Twenty-nine RCTs (n=8,432) were included: 19 fully published, eight published only as abstracts and two unpublished. The sample size varied from 10 to 1,548.
No studies were blinded and all reported Jadad scores of 2 or 3. In 2 studies disease severity at baseline differed between the two groups. All RCTs had follow-up rates of at least 80%.
When studies were pooled, there was no significant difference between tight glucose control and standard care for hospital mortality (RR 0.93, 95% CI: 0.85, 1.03; 27 RCTs) or need for new dialysis (RR 0.96, 95% CI: 0.76, 1.20; 8 RCTs).
Rates of septicaemia were significantly lower in the intervention group (RR 0.76, 95% CI: 0.59, 0.97; 9 RCTs), while rates of hypoglycaemia were significantly higher (RR 5.12, 95% CI: 4.09, 6.43; 15 RCTs).
Subgroup analyses showed that the significant effect of the intervention on septicaemia rate was observed only in the surgical ICU setting and not in medical or medical-surgical ICUs, and that very tight glucose control carried a higher risk of hypoglycaemia than moderately tight control.
Most subgroup and sensitivity analyses did not materially affect the results. Heterogeneity was noted in some subgroup analyses. The funnel plot showed no indication of publication bias for hospital mortality.