In the rich, evolving EBPH literature, two major themes are apparent.
The first step in the EBPH process is "problem assessment," in which public health concerns of interest are identified and surveillance and survey data are reviewed to evaluate associated disease burdens on a population basis.
The issue of what criteria should be used to evaluate the evidence is perhaps where there is the least consensus in the EBPH community, an issue to which we turn in greater depth below.
A second major theme in recent EBPH literature is that EBPH requires a different approach to evaluation of evidence than EBM, in that RCTs are placed at the top of the evidence hierarchy.
In general, EBPH practitioners have emphasized the public health need for a wider range of evidence types and suggest a less hierarchical approach to study methods (Brownson et al.
Exploring these issues necessitates a wider range of research questions that speak more directly to the contextual specificity of the EBPH process in particular settings (Rychetnik et al.
In summary, it is clear that EBPH is now an important part of public health and that there is a generally accepted approach to the process.
By its nature, EBPH tends to be applied to established health concerns with a significant evidence base, bounded impacts that are apparent historically and in present time, and for which administrative responses have been at least partially established.
Despite study design flaws, particularly the lack of randomization, an EBPH approach would suggest that the best available evidence is in favour of preschool screening for amblyopia.
An EBPH approach would suggest that the best available evidence favours universal screening for amblyopia.
In summary, we have revisited the evidence on amblyopia screening with an EBPH perspective in order to set the grounds for a discussion on whether Public Health's involvement in screening in Canada is justified.