CONCLUSIONS Antihypertensive treatment reduces the risk of mortality and cardiovascular morbidity in people with diabetes mellitus and a systolic blood pressure more than 140 mm Hg .
If systolic blood pressure is less than 140 mm Hg , however , further treatment is associated with an increased risk of cardiovascular death , with no observed benefit
OBJECTIVE To assess the effect of antihypertensive treatment on mortality and cardiovascular morbidity in people with diabetes mellitus , at different blood pressure levels .
Risk of bias versus quality assessment of randomised controlled trials: cross sectional study
Objectives To evaluate the risk of bias tool , introduced by the Cochrane Collaboration for assessing the internal validity of r and omised trials , for inter-rater agreement , concurrent validity compared with the Jadad scale and Schulz approach to allocation concealment , and the relation between risk of bias and effect estimates . Design Cross sectional study . Study sample 163 trials in children . Main outcome measures Inter-rater agreement between review ers assessing trials using the risk of bias tool ( weighted κ ) , time to apply the risk of bias tool compared with other approaches to quality assessment ( paired t test ) , degree of correlation for overall risk compared with overall quality scores ( Kendall ’s τ statistic ) , and magnitude of effect estimates for studies classified as being at high , unclear , or low risk of bias ( metaregression ) . Results Inter-rater agreement on individual domains of the risk of bias tool ranged from slight ( κ=0.13 ) to substantial ( κ=0.74 ) . The mean time to complete the risk of bias tool was significantly longer than for the Jadad scale and Schulz approach , individually or combined ( 8.8 minutes ( SD 2.2 ) per study v 2.0 ( SD 0.8 ) , P<0.001 ) . There was low correlation between risk of bias overall compared with the Jadad scores ( P=0.395 ) and Schulz approach ( P=0.064 ) . Effect sizes differed between studies assessed as being at high or unclear risk of bias ( 0.52 ) compared with those at low risk ( 0.23 ) . Conclusions Inter-rater agreement varied across domains of the risk of bias tool . Generally , agreement was poorer for those items that required more judgment . There was low correlation between assessment s of overall risk of bias and two common approaches to quality assessment : the Jadad scale and Schulz approach to allocation concealment . Overall risk of bias as assessed by the risk of bias tool differentiated effect estimates , with more conservative estimates for studies at low risk
CONCLUSIONS Antihypertensive treatment reduces the risk of mortality and cardiovascular morbidity in people with diabetes mellitus and a systolic blood pressure more than 140 mm Hg .
If systolic blood pressure is less than 140 mm Hg , however , further treatment is associated with an increased risk of cardiovascular death , with no observed benefit
OBJECTIVE To assess the effect of antihypertensive treatment on mortality and cardiovascular morbidity in people with diabetes mellitus , at different blood pressure levels .