Effect of parenteral energy or amino acid doses on in-hospital mortality, among patients with aspiration pneumonia: a cohort medical claims database study

Background This study examined the association between parenteral energy/amino acid doses and in-hospital mortality among inpatients on long-term nil per os (NPO) status, using a medical claims database in Japan. Methods Hospitalized patients with aspiration pneumonia, aged ≥65 years and on >7-days NPO status, were identified in a medical claims database between January 2013 and December 2018. Using multivariate logistic regression and regression analyses, we examined the association between mean parenteral energy/amino acid doses and in-hospital mortality, and secondarily the association between prognosis (in-hospital mortality, inability to receive full oral intake, re-admission, hospital stay length) among four groups classified by mean amino acid dose (No dose: 0 g/kg/day; Very low dose: >0, ≤0.3 g/kg/day; Low dose: >0.3, ≤0.6 g/kg/day; Moderate dose: >0.6 g/kg/day). Results The analysis population included 20,457 inpatients (≥80 years: 78.3%). In total, 5,920 mortalities were recorded. Increased amino acid doses were significantly associated with reduced in-hospital mortality (p <0.001). With a No dose reference level, the odds ratios (95% confidence interval) of in-hospital mortality adjusted for potential confounders, were 0.78 (0.72–0.85), 0.74 (0.67–0.82), and 0.69 (0.59–0.81) for Very low, Low, and Moderate amino acid doses, respectively. Additionally, patients prescribed amino acid dose levels >0.6 g/kg/day had shorter hospitalization periods than those prescribed none. Conclusions Increased amino acid doses were associated with reduced in-hospital mortality. Sufficient amino acid administration is recommended for patients with aspiration pneumonia requiring NPO status.