Table 3

Unadjusted and adjusted Cox PH models for RTI-related mortality at 1–4 years in England relative to Sweden in 2003–2012

Model 1Model 2Model 3
Country
 England1.58 (1.30 to 1.92)1.32 (1.09 to 1.61)1.30 (1.07 to 1.59)
 Sweden (baseline)111
Birth weight (g)
 500–14993.12 (2.02 to 4.83)2.99 (1.93 to 4.63)
 1500–24993.67 (2.78 to 4.84)3.50 (2.65 to 4.62)
 2500–34991.70 (1.43 to 2.02)1.66 (1.39 to 1.97)
 ≥3500 (baseline)11
Gestational age (weeks)
 <370.85 (0.64 to 1.13)0.86 (0.65 to 1.15)
 37–381.18 (1.00 to 1.41)1.20 (1.01 to 1.42)
 ≥39 (baseline)11
Sex
 Boy0.99 (0.86 to 1.13)0.98 (0.85 to 1.13)
 Girl (baseline)11
Congenital anomaly
 Yes28.42 (24.58 to 32.86)28.39 (24.55 to 32.82)
 No (baseline)11
Maternal age (years)
 <251.04 (0.86 to 1.25)
 25–290.92 (0.76 to 1.11)
 30–34 (baseline)1
 ≥350.81 (0.66 to 1.00)
Quintile of socioeconomic status
 Q1: most deprived1.28 (1.02 to 1.60)
 Q21.08 (0.85 to 1.36)
 Q31.07 (0.84 to 1.35)
 Q40.93 (0.73 to 1.19)
 Q5: least deprived (baseline)1
  • Data are adjusted HR with 95% CI. Each column represents a separate Cox PH model: model 1 was only adjusted for indicator of country with Sweden as baseline, model 2 was additionally adjusted for birth characteristics (birth weight, gestational age and presence of congenital anomalies), and model 3 was further adjusted for socioeconomic factors (socioeconomic status and maternal age).

  • PH, proportional hazards; RTI, respiratory tract infection.