Practical score to aid decision making in doubtful cases of appendicitis.

During recent years different procedures have been used to assist in diagnosis of questionable cases of appendicitis. Among these methods, there are few scoring systems that have been shown to be effective. The aim of this study was to create a scoring system and to test its accuracy in the preoperative diagnosis of acute appendicitis. Clinical data from 360 patients who had undergone appendicectomy were collected to identify attributes that distinguished patients having a negative laparotomy from those with appendicitis. Seven independent criteria were identified. Using Bayesian methodology a weight was given to each criterion and an overall score calculated. A cut-off point was identified to separate patients for surgery and those for observation. The scoring system was applied prospectively to 166 consecutive patients; 134 had appendicitis and 32 a normal appendix (19.3 per cent error diagnosis). For the 166 patients the method suggested surgery in 113, 107 (94.7 per cent) of whom were found to have appendicitis. The system suggested observation in hospital in 38 cases. For the whole group the scoring system showed a sensitivity of 80 per cent and specificity of 81 per cent. Scoring systems from a local database could become the ideal complementary method in the diagnosis of suspected acute appendicitis.