Table 3.
Adjusted RRs for blood pressure categories and adverse outcomes
| Normal blood pressure | Elevated blood pressure | Stage 1 hypertension | Non-severe stage 2 hypertension | Severe stage 2 hypertension | |
|---|---|---|---|---|---|
| Comparison with normal blood pressure category | |||||
| CLIP composite | 1 (ref) | 0·99 (0·94–1·03) | 1·08 (1·00–1·16)*† | 1·29 (1·13–1·47)† | 2·48 (2·06–2·98)† |
| Maternal composite | 1 (ref) | 1·02 (0·89–1·17) | 1·11 (0·93–1·33) | 1·20 (0·90–1·59) | 2·40 (1·60–3·59)† |
| Maternal CNS composite | 1 (ref) | 0·98 (0·63–1·51) | 1·26 (0·91–1·75) | 1·46 (1·00–2·13)† | 6·05 (3·88–9·46)† |
| Fetal or neonatal death | 1 (ref) | 0·93 (0·79–1·09) | 1·15 (0·96–1·38) | 1·48 (1·10–1·97)† | 4·09 (3·02–5·55)† |
| Stillbirth | 1 (ref) | 0·98 (0·74–1·29) | 1·24 (0·97–1·58) | 1·81 (1·30–2·54)† | 5·88 (3·95–8·73)† |
| Comparison of blood pressure category and all higher categories, with all lower blood pressure categories‡ | |||||
| CLIP composite | .. | 1·12 (1·05–1·19)† | 1·17 (1·09–1·26)† | 1·41 (1·24–1·60)† | 2·48 (2·06–2·98)† |
| Maternal composite | .. | 1·13 (0·96–1·33) | 1·17 (0·98–1·40) | 1·32 (1·05–1·65)† | 2·40 (1·60–3·59)† |
| Maternal CNS composite | .. | 1·32 (1·08–1·61)† | 1·47 (1·13–1·90)† | 1·91 (1·41–2·57)† | 6·05 (3·88–9·46)† |
| Fetal or neonatal death | .. | 1·20 (1·02–1·43)† | 1·33 (1·12–1·58)† | 1·75 (1·42–2·15)† | 4·09 (3·02–5·55)† |
| Stillbirth | .. | 1·36 (1·09–1·70)† | 1·52 (1·24–1·87)† | 2·19 (1·72–2·79)† | 5·88 (3·95–8·73)† |
Data are RR (95% CI). Blood pressure was categorised as: normal blood pressure (sBP <120 mm Hg and dBP <80 mm Hg), elevated blood pressure (sBP 120–129 mm Hg and dBP <80 mm Hg), stage 1 hypertension (sBP 130–139 mm Hg or dBP 80–89 mm Hg, or both), non-severe stage 2 hypertension (sBP 140–159 mm Hg or dBP 90–109 mm Hg, or both), or severe stage 2 hypertension (sBP ≥160 mm Hg or dBP ≥110 mm Hg, or both). RRs were estimated from modified Poisson and adjusted for maternal age, maternal basic education, gestational age at enrolment, and nulliparity. For outcome definitions, see the appendix (pp 3–4). RR=risk ratio. CLIP=Community-Level Interventions for Pre-eclampsia. sBP=systolic blood pressure. dBP=diastolic blood pressure.
Unrounded lower limit of 95% CI is 1·002.
95% CI does not overlap 1.
For example, for stage 1 hypertension, the comparison is for all women with sBP 130 mm Hg or greater or dBP 80 mm Hg or greater, or both, versus all women with sBP <130 mm Hg and dBP <80 mm Hg; the exception to this approach was for the normal blood pressure category which was compared with all higher blood pressure categories.