Conclusions This systematic review and meta‐ analysis provides evidence that vegetarian diets effectively lower blood concentrations of total cholesterol , low‐density lipoprotein cholesterol , high‐density lipoprotein cholesterol , and non – high‐density lipoprotein cholesterol .
Such diets could be a useful nonpharmaceutical means of managing dyslipidemia , especially hypercholesterolemia
Background Vegetarian diets exclude all animal flesh and are being widely adopted by an increasing number of people ; however , effects on blood lipid concentrations remain unclear .
This meta‐ analysis aim ed to quantitatively assess the overall effects of  vegetarian diets on blood lipids .
Discordance between reported intention-to-treat and per protocol analyses.
OBJECTIVE To quantify the degree of disagreement between the two most popular methods for dealing with missing data : intention to treat ( ITT ) and per protocol ( PP ) . STUDY DESIGN AND SETTING We performed a systematic review of r and omized two-armed clinical trials ( CTs ) published between 2001 and 2003 , abstract ed in PubMed and reporting both the ITT and PP analyses on a primary binary endpoint , out of which 74 papers were finally selected . The treatment effect of each CT was measured by the odds ratio , and the disagreement between them was quantified by the Bl and -Altman method . RESULTS On average , the PP estimator provides greater values Log(e)ORPP=1 x 25.Log(e)ORITT , ( 95 % CI : 1.15 , 1.35 ) than the corresponding ITT estimator , although the limits of concordance showed that the ratio between the two estimators varies greatly from 0.39 up to 2.53 . CONCLUSION These results confirm that missing values may cause both systematic and unpredictable bias in CTs . Further efforts should be made to minimize protocol deviations and to use better statistical methods to highlight the drawbacks of missing information . In the presence of protocol deviations , the conclusion of a CT can not rest on the single reporting of either the ITT or the PP approach alone
Conclusions This systematic review and meta‐ analysis provides evidence that vegetarian diets effectively lower blood concentrations of total cholesterol , low‐density lipoprotein cholesterol , high‐density lipoprotein cholesterol , and non – high‐density lipoprotein cholesterol .
Such diets could be a useful nonpharmaceutical means of managing dyslipidemia , especially hypercholesterolemia
Background Vegetarian diets exclude all animal flesh and are being widely adopted by an increasing number of people ; however , effects on blood lipid concentrations remain unclear .
This meta‐ analysis aim ed to quantitatively assess the overall effects of  vegetarian diets on blood lipids .