What do you mean? As I understand it, LexisNexis is just a database of legal articles. PubMed is a similar database of medical articles. PM lacks the full text of the articles and even the bibliographies, but it seems to me adequate for this purpose. The difference seems to me to be a matter of culture, of making a point of doing the search. Also, the hierarchical nature of law makes it easy to tell if one opinion trumps another.
Math Reviews is a database of journal articles that includes complete bibliographies for the recent articles. I suppose that must require a deal with the journals, but I wonder why PubMed didn't make the same deal? Google Scholar is an automatically generated citation database.
From The Atlantic's Lies, Damned Lies and Medical Science:
Here's a suggested solution to the problem of refuted research still being cited. Have some respected agency maintain an archive of studies that have failed to replicate or that have otherwise been found lacking. Once such an archive existed, medical journals could adopt a policy of checking all citations in a proposed article against the archive, rejecting submissions that tried to cite refuted research as valid. This might also alleviate the problem of people not doing replications because replications don't get many cites. Once such an archive was established, getting your results there might become quite prestigious.
The one major problem that I can see with this proposal is that it's not always obvious when a study should be considered refuted. But even erring on the side of only including firmly refuted studies should be much better than nothing at all.
Such a fix seems obvious and simple to me, and while maintaining the archive and keeping it up to date would be expensive, it should be easily affordable for an organization such as a major university or the NIH. Similar archives could also be used for fields other than medicine. Is there some reason that I'm missing for why this isn't done?