Patient safety in hospital context: study of incidence and preventability of adverse events in a large hospital

Adverse events (AE) are defined as unintended injury or harm resulting in temporary or permanent disability or dysfunction, and/or prolonged hospital stay or death caused by health care provided, and there is no connection with the process of the patient's underlying disease. The rate of AE in the hospital setting is a relevant indicator for patient safety, as the complex combination of human processes, technologies, and interactions that integrate the healthcare system has important benefits, but at the same time leads to the risk of AE occurrence. In this scenario, this study aimed to analyze the incidence and preventability of AE related to health care in adult patients admitted to a large general hospital. This is a retrospective cohort study, in which the analysis of AE was based on a two-stage retrospective review of the medical records. The study target population consisted of adult patients admitted to the investigated hospital, from January to December 2015, with discharge/death in the same year, and the characteristics: aged at least 18 years; hospitalization with more than 24 hours of hospital stay or death in less than 24 hours; admission to the several units and/or medical specialties at the time of hospitalization, except psychiatry and obstetrics. Patients with unavailable medical records at the time of data collection and/or follow-up by the palliative care team registered in the medical record were excluded. To conduct a retrospective review of the medical records, a computerized version of the screening (first stage) and EA evaluation (second stage) forms were used. In the screening stage, health professionals performed an explicit assessment of medical records in order to track potential adverse events (pAE) as well as delineate the demographic, clinical and hospitalization profile of patients. The presence of at least one screening criterion (trigger) in this phase indicated the eligibility of the medical records for the second stage of the review. During the evaluation phase, physicians performed an implicit and structured assessment of the medical records to identify previously screened AE, checking some attributes of interest: incidence, preventability, severity, classification according to nature, length of hospital stay attributable to AE, type of error and causal factors. Of the 368 patients in the final sample, 166 had pAE, proceeding to the next stage. In the second stage, it was found that 149 patients suffered some type of incident (with or without harm). At the end, 266 AE related to health care were confirmed, which affected 124 patients. Thus, the incidence of AE related to health care provided corresponded to 33.7%. Length of hospital stay was identified as a risk factor for the occurrence of AE, since length of stay of eight days or more increased the risk of occurrence of AE by 1.2 times compared to hospitalizations with less than eight days (RR: 1.20; 95% CI: 1.04 - 1.39). AE were classified as: related to general care (22.6%); drug-related (18.8%); related to nosocomial infection (13.2%); related to the procedure (40.6%); related to the diagnosis (0.8%); and other types of AE (4.1%). Regarding the severity of AE, it was found that 63.2% were considered minor events, 20.7% moderate and 16.2% severe. Concerning the preventability of AE, it was estimated that 58.3% were preventable. Human error was responsible for most occurrences and errors of omission prevailed when compared to errors of commission. About the contributing factors for the occurrence of AE, the care provided was the main causal factor. This study provided an overview of the types of problems that permeate patient safety, guiding possible future interventions for the mitigation of specific AE and immediately supporting the promotion of a safety culture in health institutions. Knowledge about the incidence, nature, severity, and preventability of AE occurring in the hospital setting should be assimilated as a first step toward improving patient safety and quality in health care