Limitations in the research
Most studies of nurse–doctor substitution have included only
small numbers of nurses, and very few have considered the
potential for practitioner-related variation in outcomes. Patient
samples have generally been too small to detect rare, but potentially
serious, health outcomes such as missed diagnoses. An added
concern is that studies to show the comparability of care by nurses
and doctors need to be designed to have the power to assess
equivalence, not difference, in outcomes. This has been done in
only one study.8 The evidence base is further limited by the narrow
range of nursing roles that have been rigorously evaluated. Nurses
in the UK manage a more diverse range of patient problems than is
currently represented in the research literature. As noted above,
the potential for cost savings is context dependent and therefore
needs to be evaluated on a case-by-case basis.