I recently ran a literature searching tutorial for MSc students undertaking a systematic review as a piece of course work. I'd seen many of them individually, as had colleagues, and so offered the tutorial to make sure we had not missed anyone. Of course, those who turned up had already been to see us individually! The keen ones take up all the offers and the challenge is to reach those who are not so keen, don't feel they can ask for help, or think they are ok.
I had it mind to talk about general things, but began by asking if they had any specific questions. This was one: if you find a conference abstract, and you want to use the data in your analysis, and the data in the abstract is not detailed enough, where do you go to get the detailed data?
I said that you would have to look for an article about the same study. But how easy is this article to find? Presumably it has the same authors and title, but maybe not. If the abstract is of a trial, and the trial is recorded in a registry, the registry entry may well record the article.
The students also had an example of the same trial being written up in two articles. Ben Goldacre's work records that many trials never make it into any sort of article. Both these things are, it seems to me, rather naughty. Perhaps it is more difficult to find the associated article than I think.
I had a quick look in Web of Science Core Collection for conference abstracts from 2007 about antimicrobial resistance. I chose three (which I know is a tiny and unrepresentative sample). I then looked in PubMed (a proper look would have course been in WoSCC as well, which I shall endeavour to do before too long) for the first two authors, or authors and a title word if that found too many. One found something very similar which on closer inspection was from 2005! The other two did not seem to appear. Perhaps they were never written up in full articles. If not, why not? Some subject areas in non biomedical science assign great importance to abstracts and maybe things get no further. Is antimicrobial resistance an area like that within biomedical science and was there no need to write it up? If so, then this means it really is important to search for abstracts and not just articles. Or were the studies not quite up to it?
Of course, a fuller and more systematic investigation is needed! There is a bit more elsewhere in another post.
If you can't find an article that has the detail you need, and there is not enough detail in the conference abstract, what then? Is this one of those situations where you contact the authors for more information, as the textbooks about systematic reviewing say? Interestingly, the students had tried this (not sure if it was for data from a study that had only appeared as an abstract, or not) and had received the reply that the author(s) was/were too busy to help. Perhaps if you are not a student, but a postdoctoral researcher, you have more luck.
Another quick look in WoSCC turned up two papers by the same team, Yunal Dundar and colleagues from the University of Liverpool, from 2006, one about searching for abstracts and the other comparing data from abstracts and subsequent full articles . (The links are via DOI and you will need a subscription to read them).
Both are in the context of health technology assessments and I need to read both before I meet people in the same situation as my MSc students!