Association between platelet count and 30-day mortality in community-acquired pneumonia patients receiving systemic glucocorticoids therapy.

Platelet count is a readily available hematological parameter that has been recognized as a potential indicator of inflammation and thrombosis. However, previous research has not examined the prognostic significance of platelet count in patients with community-acquired pneumonia (CAP) undergoing systemic glucocorticoid therapy. This study seeks to explore the correlation between admission platelet count and 30-day mortality rates among CAP patients who are under systemic glucocorticoids treatment. Data were sourced from the Dryad database. The study population included patients diagnosed with CAP who had received systemic glucocorticoids prior to hospitalization. Patients were stratified into tertiles based on their admission platelet count. We utilized multivariable Cox regression models to evaluate the independent effect of platelet count and 30-day mortality, with adjustments for potential confounding variables. Kaplan-Meier survival analysis was conducted to compare survival rates among these groups. Complementing the primary analyses, restricted cubic spline curves and subgroup analyses were implemented to appraise the association between platelet counts and 30-day mortality among diverse subgroups. Additionally, a sensitivity analysis was performed to substantiate the robustness of our findings. A total of 614 CAP patients were included in the study. The 30-day mortality rate was 21.3% (131/614). Platelet count exhibited a significant association with mortality. Multivariable Cox regression analysis indicated that higher platelet count was independently associated with reduced 30-day mortality (HR: 0.94, 95% CI: 0.92–0.97, P < 0.001), indicating that each per 10 × 109/L rise in platelet count was associated with a 6% reduce in mortality risk. This association remained significant after adjusting for potential confounders (HR: 0.96, 95% CI: 0.94–0.99, P = 0.002). Patients in tertile 2 demonstrated a non-significant trend toward reduced mortality (HR 0.60, 95% CI: 0.35–1.02, P = 0.061), whereas those in tertile 3 showed a significantly lower risks of 30-day mortality compared to tertile 1 (HR 0.51, 95% CI: 0.31–0.86, P = 0.012). Kaplan-Meier survival curves showed that patients in the highest platelet count tertile had the highest survival rates (log-rank test: P < 0.001). Subgroup analyses revealed consistent results across different subgroups. Platelet count was inversely linearly associated with 30-day mortality. Higher platelet count on admission is significantly associated with reduced 30-day mortality in CAP patients receiving systemic glucocorticoids. This finding suggests that platelet count could serve as a potential prognostic marker for early risk stratification and clinical decision-making in this patient population.