Perinatal, sociodemographic, and socioeconomic factors predicting hospital inpatient admissions, days, and costs (£1998–99) by age 10, determined by multiple regression (n = 93657)
| Independent variable | Category | Hospital admissions | Hospital days | Hospital costs | |||
|---|---|---|---|---|---|---|---|
| Adjusted effect (95% CI) | p Value | Adjusted effect (95% CI) | p Value | Adjusted effect (95% CI) | p Value | ||
| *Reference category. | |||||||
| Social class | I | 1.00* | 1.00* | 1.00* | |||
| II | 1.04 (1.04, 1.05) | <0.01 | 1.03 (1.02, 1.03) | <0.01 | 1.07 (1.06, 1.07) | <0.01 | |
| III-NM | 1.32 (1.31, 1.32) | <0.01 | 1.21 (1.18, 1.24) | <0.01 | 1.60 (1.59, 1.61) | <0.01 | |
| III-M | 1.19 (1.18, 1.19) | <0.01 | 1.12 (1.08, 1.16) | <0.01 | 1.34 (1.32, 1.35) | <0.01 | |
| IV | 1.17 (1.17, 1.17) | <0.01 | 1.15 (1.14, 1.15) | <0.01 | 1.32 (1.31, 1.33) | <0.01 | |
| V | 1.27 (1.26, 1.27) | <0.01 | 1.20 (1.19, 1.21) | <0.01 | 1.50 (1.49, 1.53) | <0.01 | |
| Parity | Nulliparous | 1.00* | 1.00* | 1.00* | |||
| Multiparous | 1.05 (1.04, 1.06) | <0.01 | 1.01 (1.00, 1.02) | 0.07 | 1.05 (1.03, 1.06) | <0.01 | |
| Missing | 0.93 (0.87, 0.99) | 0.02 | 0.90 (0.90, 1.02) | 0.16 | 0.87 (0.79, 0.96) | 0.01 | |
| Mother’s weight at first antenatal visit | 45–89 kg | 1.00* | 1.00* | 1.00* | |||
| <45 kg | 0.99 (0.95, 1.04) | 0.68 | 1.00 (0.95, 1.05) | 0.98 | 1.00 (0.93, 1.07) | 0.95 | |
| >89 kg | 1.07 (1.03, 1.11) | <0.01 | 1.04 (1.00, 1.08) | 0.02 | 1.11 (1.05, 1.18) | <0.01 | |
| Missing | 0.97 (0.96, 0.98) | <0.01 | 0.98 (0.97, 1.00) | 0.04 | 0.96 (0.94, 0.98) | <0.01 | |
| Cigarettes smoked per day by mother during pregnancy | None | 1.00* | 1.00* | 1.00* | |||
| 1–9 | 1.09 (1.07, 1.12) | <0.01 | 1.05 (1.03, 1.07) | <0.01 | 1.14 (1.11, 1.18) | <0.01 | |
| 10–19 | 1.13 (1.11, 1.14) | <0.01 | 1.07 (1.06, 1.09) | <0.01 | 1.20 (1.17, 1.23) | <0.01 | |
| 20+ | 1.16 (1.14, 1.19) | <0.01 | 1.09 (1.07, 1.11) | <0.01 | 1.26 (1.22, 1.30) | <0.01 | |
| Missing | 1.02 (1.01, 1.04) | <0.01 | 1.02 (1.00, 1.04) | 0.02 | 1.06 (1.03, 1.08) | <0.01 | |
| Mother hospital days during pregnancy | None | 1.00* | 1.00* | 1.00* | |||
| 1–10 | 1.03 (1.02, 1.04) | <0.01 | 1.01 (1.00, 1.02) | 0.01 | 1.06 (1.04, 1.07) | <0.01 | |
| 11–20 | 1.14 (1.09, 1.19) | <0.01 | 1.09 (1.04, 1.13) | <0.01 | 1.26 (1.18, 1.35) | <0.01 | |
| >20 | 1.16 (1.10, 1.23) | <0.01 | 1.08 (1.02, 1.14) | 0.01 | 1.32 (1.21, 1.43) | <0.01 | |
| Missing | 1.01 (0.98, 1.05) | 0.52 | 0.98 (0.94, 1.01) | 0.18 | 1.01 (0.95, 1.07) | 0.71 | |
| Complications during delivery | No | 1.00* | 1.00* | 1.00* | |||
| Yes | 1.01 (1.00, 1.03) | 0.01 | 1.01 (1.00, 1.02) | 0.03 | 1.04 (1.02, 1.06) | <0.01 | |
| Mother operated upon during delivery | No | 1.00* | 1.00* | 1.00* | |||
| Yes | 1.02 (1.00, 1.04) | 0.04 | 1.02 (1.00, 1.03) | 0.07 | 1.04 (1.01, 1.07) | 0.01 | |
| Mode of delivery | Spontaneous | 1.00* | 1.00* | 1.00* | |||
| Instrumental | 1.03 (1.01, 1.04) | <0.01 | 1.02 (1.00, 1.03) | 0.02 | 1.05 (1.03, 1.08) | <0.01 | |
| Caesarean | 1.10 (1.08, 1.12) | <0.01 | 1.10 (1.08, 1.12) | <0.01 | 1.23 (1.20, 1.27) | <0.01 | |
| Missing | 0.99 (0.94, 1.04) | 0.74 | 1.00 (0.95, 1.05) | 0.95 | 0.99 (0.92, 1.07) | 0.87 | |
| Multiple delivery | No | 1.00* | 1.00* | 1.00* | |||
| Yes | 1.01 (0.97, 1.04) | 0.67 | 1.01 (0.98, 1.04) | 0.41 | 1.07 (1.02, 1.13) | <0.01 | |
| Gestational age at birth | ⩾37 weeks | 1.00* | 1.00* | 1.00* | |||
| 32–36 weeks | 1.40 (1.36, 1.43) | <0.01 | 1.41 (1.38, 1.44) | <0.01 | 1.81 (1.74, 1.87) | <0.01 | |
| 28–31 weeks | 2.06 (1.92, 2.20) | <0.01 | 1.34 (1.25, 1.43) | <0.01 | 3.50 (3.15, 3.89) | <0.01 | |
| <28 weeks | 2.70 (2.39, 3.04) | <0.01 | 1.76 (1.55, 1.99) | <0.01 | 4.60 (3.80, 5.59) | <0.01 | |
| Missing | 0.77 (0.69, 0.87) | <0.01 | 0.93 (0.83, 1.04) | 0.19 | 0.70 (0.59, 0.84) | <0.01 | |
| Small for gestational age | No | 1.00* | 1.00* | 1.00* | |||
| Yes | 1.15 (1.13, 1.17) | <0.01 | 1.07 (1.05, 1.09) | <0.01 | 1.27 (1.23, 1.31) | <0.01 | |
| Missing | 1.40 (1.25, 1.56) | <0.01 | 1.13 (1.01, 1.27) | 0.03 | 1.63 (1.37, 1.94) | <0.01 | |
| Maternal age at time of delivery | 20–35 years | 1.00* | 1.00* | 1.00* | |||
| <20 years | 1.07 (1.05, 1.10) | <0.01 | 1.06 (1.03, 1.08) | <0.01 | 1.12 (1.09, 1.16) | <0.01 | |
| >35 years | 0.95 (0.93, 0.97) | <0.01 | 0.98 (0.96, 1.00) | 0.04 | 0.93 (0.90, 0.96) | <0.01 | |
| Missing | 0.98 (0.91, 1.05) | 0.60 | 1.02 (0.95, 1.10) | 0.56 | 0.98 (0.88, 1.10) | 0.73 | |
| Child adopted or fostered | No | 1.00* | 1.00* | 1.00* | |||
| Yes | 0.72 (0.64, 0.81) | <0.01 | 0.77 (0.69, 0.87) | <0.01 | 0.63 (0.52, 0.76) | <0.01 | |
| Birth cohort (period) | Unit change | 0.98 (0.97, 0.98) | <0.01 | 0.96 (0.96, 0.97) | <0.01 | 0.95 (0.94, 0.96) | <0.01 |
| Child’s survival period (age) | Unit change per year | 0.95 (0.95, 0.96) | <0.01 | 0.80 (0.80, 0.81) | <0.01 | 0.58 (0.58, 0.59) | <0.01 |
| Interaction of social class and child’s survival | I*survival | 1.00* | 1.00* | 1.00* | |||
| II*survival | 1.00 (1.00, 1.00) | 0.94 | 1.00 (0.99, 1.00) | 0.75 | 1.00 (0.99, 1.01) | 0.99 | |
| IIINM*survival | 0.99 (0.99, 1.00) | <0.01 | 0.99 (0.98, 0.99) | <0.01 | 0.98 (0.97, 0.99) | <0.01 | |
| IIIM*survival | 0.99 (0.99, 1.00) | <0.01 | 0.99 (0.99, 1.00) | 0.01 | 0.99 (0.98, 1.00) | 0.02 | |
| IV*survival | 0.99 (0.98, 0.99) | <0.01 | 0.99 (0.98, 0.99) | <0.01 | 0.97 (0.97, 0.98) | <0.01 | |
| V*survival | 0.98 (0.97, 0.98) | <0.01 | 0.98 (0.97, 0.99) | <0.01 | 0.96 (0.95, 0.97) | <0.01 | |
| Value in previous year | Unit change per year | 0.95 (0.95, 0.95) | <0.01 | 1.31 (1.30, 1.31) | <0.01 | 1.17 (1.17, 1.17) | <0.01 |