Impacts of admission serum albumin levels on short-term and long-term mortality in hospitalized patients

Aim: The aim of this study is to assess the association between admission serum albumin and short- and long-term mortality in all hospitalized patients. Design: A single-center cohort study. Methods: A retrospective cohort of all adult hospitalized patients at a tertiary referral hospital between January 2009 and December 2013 were analysed. Admission serum albumin was stratified into six groups: <= 2.4, 2.5-2.9, 3.0-3.4, 3.5-3.9, 4.0-4.4 and >= 4.5g/dl. The outcomes of interest were in-hospital mortality, length of hospital stay and 1-year mortality. Serum albumin of 4-4.4g/dl was selected as a reference group for outcome comparison. Results: A total of 14 075 patients were studied. Admission serum albumin of >= 4.5g/dl had the lowest in-hospital and 1-year mortality with progressively increased in-hospital mortality observed with decreased admission serum albumin. In adjusted analysis, compared with serum albumin of 4.0-4.4 g/dl, serum albumin of <= 2.4, 2.5-2.9, 3.0-3.4 and 3.5-3.9 were significantly associated with increased in-hospital and 1-year mortality. In contrast, serum albumin of >= 4.5g/dl was significantly associated with lower 1-year mortality but not in-hospital mortality. Admission serum albumin <4.0g/dl was significantly associated with a prolonged hospital stay, while admission serum albumin of >= 4.5g/dl was significantly associated with shorter hospital stay, compared with serum albumin of 4.0-4.4 g/dl. Conclusion: Low albumin level at admission was progressively associated with increased short- and long-term mortality in all hospitalized patients even when albumin level was considered in normal range.