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 .
Informed consent: how much information is enough?
BACKGROUND Recent judicial decisions involving informed consent have led to some medical practitioners altering the way they obtain consent . The aim of this study was to determine the degree to which patients understood the risks associated with a surgical procedure after giving routine consent and whether providing additional detailed verbal and /or written information improved their underst and ing . It was further determined whether the provision of more extensive information altered patients ' anxiety levels . METHODS Patients undergoing femoral popliteal bypass or carotid surgery were r and omized to obtain either routine consent only or routine consent with verbal or written or verbal and written consent . Patients undertook a pre-operative risk and complication question naire , a pre- and postoperative anxiety and depression evaluation and a follow-up question naire 6 weeks after discharge . RESULTS Thirty-two patients were included in the trial . The comprehension question naire result ed in a correct percentage response of 48 % for the routine information only , 59 % with added verbal information , 59 % with added written information and 55 % with added written and verbal information . Twenty-five per cent of patients stated that they had a poor underst and ing of the risks and complications of the procedure . CONCLUSIONS Additional written or verbal information did not improve a patient 's underst and ing of risks and complications of the procedure . It also did not improve patients ' perceived underst and ing of the operation or its complications . Patients ' anxiety levels were unaltered by the increase in the information they were given . The information provided to patients should be simple , easy to underst and and list any possible major complications to enable the patient to determine whether to undergo or decline a procedure
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 .