (n= 9; 8.7%) cases were negative. Ultrasound was positive in (n=75; 72.8%) cases, equivocal in (n=16; 15.5%), and negative in (n=10; 10.4%) cases. Sensitivity of ultrasound from this study when compared with ultrasound as the gold standard was 90.2% with a specificity of 85.6%; while Overall accuracy was 72.4%. Age and gender had no significant relationship with the accuracy of ultrasound in this study (p value=0.2 and 0.7 respectively). CONCLUSION: Ultrasound scan is more useful in detecting than in ruling out appendicitis. The radiological criteria for acute appendicitis, the accuracy of various imaging modalities and the limitations of the available research are described in this series. The interobserver variability in the ultrasonography evaluation of appendicitis is of significant impact in resource- limited surgical emergency settings like ours, which is a rural tropical population in the developing country.