Date of Award


Document Type


Degree Name

Master of Medicine (MMed)

First Supervisor/Advisor

Aidan Njau

Second Supervisor/Advisor

Omar Sherman

Third Supervisor/Advisor

Ahmed Jusabani


General Surgery (East Africa)


Background: Acute appendicitis is a common surgical emergency. In atypical presentation, making a clinical diagnosis is difficult leading to delays with high perforation rate or misdiagnoses and high negative appendectomy rates. In the urban referral hospitals in Tanzania the baseline perforation rate, negative appendectomy rate, and factors that drive it are unknown. These could serve as measures of performance, and as evaluation parameters of future interventions aimed at improving acute appendicitis case management in Tanzania.

Objectives: The aim of this study was to establish the negative appendectomy rate and associated factors among patients undergoing emergency appendectomy for suspected acute appendicitis in urban referral hospitals in Tanzania.

Methods: This was a cross-sectional study with 91 consecutive patients undergoing appendectomy for suspected acute appendicitis between May 2018 and April 2019.

Results: The negative appendectomy rate was found to be 38.5% and the perforation rate was 25.3%. Alvarado score was rarely applied (6%), and imaging investigations were used in almost all participants. Female gender was associated with higher negative appendectomy. Those who had computed tomography showed a lower negative appendectomy rate. Ultrasound was not useful in reduction of negative appendectomy rate. The established negative appendectomy rate was higher in our setting as compared to those reported internationally. Although computed tomography was shown to have a low corresponding negative appendectomy rate in this study, it was still significantly higher to those published in literature.

Conclusion: Alvarado score is underutilized despite demonstrated ability to decrease negative appendectomy rate. By applying the Alvarado score in these participants, negative appendectomy rate could have been reduced to 17%

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Surgery Commons