A conference to assess related hospital nosocomial infections mortality; a multicenter study in 14 French hospitals

Background: Nosocomial infection (NI) is an adverse event with potentially lethal consequences.

Objective: The aim of this study was 1: to evaluate the number of deaths associated with NI, 2: their relative contribution and 3: the preventable trait of NI and death through a mortality conference.

Methods: The study was performed in 14 French hospitals (9,000 beds) on 13,537 consecutive deaths from january 2007 to december 2008. Patients with a Mac cabe score of 2 (predictive score of short-term mortality) or who died within 2 days after admission were excluded. Medical records of the 2,355 eligible patients were reviewed for cause of death, NI and disease severity, before admission and before NI onset. The contribution of NI to death was assessed by an expert comity including hospital physicians and nurses in charge of the patient. Attributable and preventable trait of NI and of death were respectively assessed according to a 6-category scale and a 4-category scale of probability.

Results: Among the 2,355 eligible patients, the median age was 78 years (q1-q3: 68-85), with a sex-ratio M:F = 1.13. Most of these patients came from medical wards (51%) or ICU (37%). Twenty three percent (552 patients) presented at least one nosocomial infection: 280 with pneumonia (51%), 117 with bacteremia (21%), 55 with urinary tract infection (10%), 33 with surgical site infection (6%), 33 with GI tract infection (6%), 9 with skin infection (1.6%), 8 with catheter related infection (1.4%), 7 with bone infection (1.3%) and 7 with other infections (1.4%). Enterobacteriacae (27.7%), Staphylococcus aureus (17.5%) and Pseudomonas aeruginosa (16.2%) were the most frequently identified microorganisms. The part of multidrug resistant bacteria was 56.9% for S. aureus (MRSA) and 15.8% for enterobacteria (ESBL). Mortality was attributable to NI for 182 patients (33.0% of NI, 1.3% of all the deaths) and estimated as preventable in 61 cases (11.1% of NI, .5% of all the deaths). Death was considered as preventable in 35 cases (6.3% of NI, 0.3% of all the deaths). Among them, 10 were attributable to a preventable NI in patients in which death was totally unexpected (1.8% of NI).

Conclusions: Based on a consensual and thorough review of each patient’s clinical story, this study confirms that NI is a leading cause of death and that a large part is preventable. If the same scale was used on a national level, the number of deaths attributable to NI in France would reach 3,500 (CI95%: 2,605-4,036). Among these attributable deaths, 1,300 NI (CI95%: 357-2,196) and 800 deaths (CI95%: 51-1,481) could be considered as preventable. To improve healthcare quality, mortality conferences are needed to identify circumstances that might be associated with severe NI contributing to death, and target as specifically as possible preventive measures. All healthcare workers must be associated to these mortality conferences.