Table 2

Annual trends in administrative data outcomes (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§
30-day mortality1.8 (0.4 to 3.1)2007−3.1 (−4.5 to −1.7)↑ ↓0.22
30-day readmission
 All-cause10.0 (4.2 to 16.1)20021.5 (0.4 to 2.6)↑ ↑0.16
 Pneumonia3.4 (1.7 to 5.2)0.04
Median length of stay (days)0.00 (−0.06 to 0.06)2006−0.25 (−0.30 to −0.20)↔ ↓4
  • Length of stay modelled using piecewise median regression, all other trends using piecewise linear Poisson regression.

  • *Percentage change in rate trend for mortality, readmission; absolute change in median length of stay.

  • †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 of admissions/median value, as estimated by the best-fitting model as presented in the table.