Biochemical prediction of gallstones in acute pancreatitis: a prospective study of three systems

Three clinicobiochemical systems have been proposed for predicting gallstones in acute pancreatitis based on one, three and five factors respectively, but have not been compared in a single prospective study. System 1 is based on the serum transaminase alone; system 2 uses alkaline phosphatase and bilirubin in addition to transaminase; and system 3 involves female gender, age, amylase and alkaline phosphatase in addition to transaminase. Over the 4-year period 1983-86, 368 patients with 391 episodes of acute pancreatitis had clinicobiochemical analysis within 48 h. Of these episodes, 220 were related to gallstones (56 per cent), 62 to alcohol (16 per cent) and 109 to other aetiologies or were idiopathic (28 per cent). Significant differences were found between the biliary and non-biliary groups with respect to sex (139 versus 59 women, P less than 0.002), age (65 +/- 17 versus 52 +/- 19 years, P less than 0.0001) and serum amylase (6041 +/- 6335 versus 4546 +/- 3990 units/l, P less than 0.0001), alkaline phosphatase (257 +/- 225 versus 141 +/- 137 units/l, P less than 0.0001), alanine transaminase (221 +/- 227 versus 72 +/- 119 units/l, P less than 0.0001) and bilirubin (40 +/- 39 versus 24 +/- 30 mumol/l, P = 0.0001). The sensitivity and specificity was 75 per cent and 74 per cent for the one-factor system, 74 per cent and 78 per cent for the three-factor system and 62 per cent and 80 per cent for the five-factor system. The predictive value of a positive result was 78.8 per cent, 81.5 per cent and 80.1 per cent and of a negative result 69.4 per cent, 70.1 per cent and 62.3 per cent for the three systems respectively. The performances of the one- and three-factor systems were marginally better than that of the five-factor system; the one-factor system, however, had the advantage of simplicity.