Scoring system to aid in diagnoses of appendicitis.

Problems related to the diagnosis of appendicitis are evidenced by the significant negative laparotomy rate. The present study sought to assess the feasibility of decreasing this diagnostic error by studying two groups of patients and identifying and weighing details of history, physical examination and laboratory findings utilizing 23 predictive factors. One hundred consecutive cases of proven appendicitis (AAp) were retrospectively reviewed and compared with 100 consecutive cases that had normal appendices removed because of erroneous preoperative diagnosis of appendicitis (NAp). Rates of occurrence for each predictive factor were determined separately for both groups. These were converted into weights which were then added to yield a diagnostic score for each patient. A cutoff point established the score which designated one group for observation and the other for surgery. Scores were assessed at three different points by balancing risks of missed diagnoses against benefits of avoiding unnecessary operations. Seven predictive factors had differentiating weights and reached statistical significance (p less than or equal to 0.05):-sex, age, duration of symptoms, GU symptoms, involuntary right lower quadrant muscle spasm, right-sided rectal mass, and white blood cell count. Using these seven predictors, at a "-3" cutoff, 38% NAPs would have been spared laparotomy and about 5% of the AAps would have been indicated for observation. Analysis indicated little risk in observing the 5% AAp (5/7 history less than or equal to 1 day), and progressive improvement for NAps with increasing time. This simple scoring system could have eliminated over one third of the unnecessary laparotomies in the present sample, indicating potential value as an aid in surgical decision-making.