Evidence in palliative care research: how should it be gathered?

In evaluating evidence for clinical care, study designs are graded according to their potential to eliminate bias, and the most robust evidence is considered to come from randomised controlled trials (RCTs). However, the reliance on study design as the main criterion for credibility of evidence has its critics,4 as does this view of what constitutes the 'best' evidence. In public health in particular, there is debate about the primacy of the RCT for evaluating interventions and about the tendency to downgrade the contribution of observational studies. More recently, this debate has moved to emerging research areas, such as palliative care. This discipline urgently requires a wider evidence base, but acquiring this evidence presents particular problems.