You might start with implementing the changes on one or two cases first, and then you can ASSESS what might be changing. For instance, you might consider borrowing or leasing a particular piece of equipment if you think it might be required, so that you can evaluate how useful the equipment might be to your practice before you make a large financial investment.
Or, in your search for evidence, you may discover that there is anecdotal evidence about potentially efficacious treatments that some colleagues have heard of, but there is still no study data to support this efficacy. You might decide to follow up these leads at a later time, as you know that some caution should be applied in these situations where only circumstantial evidence exists.
Or, depending on what changes you are considering, you may first decide to talk to your client about the new approach or treatment and the possible side-effects that might result. This approach should be considered on the basis of good ethical practice and local governing body guidelines.
The choice is up to you, but once you apply your evidence, you will also want to ASSESS how that application has gone!