Demographic characteristics of 1520 UK patients hospitalised with pandemic H1N1 infection during the 2009–2010 pandemic compared with source population and pre-pandemic hospital data on acute respiratory infection admissions
| n (%) | UK population comparison, % | Pre-pandemic hospital data, acute respiratory infections,* % | |
| Sex† | |||
| Men | 720 (47.4) | 48.7 | 50.4 |
| Women | 800 (52.6) | 51.3 | 49.6 |
| Age (years)‡ | |||
| <1 | 121 (8.0) | 1.3 | 14.7 |
| 1–4 | 138 (9.1) | 4.8 | 12.6 |
| 5–15 | 221 (14.5) | 12.6 | 4.8 |
| 16–24 | 245 (16.1) | 12.1 | 2.5 |
| 25–34 | 242 (15.9) | 12.9 | 3.3 |
| 35–44 | 195 (12.8) | 14.6 | 4.6 |
| 45–54 | 168 (11.0) | 13.5 | 5.4 |
| 55–64 | 115 (7.6) | 11.8 | 7.9 |
| 65–74 | 55 (3.6) | 8.5 | 11.0 |
| >75 | 20 (1.3) | 7.8 | 33.2 |
| Ethnicity§ | |||
| White | 630 (41.5) | 92.1 | 83.3 |
| Mixed | 11 (0.7) | 1.2 | 1.9 |
| Asian/Asian British | 249 (16.4) | 4.0 | 8.7 |
| Black/black British | 129 (8.5) | 2.0 | 3.4 |
| Chinese and other | 121 (8.0) | 0.8 | 2.7 |
↵* Hospital Episodes Statistics data: primary discharge codes relating to possible influenza admissions (J06, J10, J11, J13-22) were considered for the pre-pandemic influenza active period November 2008–March 2009.
↵† Census 2001 data for comparison of sex (KS01 tables) were obtained from the Office for National Statistics (ONS) (http://www.statistics.gov.uk).
↵‡ Demographic data on age distribution based on 2009 mid-year population estimates (ONS).
↵§ Ethnicity data from ONS (Census 2001 data, 2001 data from the General Register Office for Scotland and Northern Ireland Statistics and Research Agency).
Missing data for 380 (25%).