Table 4

Annual trends in microbiology results (in those admitted for pneumonia)

Initial % change per year (95% CI)Year of rate-change*Subsequent % change per year (95% CI)Direction of change†Estimate in 2014‡
Proportion of pneumonias with
 Blood or high-quality respiratory culture taken−3.9 (−5.5 to −2.2)2004−1.1 (−1.9 to −0.3)↓ ↓0.62
 Any potentially causative bacterial organism found−3.4 (−5.6 to −1.1)0.05
Incidence of pneumonia with
 Blood or high-quality respiratory culture taken2.1 (0.5 to 3.8)20077.2 (6.3 to 8.2)↑ ↑1024
 Any potentially causative bacterial organism found3.8 (1.3 to 6.3)78
S. pneumoniae−1.0 (−4.4 to 2.5)29
S. aureus0.2 (−8.4 to 9.6)5
E. coli9.8 (5.4 to 14.5)12
Klebsiella spp12.3 (4.8 to 20.2)5
P. aeruginosa8.6 (−5.6 to 25.0)3
H. influenzae4.5 (−7.7 to 18.3)3
 Other Enterobacteriaceae10.6 (4.4 to 17.3)6
 Anaerobes/S. Milleri13.6 (2.8 to 25.6)3
 Other Gram-positives2.3 (−1.5 to 6.3)8
 Other Gram-negatives35.0 (−16.6 to 118.6)1
 Mixed organisms7.8 (0.8 to 15.4)4
  • All trends modelled using piecewise linear Poisson regression.

  • *Allowing change in trend over time if significant improvement over linear trend alone (p<0.05), with year of the change point chosen by profile likelihood8 (see Methods).

  • †Single arrows represent direction of change over the whole time period; paired arrows represent direction and relative size of change in the periods before and after the year when data suggested trend in rates changed (as in *).

  • ‡Proportion/number of admissions, as estimated by the best-fitting model as presented in the table.