We have identified efforts by research ers to investigate interventions which seek to improve information delivery and consideration of information to enhance  informed consent .
The interventions used consistently improve patient knowledge , an important prerequisite for informed consent .
This is encouraging and these measures could be widely employed although we are not able to say with confidence which types of interventions are preferable .
Our results should be interpreted with caution due to the high levels of heterogeneity associated with many of the main analyses although we believe there is broad evidence of beneficial outcomes for patients with the pragmatic application of interventions .
BACKGROUND Achieving informed consent is a core clinical procedure and is required before any surgical or invasive procedure is undertaken .
However , it is a complex process which requires patients be provided with information which they can underst and and retain , opportunity to consider their options , and to be able to express their opinions and ask questions .
There is evidence that at present some patients undergo procedures without informed consent being achieved .
OBJECTIVES To assess the effects on patients , clinicians and the healthcare system of interventions to promote informed consent for patients undergoing surgical and other invasive healthcare treatments and procedures .
AUTHORS ' CONCLUSIONS Informed consent is an important ethical and practical part of patient care .
Take-home informed consent for intravenous contrast media: do patients learn more?
RATIONALE AND OBJECTIVES In 1978 , Morrow et al published the results of a simple technique for raising radiation oncology patients ' levels of awareness about medical options . They reported that providing written information at least 24 hours in advance was an effective tool for increasing the baseline knowledge in this patient group . However , Morrow 's cohort consisted exclusively of cancer patients receiving radiation therapy .  The authors of this article are concerned with whether the encouraging results reported by Morrow are reproducible when applied to patients awaiting invasive radiologic procedures . METHODS One hundred sixty consecutive out patients awaiting contrast were block r and omized into one of eight groups based on age , sex , and previous contrast exposure . For each group , half were given their consent form at least 24 hours prior , and the other half at the time of their procedure . All patients were tested at the time of their procedure to evaluate knowledge retention . RESULTS Comparison between the two study groups showed no overall statistically significant differences either in knowledge ( experimental group 4.7 + /- 1.32 versus 4.38 + /- 1.30 control group ) or level of satisfaction . Additionally , individuals experienced with contrast failed to outperform those who had never previously been given contrast . There is no significant difference in the performance between the two sexes regardless of group . CONCLUSIONS The providing of information 24 to 72 hours in advance of an invasive procedure does not have a beneficial effect over just providing the same information at the time of the study
We have identified efforts by research ers to investigate interventions which seek to improve information delivery and consideration of information to enhance  informed consent .
The interventions used consistently improve patient knowledge , an important prerequisite for informed consent .
This is encouraging and these measures could be widely employed although we are not able to say with confidence which types of interventions are preferable .
Our results should be interpreted with caution due to the high levels of heterogeneity associated with many of the main analyses although we believe there is broad evidence of beneficial outcomes for patients with the pragmatic application of interventions .
BACKGROUND Achieving informed consent is a core clinical procedure and is required before any surgical or invasive procedure is undertaken .
However , it is a complex process which requires patients be provided with information which they can underst and and retain , opportunity to consider their options , and to be able to express their opinions and ask questions .
There is evidence that at present some patients undergo procedures without informed consent being achieved .
OBJECTIVES To assess the effects on patients , clinicians and the healthcare system of interventions to promote informed consent for patients undergoing surgical and other invasive healthcare treatments and procedures .
AUTHORS ' CONCLUSIONS Informed consent is an important ethical and practical part of patient care .