Risk factors for 90-day and 180-day mortality in hospitalised patients with pressure ulcers

An understanding of risk factors associated with mortality among pressure ulcer patients can inform prognostic counselling and treatment plans. This retrospective cohort study examined associations of comorbid illness, demographic characteristics and laboratory values with 90-day and 90- to 180-day mortality in adult hospitalised patients with pressure ulcers. Data were extracted from hospital databases at two academic urban hospitals. Covariates included mortality risk factors identified in other populations, including demographic and laboratory variables, DRG weight, 'systemic infection or fever' and comorbidity categories from the Charlson comorbidity index. In adjusted Cox proportional hazards models, diabetes, chronic renal failure, congestive heart failure and metastatic cancer were significantly associated with mortality in both time frames. There was no significant effect on mortality from dementia, hemiplegia/paraplegia, rheumatic disease, chronic pulmonary disease or peripheral vascular disease. Myocardial infarction, cerebrovascular disease, liver disease and human immunodeficiency virus/AIDS were associated with mortality in the 90-day time frame only. 'Systemic infection or fever' was associated with mortality in the 90-day time frame but did not show a confounding effect on other variables, and the only significant interaction term was with metastatic cancer. Albumin was the only studied laboratory value that was strongly associated with mortality. Understanding the context of comorbid illness in pressure ulcer patients sets the groundwork for more robust studies of patient- and population-level outcomes, as well as study of heterogeneity within this group.