Evidence based medicine: looking forward and building on what we have learnt

Who contextualises clinical epidemiological evidence? A political analysis of the problem of evidence-based medicine in the layered Dutch healthcare system

We critically examine the discussion on the role of evidence-based medicine (EBM) in healthcare governance. We take the institutionally layered Dutch healthcare system as our case study. Here, different actors are involved in the regulation, provision and financing of healthcare services. Over the last decades, these actors have related to EBM to inform their actor specific roles. At the same time, EBM has increasingly been problematised. To better understand this problematisation, we organised focus groups and interviews. We noticed that particularly EBM's reductionist epistemology and its uncritical use by 'professional others' are considered problematic. However, our analysis also reveals that something else seems to be at stake. In fact, all the actors involved underwrite EBM's reductionist epistemology and emphasise that evidence should be contextualised. They however do so in different ways and with different contexts in mind. Moreover, the ways in which some actors contextualise evidence has consequences for the ways in which others can do the same. We therefore emphasise that behind EBM's scientific problematisation lurks a political issue. A dispute over who should contextualise evidence how, in a layered healthcare system with interdependent actors that cater to both individual patients and the public. We urge public administration scholars and policymakers to open-up the political confrontation between healthcare actors and their sometimes irreconcilable, yet evidence-informed perspectives.

Cataract surgery and age-related macular degeneration. An evidence-based update

Purpose

Age‐related macular degeneration (AMD) and cataract often coexist in patients and concerns that cataract surgery is associated with an increased risk of incidence or progression of existing AMD has been raised. This systematic review and meta‐analysis is focused on presenting the evidence concerning progression of AMD in patients undergoing cataract surgery.

Methods

We performed a systematic literature search in the PubMed, Medline, Cochrane Library and CINAHL databases. Two randomized trials and two case–control trials were identified. Quality of the studies was assessed using the Cochrane risk of bias tool, data were extracted, and meta‐analyses were performed. Quality of the available evidence was evaluated using the GRADE system.

Results

We found that visual acuity at 6–12 months follow‐up was significantly better (6.5–7.5 letters) in eyes that had undergone cataract surgery than in unoperated eyes, but the included number of subjects was small, and hence, the quality of evidence was downgraded to moderate. We did not find an increased risk of progression to exudative AMD 6–12 months after cataract surgery [RR 3.21 (0.14–75.68)], but the included number of subjects was small, and thus, the quality of the evidence was moderate.

Conclusion

Cataract surgery increases visual acuity without an increased risk of progression to exudative AMD, but further research with longer follow‐up is encouraged.