Risk factors for increased in-hospital mortality: a cohort study among cardiac surgery patients

BACKGROUND: Mortality is an important healthcare index for assessing the quality and the effectiveness of the provided nursing care. AIM: The aim of this study was to identify the risk factors for increased in-hospital mortality among cardiac surgery patients. METHODS: We followed up prospectively 313 consecutive patients who were admitted to the cardiac surgery intensive care unit (ICU) of a general, tertiary hospital in Athens during a 1 year period. Data collection was performed by using a short questionnaire and two instruments, the Nursing Activities Score (NAS) and the logistic EuroSCORE for assessing the nursing workload (NWL) and the perioperative risk for each patient respectively. RESULTS: Patients with a high 1st day NAS had an almost 3.3 times greater probability of death during their hospitalization (OR 3.3, 95%CI 1.4-8). Moreover, patients with increased perioperative risk (OR 4.2, 95%CI 1.50-12) and ICU length of stay (ICU-LOS) (OR 16.8, 95%CI 4.8-58.6) had statistically significant higher in-hospital mortality. CONCLUSION: Increased level of NWL, patient perioperative risk and ICU-LOS are closely associated with increased in-hospital mortality of cardiac surgery patients. The correlation between NWL and mortality represents the strong link of the nursing profession with the improvement of the effectiveness and quality of care.