Evaluation of platelet lymphocyte ratio and 90-day mortality in patients with acute exacerbation of chronic obstructive pulmonary disease

Abstract

Background: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have high mortality and health care costs. The platelet to lymphocyte ratio (PLR) is a marker of inflammation and has been reported to be elevated in patients with AECOPD compared to stable state. In this study, we sought to evaluate the association of the PLR in patients with AECOPD with 90-day mortality.

Methods: We conducted a retrospective cohort study of patients admitted to our institution with a primary diagnosis of AECOPD between January 2014 and July 2014. Blood test results on admission were recorded. The primary outcomes were 90-day mortality.

Results: One hundred and eighty-one AECOPD patients were considered for the study. Death had occurred in 16 (9%) patients within 90 days of hospital discharge. Univariable analysis identified age, haemoglobin, neutrophil count, and urea level, neutrophil lymphocyte ratio (NLR) and PLR as being associated with increased 90-day mortality. Multivariable logistic regression analysis variables demonstrated that only PLR (P=0.03) was significantly associated with death at 90 days. Receiver operator characteristic analysis identified PLR ≥235 had a sensitivity of 63% and specificity of 74% in predicting 90-day mortality. PLR was ≥235 was also associated with worse survival (days) [mean ± standard deviation (SD): PLR ≥235 vs. PLR <235: 512±358 vs. 626±346, P=0.004].

Conclusions: A PLR ≥235 was significantly associated with 90-day mortality, which may provide prognostic guidance to clinicians.