E-drug: Re: 1999 WHO-ISH hypertension guidelines (cont'd)
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Jerome,
I accept your comments about the limitations of the SHEP study however I am
not convinced that lack of planning of a subgroup analysis of a major
endpoint is a strong criticism.
There is a problem with interpretation of the UKPDS 38 that you have not
mentioned: The report does not say what "other drugs" were used in the
"less tight control of blood pressure" group. It does say what was
recommended: "The suggested sequence was frusemide 20�mg daily (maximum 40
mg twice daily), slow release nifedipine 10�mg (maximum 40�mg) twice daily,
methyldopa 250�mg (maximum 500�mg) twice daily, and prazosin 1�mg (maximum
5�mg) thrice daily." If any of those drugs increased mortality (which is a
real possibility) then part or all of the apparent efficacy of ACE I an
Beta-blockers may be due to the comparator group getting worse results than
if they had been on a placebo.
By contrast as far as I can work out the 2 CAPPP (Please note three Ps)
trial sub group analyses for diabetics do provide evidence for the
superiority of captopril over diuretics / beta blockers for diabetics. If
beta blockers are equal then perhaps thiazides are inferior. However we do
not know how often thiazides were used in the diabetic subgroups. Perhaps
the problem is that hydrochlorothiazide was given at 25 mg per day when
perhaps it should be used at 12.5 mg per day?
I conclude that there is still cause for uncertainty.
regards,
Peter
Dr Peter Mansfield
Director, MaLAM
MaLAM encourages pharmaceutical companies to provide more reliable
information to assist appropriate health care.
MaLAM Headquarters
PO Box 172, Daw Pk SA 5041, Australia
phone/fax +61 8 8374 2245
peter.mansfield@flinders.edu.au
http://www.camtech.net.au/malam
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