Prehospital comorbidity in 631 patients hospitalised with pandemic H1N1 infection during the first pandemic wave compared with national prevalence data
| Children (n=226) | Adults (n=405) | All admissions (n=631) | Background prevalence* (%) | |
| No. of comorbidities† | ||||
| 0 | 149 (66) | 198 (49) | 347 (55) | – |
| 1 | 66 (29) | 138 (34) | 204 (32) | – |
| ≥2 | 11 (5) | 69 (17) | 80 (13) | – |
| Comorbidity | ||||
| Cardiovascular disease | 5 (2) | 64 (16) | 69 (11) | 3.5 |
| Pulmonary disease | ||||
| COPD | 0 (0) | 25 (6) | 25 (4) | 1.5 |
| Asthma | 35 (16) | 124 (31) | 159 (25) | 5.9 |
| Other pulmonary disease | 8 (3) | 13 (3) | 21 (3) | - |
| Diabetes | 3 (1) | 48 (12) | 51 (8) | 4.1 |
| Other metabolic disease | 4 (2) | 2 (<1) | 6 (1) | - |
| Neurological disease | 9 (4) | 10 (3) | 19 (3) | - |
| Cerebrovascular disease | 0 (0) | 3 (<1) | 3 (<1) | 1.7 |
| Obesity recorded on admission | 0 (0) | 8 (2) | 8 (1) | 8.1‡ |
| Pregnancy | 0 (0) | 27 (7)§ | 27 (4) | 6.2¶ |
Data are number (%) unless otherwise indicated.
↵* National prevalence data on comorbidity were obtained from the Quality and Outcomes Framework (QOF) primary care data for 2009 (www.qof.ic.nhs.uk) and are based on all ages except for pregnancy.
↵† Recorded obesity and pregnancy are excluded from the number of comorbidities in the upper portion of the table.
↵‡ National prevalence data on obesity based on QOF obesity registers defined as body mass index ≥30 kg/m2.
↵§ 27 pregnancies represent 7% of all adults but 18% of women aged 16–44 years in the study.
↵¶ 6.2% of females aged 15–44 years estimated to be pregnant in source population: in addition to 207 474 live births in London, East Midlands and Northern Ireland in 2008, we assumed that 4% of females aged 15–44 years experienced miscarriage or abortion in the same time period (119 668). To calculate the prevalence of pregnancy we took 9/12 of annual live births (assuming 9-month duration of pregnancy) and 3/12 of miscarriages/abortions (assuming 3-month duration), divided by the total female population aged 15–44 years.
COPD, chronic obstructive pulmonary disease.