Beyond the distance between juridic and scientific decision-making process: An evidence-based prediction algorithm for professional liability assessment in healthcare-associated infections.

Background: HAIs (Healthcare-Acquired-Infections) have been recently the subject of judgment n. 6386 pronounced on 3rd March 2023 by the Italian Supreme Court. This sentence provided three criteria to determine whether a health facility is responsible for the patient contracting a nosocomial infection, i.e. time criterion, topographical criterion and clinical criterion. Accordingly, the healthcare facility is obliged to prove the fulfillment of a series of preventive hygiene measures specifically detailed by the legislator. Herein, the positive predictive value of these criteria ("juridic criteria") in the identification of professional liability for nosocomial infections was evaluated in comparison with clinical criteria reviewed by Infectious Disease specialists ("Infectious-Disease criteria", i.e. presence of a Multidrug Resistant Organism (MDRO); development of surgical site infection; inadequate antibiotic therapy; inadequate disinfection).

Methods: Two retrospective cohorts were compared from the Portal of Telematic Services of the Ministry of Justice; 51 patients were extrapolated from Italian judgments concerning claims for Gram-negative nosocomial infections in the three-year period 2020-2022. On the other side, from the electronic database of University Hospital of Bari we extracted 349 patients affected by Gram-negative infections in the same timespan. Both "juridic" criteria and "Infectious-Disease" criteria were then applied to the full cohort after stratification for cohort of origin and after stratification for nosocomial or non-nosocomial infections. Predictive value of criteria was evaluated through receiver operating characteristic (ROC) curves and area under the curve (AUC).

Results: Overall, the incidence of definite nosocomial infections (according to final judgement or clinical records discharge letter) was 84 % in juridic cohort and 46 % in "real-world" series. Data suggested that the presence of all three juridic criteria [ROC AUC = 0.944 (95%CI = 0.924-0.963)] or the four clinical criteria [ROC AUC = 0.948 (95%CI = 0.928-0.969)] predicted well a case of nosocomial infection with professional liability. Moreover, by summarizing both criteria in a single classification system, the generated ROC curve (was the one with the highest AUC [0.9488 (95%CI = 0.928-0.969)]. Accordingly, further tests were performed, evaluating the predictive value of one juridic criterium plus at one of more Infectious-Disease criteria. Interestingly, the ROCs curves demonstrated that the presence of at least 1 juridic criteria plus at least 2 Infectious Disease criteria reached a predictive value comparable to 2 or 3 juridic criteria.

Conclusions: The results highlight the efficiency of new criteria laid down in the judgment of the Italian Supreme Court to attribute liability for nosocomial infection despite the disputed distance between juridic and scientific decision-making process. In addition, the use of a combined score combining "juridic" and "Infectious-Disease" criteria provides a high-quality tool to be used by technical consultants to make up for lack of clinical documentation by passing judgments concerning litigation about professional liability in case of nosocomial infections. This sheds light on the possibility to face worldwide judicial inquiries with scientific rigor.