Clinical Epidemiology (Jul 2020)

Platelet Count within the Normal Range at Hospital Admission is Associated with Mortality in Patients with Community-Acquired Pneumonia

  • Moulis G,
  • Christiansen CF,
  • Darvalics B,
  • Andersen IT,
  • Nørgaard M

Journal volume & issue
Vol. Volume 12
pp. 711 – 716

Abstract

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Guillaume Moulis, Christian Fynbo Christiansen, Bianka Darvalics, Ina Trolle Andersen, Mette Nørgaard Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, DenmarkCorrespondence: Guillaume MoulisDepartment of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Olof Palmes Allé 43-45, Aarhus N 8200, DenmarkTel +45 871 68205Fax +45 871 67215Email [email protected]: Apart from their hemostatic role, platelets are immune cells that play a role in fighting infections. The presence of thrombocytopenia and thrombocytosis at hospital admission are predictors of mortality in community-acquired pneumonia patients. We hypothesized that variations in platelet counts within the normal range also may be associated with mortality in these patients.Methods: The study included all adults in the North and Central Denmark Regions with a first acute hospital admission for community-acquired pneumonia during 2006– 2012. We assessed the association between the first platelet count within ± 24 hours of admission (within the normal range of 150 to 400 x 109/L) and 30-day mortality using Cox models. Analyses were adjusted for age, sex, Charlson Comorbidity Index score, hemoglobin level, leukocyte count, and creatinine level at admission.Results: Among the 12,905 study patients, 30-day mortality was 12.4%. The mean platelet count upon admission was 250 × 109/L. Compared with the 250– 275 × 109/L category, platelet counts of 151– 175 were associated with a lower 30-day mortality (adjusted hazard ratio [aHR]: 0.79, 95% confidence interval [CI]: 0.63– 0.99), while higher platelet counts were associated with a higher 30-day mortality (351– 375 × 109/L, aHR: 1.34, 95% CI: 1.07– 1.68; 376– 400× 109/L, aHR: 1.21, 95% CI: 0.94– 1.56).Conclusion: Platelet counts, even within the normal range, are associated with mortality in adult patients hospitalized for community-acquired pneumonia.Keywords: platelet count, thrombocytopenia, thrombocytosis, community-acquired pneumonia, mortality  

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