TABLE 2

Multivariable negative binomial regression model for respiratory tract infection hospitalisations

CharacteristicARR (95% CI)p-value
Time (per year)1.031 (1.028–1.033)
Smoke-free legislation0.965 (0.953–0.977)<0.001
Time since smoke-free legislation (per year)0.995 (0.991–0.999)0.017
Month
 JanuaryRef.
 February0.917 (0.904–0.930)
 March0.899 (0.887–0.912)
 April0.682 (0.672–0.693)
 May0.664 (0.654–0.674)
 June0.549 (0.540–0.557)
 July0.579 (0.571–0.588)
 August0.370 (0.364–0.377)
 September0.493 (0.486–0.501)
 October0.777 (0.766–0.789)
 November1.055 (1.040–1.070)
 December1.471 (1.451–1.492)
Sex
 FemaleRef.
 Male1.265 (1.257–1.273)
Age
 0–4 yearsRef.
 5–9 years0.129 (0.127–0.130)
 10–14 years0.055 (0.054–0.055)
Region
 Greater LondonRef.
 East Midlands1.798 (1.772–1.825)
 East of England1.462 (1.441–1.484)
 North East2.459 (2.422–2.497)
 North West2.288 (2.256–2.321)
 South East1.729 (1.705–1.754)
 South West1.682 (1.658–1.707)
 West Midlands1.955 (1.926–1.983)
 Yorkshire and the Humber2.032 (2.003–2.061)
Urbanisation level
 RuralRef.
 Urban1.008 (1.000–1.016)
Index of Multiple Deprivation
 Quintile 1#Ref.
 Quintile 21.082 (1.071–1.092)
 Quintile 31.202 (1.191–1.214)
 Quintile 41.336 (1.322–1.349)
 Quintile 51.497 (1.481–1.514)
  • ARR: admission rate ratio. #: least deprived; : most deprived.