The reporting quality of SRs has improved 3 y after publication of SR reporting st and ards , but the reporting of nutrition variables has not .
Improved adherence to consensus methods and reporting st and ards should improve the utility of nutrition SRs
BACKGROUND The quality of nutrition-related systematic review s ( SRs ) is an unstudied but important factor affecting their usefulness .
OBJECTIVES The objectives were to evaluate the reporting quality of published SRs and to identify areas of improvement .
Baseline characteristics and the effect of selenium supplementation on cancer incidence in a randomized clinical trial: a summary report of the Nutritional Prevention of Cancer Trial.
The Nutritional Prevention of Cancer Trial was a r and omized , clinical trial design ed to evaluate the efficacy of selenium as selenized yeast ( 200 microg daily ) in preventing the recurrence of nonmelanoma skin cancer among 1312 residents of the Eastern United States . Original secondary analyses through December 31 , 1993 showed striking inverse associations between treatment and the incidence of total [ hazard ratio ( HR ) = 0.61 , 95 % confidence interval ( CI ) = 0.46 - 0.82 ] , lung , prostate , and colorectal cancer and total cancer mortality . This report presents results through February 1 , 1996 , the end of blinded treatment . Effect modification by baseline characteristics is also evaluated . The effects of treatment overall and within subgroups of baseline age , gender , smoking status , and plasma selenium were examined using incidence rate ratios and Cox proportional hazards models . Selenium supplementation reduced total ( HR = 0.75 , 95 % CI = 0.58 - 0.97 ) and prostate ( HR = 0.48 , 95 % CI = 0.28 - 0.80 ) cancer incidence but was not significantly associated with lung ( HR = 0.74 , 95 % CI = 0.44 - 1.24 ) and colorectal ( HR = 0.46 , 95 % CI = 0.21 - 1.02 ) cancer incidence . The effects of treatment on other site-specific cancers are also described . The protective effect of selenium was confined to males ( HR = 0.67 , 95 % CI = 0.50 - 0.89 ) and was most pronounced in former smokers . Participants with baseline plasma selenium concentrations in the lowest two tertiles ( < 121.6 ng/ml ) experienced reductions in total cancer incidence , whereas those in the highest tertile showed an elevated incidence ( HR = 1.20 , 95 % CI = 0.77 - 1.86 ) . The Nutritional Prevention of Cancer trial continues to show a protective effect of selenium  on cancer incidence , although not all site-specific cancers exhibited a reduction in incidence . This treatment effect was restricted to males and to those with lower baseline plasma selenium concentrations
The reporting quality of SRs has improved 3 y after publication of SR reporting st and ards , but the reporting of nutrition variables has not .
Improved adherence to consensus methods and reporting st and ards should improve the utility of nutrition SRs
BACKGROUND The quality of nutrition-related systematic review s ( SRs ) is an unstudied but important factor affecting their usefulness .
OBJECTIVES The objectives were to evaluate the reporting quality of published SRs and to identify areas of improvement .