Multivariable negative binomial regression model for upper and lower respiratory tract infection (RTI) hospitalisations
| Characteristic | Upper RTIs | Lower RTIs | ||
| ARR (95% CI) | p-value | ARR (95% CI) | p-value | |
| Time (per year) | 1.018 (1.015–1.020) | 1.066 (1.059–1.072) | ||
| Smoke-free legislation | 1.019 (1.005–1.032) | 0.005 | 0.862 (0.844–0.880) | <0.001 |
| Time since smoke-free legislation (per year) | 0.981 (0.977–0.985) | <0.001 | 1.002 (0.994–1.009) | 0.701 |
| Month | ||||
| January | Ref. | Ref. | ||
| February | 1.053 (1.037–1.069) | 0.801 (0.783–0.820) | ||
| March | 1.094 (1.077–1.110) | 0.713 (0.696–0.730) | ||
| April | 0.851 (0.838–0.865) | 0.538 (0.525–0.551) | ||
| May | 0.860 (0.846–0.873) | 0.463 (0.451–0.475) | ||
| June | 0.728 (0.716–0.740) | 0.358 (0.348–0.367) | ||
| July | 0.770 (0.758–0.783) | 0.370 (0.360–0.380) | ||
| August | 0.513 (0.505–0.522) | 0.222 (0.216–0.229) | ||
| September | 0.663 (0.652–0.674) | 0.336 (0.327–0.345) | ||
| October | 0.987 (0.972–1.002) | 0.597 (0.583–0.612) | ||
| November | 1.098 (1.082–1.115) | 1.038 (1.015–1.061) | ||
| December | 1.311 (1.292–1.331) | 1.584 (1.550–1.618) | ||
| Sex | ||||
| Female | Ref. | Ref. | ||
| Male | 1.311 (1.303–1.320) | 1.219 (1.207–1.232) | ||
| Age | ||||
| 0–4 years | Ref. | Ref. | ||
| 5–9 years | 0.135 (0.134–0.136) | 0.130 (0.128–0.131) | ||
| 10–14 years | 0.056 (0.055–0.056) | 0.057 (0.056–0.058) | ||
| Region | ||||
| Greater London | Ref. | Ref. | ||
| East Midlands | 2.226 (2.192–2.261) | 1.412 (1.378–1.447) | ||
| East of England | 1.739 (1.712–1.766) | 1.203 (1.175–1.233) | ||
| North East | 3.081 (3.032–3.131) | 1.816 (1.770–1.862) | ||
| North West | 2.985 (2.942–3.029) | 1.564 (1.528–1.602) | ||
| South East | 2.079 (2.048–2.110) | 1.385 (1.353–1.417) | ||
| South West | 1.940 (1.910–1.971) | 1.447 (1.413–1.482) | ||
| West Midlands | 2.466 (2.429–2.504) | 1.462 (1.427–1.497) | ||
| Yorkshire and the Humber | 2.456 (2.419–2.493) | 1.631 (1.593–1.670) | ||
| Urbanisation level | ||||
| Rural | Ref. | Ref. | ||
| Urban | 1.030 (1.022–1.038) | 0.959 (0.947–0.972) | ||
| Index of Multiple Deprivation | ||||
| Quintile 1# | Ref. | Ref. | ||
| Quintile 2 | 1.099 (1.087–1.110) | 1.061 (1.044–1.078) | ||
| Quintile 3 | 1.227 (1.215–1.240) | 1.166 (1.147–1.185) | ||
| Quintile 4 | 1.356 (1.341–1.370) | 1.280 (1.259–1.302) | ||
| Quintile 5¶ | 1.523 (1.507–1.540) | 1.418 (1.392–1.444) | ||
ARR: admission rate ratio. #: least deprived; ¶: most deprived.