Use of a modified Alvorado score in the diagnosis of acute appendicitis

The negative appendicectomy rates have remained high. The integration of clinical scores into the diagnostic process in acute appendicitis has had the purposes of improving decision making and reducing the negative rates in this common condition. The performance of these score systems have however, not been uniform.

To assess the usefulness of a modified Alvorado score (1986) to predict groups of patients with suspected appendicitis for definite surgery, observation or discharge from hospital.

Prospective study.

Kenyatta National Hospital (KNH), a central referral and teaching hospital in Nairobi, Kenya.

One hundred and eighty nine patients with suspected acute appendicitis were studied over a period of twelve months.

Five symptoms and four signs were assigned numerical values and the patients scored out of a total of 10 points. A score of >7 predicted mandatory operation, 5-6 observation and score 1-4 predicted those not considered for surgery. The decision to operate was the prerogative of the surgeon or surgical resident based on overall clinical suspicion and not the diagnostic score.

The proportion of patients with scores >7 was 40.7%. The mean score was 6.02. The mean ages and the gender ratios were similar across score groups. The negative appendicectomy rate was 17.6% for group 1-4, 16.5% for 5-6 and 19.7% for >7. These were similar to the overall negative rate of 18% based on clinical suspicion. The overall sensitivity and sensitivity for the scoring system was 80.3% and 16.8% respectively.

High scores were found to perform poorly in predicting diagnosis of acute appendicitis preoperatively and in the reduction of negative appendicectomies. The integration of a scoring system does not offer advantage over degree of clinical suspicion.