4.1. The patient safety approach of the pressure Ulcer and Fall Rate Quality Composite Index
Hospital-acquired pressure ulcer and total fall rates, as well as the Pressure Ulcer and Fall Rate Quality Composite Index, fit within a commonly used framework to assess patient safety that of an injury-based approach, which has the goal of eliminating patient harm (Scanlon et al., 2008). Scanlon et al. argue that “although injury-based metrics might aid the prevention of harm, limitations include poor discrimination of preventability, resulting in mis- directed interventions, missed opportunities, and disregard for the systems-based nature of unsafe health care” (p.1). They proposed a framework that is risk-based in which hazard identification and control are the focus. However, the purpose of our composite indicator is different.
We would argue that rather than disregarding system-based factors underlying adverse outcomes, the composite nature of our index allows us to measure systemic or structural aspects of a unit's quality of care with more sensitivity than risk-based measures related to any single adverse outcome (e.g., count of hospital-acquired pressure ulcer risk-reduction methods imple- mented for a patient) would allow. In the absence of risk-based quality measures for every adverse outcome, measuring a unit's overall quality with a set of indicators ideally more than two, with the Pressure Ulcer and Fall Rate Quality Composite Index an initial example is the only way to identify units with high and low overall quality and investigate what factors make them different. Further, there are not good risk-based safety metrics for falls, so that approach isn't an option.
It also is worth noting that risk- and injury-based approaches to safety measurement are not mutually exclusive but complemen- tary. The success of any risk-based prevention method (e.g., CLABSI checklist) can only be assessed by observing its effect on the rate of injury or harm. In terms of Donabedian’s framework, a focus on improving structures or processes of care to reduce risk must be accompanied by a measurable effect on outcomes—i.e., injury or harm.