The politics of inadequate registers. SIR,-Inaccuracy in address data is a serious weakness of population registers that undermines their usefulness for research, ...
The questions raised by Dr Cruickshank concern achieved blood pressure in individual patients. We obtained a stable reduction in diastolic blood pressure to below 90 mm Hg (treatment target) in 30 of the 41 patients receiving antihypertensive treatment. The following patients had a diastolic blood pressure >90 mm Hg: five of the nine patients with uraemia; two of three patients with myocardial infarction; and four of the 27 patients who survived. These figures indicate that seven of 14 patients who died durirr the studv had a sustained raised blood pressure despite antihypertensive treatment. tIANS-HENRIK PARVING EVA HOMMEL
Hvid(jre Hospital, DK-2930 Kiampenborg, Denmark I Knowles HC( Jr. t ong term usvenilc diabetes trcated with unmeasoired dict Trats .Assoc Amz I'hYsIsa(niats 1971;84:95-101. 2 Knowles HC Jr. Magnitude of' the rcnal faillire problent in diabetic patients. Kidney Int 1974;6 (stuppl :2-7. 3 Krolewski AS, W3arram JH, (hristlieb AR, Btusick EJ, Kahn CR. Trh changing natuiral history of ncphropathy in type I diabctes. .Am .Ied 1985 ;78: 785 94. 4 Andersen AR, Christiansen JS, Anderseii JK, Kreiner S, Deckert T. Diabetic nephropath\ in tN pe I (insulin-dependent) diabetes: an epidemiological sttuds. )iabeiolsila 1983;25:
496-501. 5 Parving H-H, Hommel E. Prognosis in diabetic nephropathv. _4rMeJ7 1989;299:230-3. :22 Jul\J 6 Blainey Jt), Brewer D13, Hardwickc J. Proteitiiiric glomertilar discasc in adtults: csimuilatise litf tibles oscr twentit svears. QjMe'd 1986;230:557-67.
in the proportion of addresses with faults. The variation was not random (X =360, df=9, p
