Table 1

Risk ratio (RR)* of headache related to blood pressure11 years earlier

All headache typesNon-migrainous headacheMigraine
VariableTotal numbernRR (95% CI)nRR (95% CI)nRR (95% CI)
*Adjusted for age, occupational status, and use of antihypertensive drug therapy.
Women:
    Systolic blood pressure (mm Hg)
        <140792630911.0 (reference)21681.0 (reference)9231.0 (reference)
        140–4910442480.8 (0.7 to 0.9)1840.8 (0.7 to 1.0)640.8 (0.6 to 1.1)
        ≥15017282890.7 (0.6 to 0.8)2220.7 (0.6 to 0.8)670.7 (0.5 to 1.0)
p for trend <0.0001p for trend <0.0001p for trend <0.01
    Diastolic blood pressure (mm Hg)
        <90827830331.0 (reference)21371.0 (reference)8961.0 (reference)
        90–9917844701.0 (0.9 to 1.1)3360.9 (0.8 to 1.1)1341.1 (0.9 to 1.4)
        ≥1006361250.8 (0.6 to 1.0)1010.8 (0.6 to 1.0)240.7 (0.4 to 1.1)
p for trend <0.05p for trend <0.01p for trend=0.44
Men:
    Systolic blood pressure (mm Hg)
        <140787919641.0 (reference)15391.0 (reference)4251.0 (reference)
        140–4920224200.9 (0.8 to 1.1)3210.9 (0.8 to 1.0)991.1 (0.8 to 1.3)
        ≥15020862950.8 (0.7 to 0.9)2250.7 (0.6 to 0.9)700.9 (0.7 to 1.3)
p for trend <0.0002p for trend <0.0005p for trend=0.25
    Diastolic blood pressure (mm Hg)
        <90819119391.0 (reference)15201.0 (reference)4191.0 (reference)
        90–9928045931.1 (1.0 to 1.2)4501.0 (0.9 to 1.2)1431.2 (1.0 to 1.5)
        ≥1009921470.8 (0.6 to 1.0)1150.8 0.6 to 1.0)320.8 (0.6 to 1.2)
p for trend=0.10p for trend <0.01p for trend=0.17