Background
Methods
Data sources
Hospital discharge data
Death certificate data
Influenza activity data
Demographic data
Statistical analysis
Case definition
Hospitalizations coded as due to Influenza
Excess hospitalization and mortality
Cost estimation
Ethical considerations
Results
Descriptive statistics for unmodeled hospitalizations and deaths
Hospitalizations coded as due to Influenza
Hospitalization rate
Season | N | Ratec | Influenza as primary diagnosis (%) | Mean LoS (days) | In-hospital case fatality risk (%) | Use of supple-mental oxygen (%) | Use of non-invasive MV (%) | Use of invasive MV (%) | Mean hospitalization cost per patiente (€) | With comor-bidities (%) |
---|---|---|---|---|---|---|---|---|---|---|
2008/ 2009 | 117 | 22.8 | 86.3 | 4.4 | 0.0 | 17.9 | 0.9 | 0.9 | 780 | 5.1 |
2009/ 2010 | 617 | 123.5 | 82.7 | 5.1 | 0.2 | 17.8 | 0.6 | 2.1 | 1,232 | 8.4 |
2010/ 2011 | 158 | 32.2 | 74.7 | 6.6 | 0.6 | 34.2 | 3.2 | 3.2 | 1,576 | 5.7 |
2011/ 2012 | 128 | 26.6 | 68.0 | 6.8 | 0.0 | 31.3 | 1.6 | 4.7 | 1,295 | 17.2 |
2012/ 2013 | 122 | 26.3 | 73.8 | 6.6 | 0.8 | 41.8 | 3.3 | 4.9 | 2,471 | 13.1 |
2013/ 2014 | 180 | 40.0 | 70.0 | 7.0 | 0.0 | 32.2 | 3.3 | 1.1 | 1,253 | 10.0 |
2014/ 2015 | 154 | 35.3 | 66.2 | 5.3 | 0.0 | 32.5 | 3.2 | 1.3 | 967 | 12.3 |
2015/ 2016 | 340 | 79.4 | 75.3 | 6.0 | 0.3 | 38.2 | 2.4 | 2.9 | 1,307 | 12.9 |
2016/ 2017 | 170 | 39.9 | 70.0 | 6.3 | 0.0 | 40.6 | 2.9 | 1.8 | 1,209 | 12.4 |
2017/ 2018 | 333 | 77.4 | 76.0 | 5.9 | 0.0 | 33.0 | 5.1 | 1.8 | 1,005 | 10.8 |
9-year meana | 189 | 41.3 | 73.6 | 6.1 | 0.2 | 34.3 | 3.1 | 2.4 | 1,278 | 11.2 |
3-year meanb | 281 | 65.6 | 74.5 | 6.0 | 0.1 | 36.7 | 3.6 | 2.3 | 1,174 | 12.0 |
Variable | Age Group (in months) | Aged < 5 years old with comorbidities | Aged < 5 years old without comorbidities | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
0–5 | 6–11 | 12–23 | 24–35 | 36–47 | 48–59 | < 24 | 24–59 | 0–59 | |||
Share of hospitalizations (% of hospitalizations) | |||||||||||
9 years meana | 32.5 | 17.7 | 24.0 | 11.8 | 8.1 | 5.8 | 74.3 | 25.7 | 100.0 | 11.2 | 88.8 |
3 years meanb | 30.4 | 18.7 | 25.1 | 12.2 | 7.5 | 6.0 | 74.3 | 25.7 | 100.0 | 12.0 | 88.0 |
Hospitalization rate (hospitalizations per 100,000 children)c | |||||||||||
9 years meana | 139.4 | 75.7 | 50.3 | 24.5 | 16.5 | 11.6 | 78.6 | 17.4 | 41.3 | NA | NA |
3 years meanb | 196.7 | 121.4 | 81.7 | 40.2 | 25.0 | 19.9 | 120.4 | 28.4 | 65.6 | NA | NA |
Mean LoS (in days) | |||||||||||
9 years meana | 6.1 | 6.3 | 6.4 | 5.7 | 6.4 | 4.6 | 6.2 | 5.7 | 6.1 | 12.8 | 5.2 |
3 years meanb | 5.2 | 6.5 | 7.1 | 5.5 | 6.0 | 5.1 | 6.2 | 5.6 | 6.0 | 11.9 | 5.2 |
In-hospital case fatality risk (% of hospitalizations) | |||||||||||
9 years meana | 0.0 | 0.0 | 0.0 | 0.5 | 0.7 | 1.0 | 0.0 | 0.7 | 0.2 | 0.5 | 0.1 |
3 years meanb | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 2.0 | 0.0 | 0.5 | 0.1 | 0.0 | 0.1 |
Use of supplemental oxygen (% of hospitalizations) | |||||||||||
9 years meana | 28.3 | 44.2 | 39.4 | 35.3 | 30.4 | 19.2 | 35.7 | 30.1 | 34.3 | 48.7 | 32.4 |
3 years meanb | 29.7 | 46.8 | 42.9 | 35.0 | 28.6 | 27.5 | 38.5 | 31.3 | 36.7 | 51.5 | 34.6 |
Use of non-invasive mechanical ventilation (% of hospitalizations) | |||||||||||
9 years meana | 5.2 | 2.7 | 1.2 | 2.5 | 3.6 | 1.0 | 3.3 | 2.5 | 3.1 | 7.9 | 2.5 |
3 years meanb | 6.3 | 2.5 | 1.4 | 2.9 | 4.8 | 2.0 | 3.7 | 3.2 | 3.6 | 6.9 | 3.1 |
Use of invasive mechanical ventilation (% of hospitalizations) | |||||||||||
9 years meana | 3.6 | 2.0 | 1.7 | 1.5 | 1.4 | 3.0 | 2.6 | 1.8 | 2.4 | 9.9 | 1.5 |
3 years meanb | 2.7 | 1.9 | 2.4 | 1.0 | 1.6 | 3.9 | 2.4 | 1.8 | 2.3 | 8.9 | 1.3 |
Mean hospitalization cost per patientd(€) | |||||||||||
9 years meana | 1,678 | 1,282 | 925 | 1,050 | 1,165 | 1,048 | 1,339 | 1,086 | 1,278 | 3,812 | 953 |
3 years meanb | 1,150 | 1,513 | 1,008 | 1,171 | 940 | 1,095 | 1,194 | 1,086 | 1,174 | 2,612 | 972 |
Demographic and clinical characteristics
Severity indicators
Direct cost
Influenza-associated excess hospitalization
Estimated excess hospitalization
2008/ 2009 | 2009/ 2010 | 2010/ 2011 | 2011/ 2012 | 2012/ 2013 | 2013/ 2014 | 2014/ 2015 | 2015/ 2016 | 2016/ 2017 | 2017/ 2018 | ||
---|---|---|---|---|---|---|---|---|---|---|---|
P&I | N | 119 | 570 | 183 | 40 | -b | 259 | 84 | 278 | 101 | 215 |
95% CI | 40–207 | 512–629 | 115–262 | -28 to 103 | -266 to -119 | 198–312 | 27–135 | 207–334 | 40–155 | 132–281 | |
Ratea | 23.0 | 112.6 | 37.0 | 8.2 | -b | 56.8 | 19.0 | 64.4 | 23.8 | 50.1 | |
R | N | -b | 95 | -b | -b | -b | 367 | -b | 646 | -b | 652 |
95% CI | -1313 to -658 | -171 to 374 | -1147 to -533 | -412 to 99 | -1740 to -1158 | 152–596 | -1287 to -817 | 373–895 | -382 to 109 | 351–929 | |
Ratea | -b | 18.8 | -b | -b | -b | 80.5 | -b | 149.3 | -b | 152.2 | |
R&C | N | -b | 93 | -b | -b | -b | 381 | -b | 652 | -b | 662 |
95% CI | -1339 to -689 | -176 to 371 | -1166 to -556 | -405 to 105 | -1754 to -1169 | 165–613 | -1,292 to -820 | 377–909 | -387 to 105 | 364–942 | |
Ratea | -b | 18.3 | -b | -b | -b | 83.4 | -b | 150.8 | -b | 154.7 | |
All-cause | N | -b | -b | 922 | 214 | -b | -b | -b | 743 | -b | -b |
95% CI | -2442 to -1097 | -994 to 145 | 323–1576 | -428 to 862 | -4506 to -3112 | -1718 to -516 | -1934 to -928 | 72-1382 | -1380 to -335 | -1147 to 297 | |
Ratea | -b | -b | 186.4 | 44.0 | -b | -b | -b | 171.8 | -b | -b |
Estimated direct cost from the excess hospitalization
Influenza-associated excess mortality
2008/ 2009 | 2009/ 2010 | 2010/ 2011 | 2011/ 2012 | 2012/ 2013 | 2013/ 2014 | 2014/ 2015 | 2015/ 2016 | 2016/ 2017 | 2017/ 2018 | ||
---|---|---|---|---|---|---|---|---|---|---|---|
P&I | N | -c | |||||||||
95% CI | |||||||||||
Ratea | |||||||||||
R | N | 4.0 | 0.5 | 4.7 | -b | -b | 0.0 | -b | -b | -b | 0.1 |
95% CI | 3.2–5.7 | -1.0 to 2.1 | 4.1–7.1 | -2.9 to 1.4 | -2.9 to 2.0 | -0.5 to 2.1 | -0.9 to 1.6 | -0.8 to 2.7 | -1.8 to 1.2 | 1.3-5.0 | |
Ratea | 0.8 | 0.1 | 0.9 | -b | -b | 0.0 | -b | -b | -b | 0.0 | |
R&C | N | 4.3 | 0.3 | 4.6 | -b | -b | 1.5 | 1.5 | 0.4 | -b | 1.1 |
95% CI | 2.6–5.9 | -1.7 to 2.4 | 2.9–6.7 | -3.2 to 2.6 | -2.7 to 2.4 | -0.2 to 3.6 | 0.4–3.4 | -1.0 to 3.5 | -1.4 to 2.1 | 0.3–4.8 | |
Ratea | 0.8 | 0.1 | 0.9 | -b | -b | 0.3 | 0.3 | 0.1 | -b | 0.3 | |
All-cause | N | 9.2 | 7.8 | 7.0 | 21.0 | 8.4 | 9.0 | 7.4 | 15.5 | 6.4 | 3.1 |
95% CI | -2.9 to 20.4 | -3.5 to 19.8 | -4.4 to 18.3 | 10.1 to 31.7 | -4.0 to 20.9 | -1.3 to 18.7 | -1.4 to 15.8 | 4.1 to 25.7 | -2.3 to 15.0 | -9.5 to 15.6 | |
Ratea | 1.8 | 1.5 | 1.4 | 4.3 | 1.8 | 2.0 | 1.7 | 3.6 | 1.5 | 0.7 |