Tiss 76 and Tiss 28: correlation of two therapeutic activity indices on a Spanish multicenter icu database

Objectives: To evaluate the performance of the Simplified Therapeutic Inter vention Scoring System (TISS 28) on an independent database and to determin e its relation to the original Therapeutic Intervention Scoring System (TIS S 76). Design: Analysis of the database of the Spanish prospective multicenter stu dy PAEEC (Project for the Epidemiological Analysis of Critical Care Patient s). Setting: 86 intensive care units (ICUs) in Spain. Patients: Data on 8838 patients admitted to the ICUs. Measurements and results: Administrative data, main diagnostic category, se verity score [Acute Physiology and Chronic Health Evaluation (APACHE) II an d III] and data for the calculation of the TISS 76 and TISS 28 were collect ed during the first 24 h after the patient's ICU admission; TISS 76 and TIS S 28 scores were calculated and analyzed on how they Varied according to ot her variables (diagnostic group, severity level, hospital size and age). Th e association between TISS 76 and TISS 28 was studied. The TISS 76 score was 21 +/- 10.5 points and the TISS 28 score 23.3 +/- 8.8 points. There was a good correlation between TISS 76 and TISS 28 (r = 0.85 ). The regression equation was: TISS 28 = 8.35 +/- (0.712 x TISS 76). The T ISS 28 score behaved similarly to the TISS 76 score in relation to the othe r variables, with a positive correlation between the therapeutic and the se verity level (APACHE II and III) and a negative correlation between therape utic activity and age, with very similar correlation coefficients. Both TIS S 28 and TISS 76 scores were higher in larger hospitals. Conclusions: There is a strong correlation between TISS 28 and TISS 76 scor es in the PAEEC database and TISS 28 works correctly in our setting.