Here’s the most recent version of your question about kidney disease:
There’s a problem with asking for the “best way to manage” any condition.
As a clinician or a policy maker, you might be looking for the ideal management option, but “ideal” could include: what works best, what the patient prefers, what’s easiest to use, what’s most cost-effective, what’s safest… the possibilities go on and on.
Most systematic reviews* aren’t designed to determine what is “best”. Instead, they seek to compare two or more treatment options.
*There are some systematic reviews that DO compare the full range, or network of treatment options. That type of systematic review requires what is called “network meta-analysis.”
Also, it’s important to remember that systematic reviews are designed to summarize evidence, not make practice or policy recommendations. That’s the role of policy makers- to take what a systematic review uncovers and use those findings to make a decision.