TABLE 2

Bacterial pathogens detected in sputum samples by culture or PCR throughout study follow-up, during periods of stable disease (scheduled visits) and at exacerbation (AECOPD visits)

Bacterial speciesPercentage of bacteria-positive sputum samples (95% CI)
CulturePCR
Scheduled visits#AECOPD visitsScheduled visits+AECOPD visits§
Any74.2 (70.4–77.7)78.0 (72.1–83.2)67.0 (63.0–70.9)74.7 (68.3–80.5)
Haemophilus influenzae6.78.142.9 (38.7–47.0)39.7 (33.0–46.7)
Moraxella catarrhalis0.9 (0.3–1.9)3.3 (1.5–6.4)13.7 (11.0–16.8)26.8 (20.9–33.3)
Streptococcus pneumoniae2.5 (1.4–4.1)2.4 (0.9–5.1)16.8 (13.9–20.1)19.1 (14.0–25.0)
Streptococcus pyogenesNANA0.4 (0.1–1.1)1.0 (0.2–3.1)
Staphylococcus aureus3.1 (1.8–4.7)3.3 (1.5–6.4)10.6 (8.2–13.4)9.3 (5.7–13.9)
Pseudomonas aeruginosa8.5 (6.4–11.0)14.4 (10.0–19.5)16.3 (13.4–19.6)16.5 (11.7–22.1)
Klebsiella pneumoniae26.4 (22.8–30.1)24.9 (19.3–31.0)NANA
Acinetobacter baumannii2.2 (1.2–3.6)4.3 (2.1–7.6)NANA
Other47.7 (43.5–51.8)45.0 (38.3–51.8)NANA

#: n=554; : n=209; +: n=546; §: n=194. AECOPD: acute exacerbations of chronic obstructive pulmonary disease; NA: not assessed.