Effectiveness of lipid lowering drugs in general practiceBMJ 2003; 327 doi: https://doi.org/10.1136/bmj.327.7405.51-a (Published 03 July 2003) Cite this as: BMJ 2003;327:51
- Julia Hippisley-Cox, senior lecturer in general practice (, )
- Mike Pringle, professor of general practice,
- Carol Coupland, senior lecturer in medical statistics
EDITOR—Wang et al, and Kumana and Cheung are concerned by the omission of data on drug dosage. We included an analysis of drug dosage in the original paper submitted to the BMJ and removed it at the request of the editorial board. Of the 1116 patients whose serum cholesterol value was above 5 mmol/l, 209 (18.7%) were receiving maximum doses compared with 96 (7.1%) of the 1353 patients who did achieve the target range. In addition, in those patients receiving the maximum dose only 32% (96) achieved the target cholesterol value.
The table shows the number of patients taking each drug who reached target cholesterol values according to whether the maximum dose recommended in the British National Formulary had been prescribed. However, we have not looked at equivalent doses when these are submaximal for one drug, but maximal for another.
We did not write the statement “Statins reduce lipid levels better than fibrates”—this appeared in This week in the BMJ rather than in our paper. The text was different from the version we submitted, and we had no opportunity to comment on it before publication.
Kumana and Cheung raise the issue of differences between patients taking different statins. As we described in our paper, we took account of potential confounders by includingthe following variables in the multivariate analysis: sex, age, obesity, smoking status, pretreatment cholesterol values, comorbidity (ischaemic heart disease, diabetes, hypertension, and stroke), and registered general practices. We discussed the potential effect onthe results in our discussion.
We think that the “dispersion” mentioned by Wang et al refers to the 95% confidence intervals (which are not standard deviations), and naturally these are narrower for atorvastain and simvastatin because of the larger sample sizes in those groups.
Competing interests None declared.