Assessing Risk-Factors for Hospital-Acquired Pressure Injuries and Impact to Cost and Outcomes in U.S. Hospitals

Background: Hospital-acquired pressure injuries (HAPI) are a societal burden with approximately 2.5 million pressure ulcers treated annually in the U.S., amounting to $11 billion in healthcare costs. The emergence of large-scale population level data from electronic medical records and claims data, offers the potential to generate further insight into risk factors through predictive modeling. Increasingly, the availability of such ‘big-data’ allow decision makers to move towards more evidence-based solutions to health system problems such as HAPI.

Methods: This study of inpatients from the 2009-2014 U.S. Premier Healthcare Database identified HAPI using ICD-9 diagnosis codes 707.xx. Comparisons of outcomes were made after 1:3 propensity score matching of HAPI to non-HAPI patients. Conditional logistic regression models compared odds for inpatient readmissions and generalized estimating equations models compared mean index visit LOS and costs.

Results: The study identified 16,967,687 adult inpatients (47,365 HAPI) during the study period. The matched sample included 110,808 patients (27,702 HAPI). Strong risk factors for HAPI included prior PU (OR=12.52, 95% CI 11.93-13.15), prior diabetic foot ulcer (OR=3.43, 95% CI 3.20-3.68), and malnutrition (OR=3.11, 95% CI 3.02-3.20). Adjusted mean LOS was 3.7 days longer (p<.0001), and total hospitalization cost $8,014 higher (p<.0001) for HAPI vs. non-HAPI patients. HAPI patients had greater odds of readmissions through 180-days follow-up (OR=1.60, 95% CI 1.55-1.65).

Conclusions: This study identified novel risk factors and highlighted the burden of HAPIs. In a dynamic and evolving healthcare system where the availability and usefulness of data advances daily, providers and policy-makers have an opportunity to leverage their own data on risk factors for HAPIs and the economic burden they place on society.