Table 2

Trends in hospitalisations for all-cause pneumonia, pneumococcal pneumonia and empyema in adults ≥18 years of age before and after introduction of 10-valent pneumococcal conjugate vaccine (PCV10) in the national infant vaccination programme, Finland

Outcome	Baseline rate in 2004–2005 (per 100 000 population)	Adjusted annual trends using interrupted time-series analysis
		Period before PCV10 (from 2004–2005 to 2009–2010*)			Period after PCV10 (from 2011–2012 to 2014–2015*)
		Annual trend			Annual trend
		IRR	95% CI	p†	IRR	95% CI	p†
All-cause pneumonia
Age (years)
18–49	167.9	1.012	0.988 to 1.037	0.075	0.908	0.876 to 0.953	<0.001
50–64	310.6	1.049	1.037 to 1.062	<0.001	0.908	0.876 to 0.930	<0.001
≥65‡	1639.8	1.018	1.013 to 1.023	<0.001	0.976	0.965 to 0.988	0.004
65–74	816.7	1.024	1.012 to 1.037	<0.001	0.965	0.942 to 0.988	0.016
75–84	2071.8	1.012	1.007 to 1.024	<0.001	0.976	0.965 to 1.002	0.081
≥85	4434.3	1.024	1.012 to 1.028	<0.001	0.988	0.965 to 1.012	0.375
Total‡	502.8	1.024	1.018 to 1.037	<0.001	0.953	0.942 to 0.965	<0.001
Pneumococcal pneumonia
Age (years)
18–49	5.7	1.037	1.002 to 1.087	0.029	0.855	0.775 to 0.953	0.003
50–64	10.4	1.062	1.024 to 1.087	0.001	0.855	0.785 to 0.930	<0.001
≥65‡	16.3	1.012	0.988 to 1.049	0.290	0.988	0.919 to 1.062	0.845
65–74	11.3	1.037	0.988 to 1.087	0.073	0.976	0.876 to 1.074	0.604
75–84	20.9	0.988	0.942 to 1.037	0.515	1.087	0.965 to 1.224	0.186
≥85	25.6	1.024	0.953 to 1.087	0.590	0.865	0.711 to 1.037	0.105
Total‡	9.1	1.037	1.012 to 1.049	<0.001	0.919	0.876 to 0.965	<0.001
Empyema
Age (years)
18–49	2.4	1.024	0.976 to 1.062	0.378	0.976	0.865 to 1.114	0.736
50–64	7.4	1.049	1.012 to 1.087	0.015	0.930	0.844 to 1.024	0.117
≥65‡	7.7	1.100	1.062 to 1.154	<0.001	0.919	0.844 to 1.012	0.074
65–74	8.9	1.100	1.037 to 1.154	<0.001	0.930	0.824 to 1.049	0.248
75–84	4.7	1.114	1.049 to 1.196	0.001	0.908	0.766 to 1.074	0.266
≥85	11.7	1.114	1.012 to 1.253	0.035	0.908	0.702 to 1.168	0.435
Total‡	4.8	1.062	1.037 to 1.087	<0.001	0.942	0.897 to 1.002	0.059

IRRs are adjusted for sex and seasonality, with the natural log of the population size as the offset variable. The IRR of the trend before PCV10 is estimated as the change in annual hospitalisation rates in the years 2004–2005 to 2009–2010. The IRR of the trend after PCV10 is estimated as the comparison of the annual trend in the years 2011–2012 to 2013–2014 to the trend in the period before.
*PCV10 was introduced in the Finnish NVP in September 2010. The year 2010–2011 was defined as a transitional period and was excluded from the analysis.
†Two-tailed p Value.
‡Analyses for the aggregate age groups (ie, the total (≥18 years of age) and the ≥65 years of age) were age adjusted using the following age groups: all age groups in the analyses for the total and the 65–74, 75–84 and ≥85 years of age in the analyses for the ≥65 years of age group.
IRR, incidence rate ratio; NVP, National Vaccination Programme.