Summary: Blood pressure (BP) varies over a lifetime. This cardiovascular observation study (OS) compared the predictive value of earlier- and later-in-life blood pressure (BP) in 1,497 cardiovascular disease patients utilizing readings taken during a health survey (HS) and 15 years later from the same subjects at the baseline of this OS. Prediction of the cardiovascular risk during the OS follow-up (21 years) was significantly more effective if the earlier BP readings at HS were used instead of recent OS readings (NRI = 0.30, p