Arterial pressures in a general practice.

Systolic and diastolic readings of blood pressure were recorded for 5386 (2585 males and 2801 females) members of a general practice situated in and around Ballycastle, County Antrim. Polynomials to predict blood pressure from age were derived for systolic and diastolic pressures of males and females. Polynomials to predict blood pressure variance from age were derived for both systolic and diastolic pressure of each sex. Age-sex adjusted diastolic and systolic scores were calculated for each of the 5386 members of the practice using a technique similar to that reported by Hamilton et al. (1954 a, b).Parent-child correlations ranging from -0.21 to 0.17 were observed; however, when all sibships were considered together irrespective of size coefficients which were significantly greater than zero generally involved the mother of the child. No sib-sib correlation (all sibship sizes combined), except those involving twins exceeded the value 0.13. Husband-wife correlations were similar to the corresponding parent-offspring correlations when both husband and wife were aged 45 years or more. Generally speaking, the coefficients found in this study were lower than those of other workers and reasons are discussed why the estimates of the present paper may not be unbiased.