Fig. 4From: Mental health, serum biomarkers and survival in severe COPD: a pilot studyKaplan Meier charts for leucocyte numbers (a) and PHQ-stress (b) using the respective median values as cut-off (leucocytes: median = 9.7 103/μl, p = 0.028; PHQ-stress: median = 6, p = 0.023). PHQ, Patient Health Questionnaire; SGRQ, St. George’s Respiratory Questionnaire; STAI, State-Trait Anxiety InventoryBack to article page