How do we acquire high-level evidence in urology? A 30 year perspective

Like many other young residents, I started my research work by studying patient files to be able to present a retrospective case series of patients treated in our department. If you were ambitious you could present your results as a lecture or poster at a conference and later publish the results [1]. That kind of work has very limited prospects of being published today because of the well-known shortcomings of such analyses, including selection bias [2].

In the second step of my research career, I was involved in randomized prospective clinical trials, or randomized controlled trials (RCTs). We were very excited about the possibility of being able to report high-level evidence. Unfortunately, it has become increasingly difficult to carry out randomized trials because of increasing administrative demands and economic constraints. It has also become evident that these trials are handicapped by selection, and thus systemic reviews and meta-analysis have come into fashion. During the past decade, the number of articles in PubMed resulting from the search term “meta-analyses” has soared from 300 to more than 11,000. Today, we know that these analyses can also be biased and as an editor I feel that they have lost some of their attraction owing to the overwhelming influx [3].

In this issue, I am happy to present results from five Nordic urological cancer quality registries. The basis for these is the regular cancer registries that started more than half a century ago. The first of the presented registries started in 1980 and the last in 2014. Two are multinational and three are Swedish only. The advantage of these compared to RCTs is less selection bias, but confounding is still possible owing to unregistered clinical characteristics and limited monitoring.

An interesting new successful development has been the combination of methods by including a randomization module in a quality registry. This could potentially lead “to fast inclusion of large patient numbers, focus on hard endpoints and complete follow-up and at a fraction of the costs of today’s randomized clinical trials” [4]. The use of this methodology in urology is eagerly awaited, but I expect that in the future we will once more learn that every new methodology has its drawbacks.