Several measures of ICU performance have been proposed in the past 30 years. It is intuitive, and correct, to assume that ICU mortality may be a useful marker of quality. However, crude mortality rates does not take into consideration the singular aspects of each specific patient population that is treated in a certain geographic region, hospital or ICU. Therefore approaches looking for standardized mortality ratios that are adjusted for disease severity, comorbidities and other clinical aspects are often sought. Severity of illness is usually evaluated by scoring systems that integrates clinical, physiologic and demographic variables. Scoring systems are interesting tools to describe ICU populations and explain their different outcomes. The most frequently used are the APACHE II, SAPS II and MPM. However, newer scores as APACHE IV and SAPS III have been recently introduced in clinical practice. More than only using scoring systems, one should search for a high rate of adherence to clinically effective interventions. Adherence to interventions as deep venous thrombosis prophylaxis, reduction of ICU-acquired infections, adequate sedation regimens and decreasing and reporting serious adverse events are essential and have been accepted as benchmarking of quality.

The complex task of collecting and analyzing data on performance measures are made easier when clinical information systems are available. Although several clinical information systems focus on important aspects as computerized physician order entry systems and individual patient tracking information, few have attempted to gather clinical information generating full reports that provide a panorama of the ICU performance and detailed data on several domains as mortality, length of stay, severity of illness, clinical scores, nosocomial infections, adverse events and adherence to good clinical practice. Through implementing quality initiatives, increasing the quality of care and patient safety are major and feasible goals. Such systems are available for clinical use and may facilitate the process of care on a daily basis and provide data for an in-depth analysis of ICU performance.