Association between geriatric nutritional risk index and adverse outcomes in critical ill patients with chronic obstructive pulmonary disease: a cohort study of 2824 older adults

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide, particularly among the elderly, resulting in high rates of intensive care unit (ICU) admissions. Malnutrition is common in elderly patients and has been associated with poor prognosis in patients with COPD. However, its impact in the ICU setting remains incompletely defined. The objective of this study is to examine the association between malnutrition, as measured by the Geriatric Nutritional Risk Index (GNRI), and adverse outcomes in older patients with COPD in the ICU. A cohort study of 2,824 older COPD patients admitted to the ICU from 2008 to 2019 was conducted. The association between GNRI scores and outcomes including in-hospital mortality, risk of pressure injuries, and length of ICU stay was evaluated. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. A causal mediation analysis was employed to identify potential mediating variables and to calculate the proportion mediated. The median age of study participants was approximately 75 years, with 1,281 (45.4%) being female. Lower GNRI scores (GNRI ≤ 98) were significantly associated with increased in-hospital mortality (OR: 1.48, 95% CI: 1.08-2.05, p = 0.015), higher incidence of pressure injuries (OR: 1.97, 95% CI: 1.54-2.54, p