Trip Database Blog

Two pieces of wiki news:

1) Dean Giustini has started the UBC HealthLib-Wiki (A Knowledge-Base for Health Librarians):

The idea is to provide a forum for best practice for health librarians, and other information professionals around the world…….We believe this open-model will more accurately reflect the “wisdom of the field” and bring significant value to the wiki’s knowledge-base.

2) Ganfyd, the clinical wiki, is still going strong and an amazing amount of content is now in there. Due to the distractions of getting the TRIP Database re-designed and free I’ve neglected my input. However, as well as being able to contribute I have, at last, found a way of importing data from ganfyd into TRIP. It’s not a hugely robust way but it should end up covering the vast majority of the content fairly quickly.

We’ve had an awful lot of e-mails thanking us for moving to free-access. One of the first (within 3 hours) was from a UK health librarian:

“This is good news! It’s already helped me to find a piece of guidance I hadn’t found by any other route.”

Protocol for the Quick Clinical study: a randomised controlled trial to assess the impact of an online evidence retrieval system on decision-making in general practice . Although I feel more research is needed in this area I’m not hugely convinced about the meaningfulness of any results from this trial. One can predict that those that used ‘Quick Clinical’ will help change clinician behaviour and support clinical decisions. But, more importantly, it won’t check on patient outcomes.

If we want doctors, nurses etc to incorporate ‘evidence’ into their practice we need them to use it routinely, make it very easy to use and supply ‘nuggets of evidence’. I really don’t think that is controversial.

On an unrelated note and following on from earlier blog-entries about USA about citywide wireless access, Norwich, UK is doing the same (click here for BBC News story). I’m still convinced that wireless access to the internet will be widespread (at least in the ‘developed’ nations) in the not too distant future.

The re-indexed material was added at 9am this morning and so far things are working well with no obvious problems.

Well the site is now live, which is a relief. Alas, not all the content decided to join us! Therefore, we’re currently re-indexing things. As it stands all the titles, URLs, publication information are there. However, we’re missing a small (but significant) proportion of text from the body of some publications.

Still it should all be there in time for our scheduled launch date of tomorrow!

We set a target of making TRIP free-access at the start of the year. By March/April the decision had been made. We then needed to give 6 months notice to our distributor (Update-Software) and here we are. Three-months before the end of the year with free-access and a radical re-design of the site.

In previous blog entries (as part of the ‘Countdown to free-access’ series) I have highlighted new features. The last post, in this series, is to highlight a simple fact – we will be free-access. There will be no subscription charges to search TRIP. Clinicians (and non-clinicians) will be able to go to www.tripdatabase.com and have free use of the TRIP Database.

It’s free!

New search algorithm

The biggest change to the new, free TRIP is the search algorithm. For the last 5+ years the TRIP search has been dominated by the distinction between a ‘title’ and ‘title and text’ search. This allowed for great searching. The rational being that if the document was about asthma it would be mentioned in the title and the vast majority of searches were on title only. This presents a couple of principle problems.

Firstly, if you do a search on asthma you would generate (even as a title search) a large number of results. This makes the task of identifying relevant material difficult. Why? Because users rarely want information about asthma. They may be interested in asthma and steroids, or asthma and allergies – rarely just asthma. This over-simplified search was highlighted in Professor Paul Glasziou’s evaluation which showed most people just searched for the actual disease. So if you wanted to look at asthma and steroids the best search would be:

1) Title search for asthma
2) Title and text search for steroids
3) Combine the results
4) Click on a results categories to see any results

So 4 steps to see any results – in hindsight that seems ludicrous!

Secondly, Google – well it’s a nice problem. But most people who use TRIP will invariably be more familiar with Google. So they’re used to adding any number of terms and letting Google quickly return results, which it does very skilfully! Also Google tends to be searched using multiple search terms. The average number of search terms used per search is gradually increasing over time, surely a reflection that users are becoming more sophisticated/discerning. We’re hoping this increased use of terms will be reflected in the new TRIP.

So, the challenge was to try and mimic the Google search interface (i.e. no ‘title’, ‘title and text’ distinction) yet still return good results. To a large extent we’ve produced a system that works well. We’re not saying it’s perfect and our role, from now, is to continue to improve on the search algorithm. The actual algorithm is based on three main variables:

1) Publication date – more recent articles score more highly than older documents
2) Publication – each publication (e.g. Cochrane, Bandolier etc) are given a score based on their rigour and clinical usefulness. This is based on our experience of answering 5,000+ clinical questions – we tend to know which publications answer clinical questions more than others. Our scores reflect this experience.
3) Textual analysis. The main issue is where the search terms appear. If you do a search for asthma and steroids if a document has both terms in the title it gets the highest score, if one term is in the title a lesser score while if the terms only appear in the text it scores lowest. Another, lesser, component is term density. If asthma is mentioned 50 times in a document it scores more highly than a document which only mentions it once.

The above variables are then combined to produce the results.

Given the nature of the search system good results for one person might be bad results to another and in testing we occasionally get results which surprise us. However, on the whole we are getting excellent results, this is our experience and from feedback from our external testers. But, we’ll continue to refine and enhance the search – feedback welcome!

Drug Box

One of the most frequent question types we get at our various clinical question answering services relate to drug information e.g. does this drug interact with that drug, what are the impliactions for pregnanct women etc. For this reason we have created the Drug Box. To start with we have used the most frequently prescribed drugs (around 200 of them). Anyone searching for information on the drug will be presented with the usual search results. However, where the sponsored links usually are, will be the Drug Box, see below:

We’re very pleased with this new service and new drugs will be added over the next few weeks and months.

Linking to TRIP

Moving to free-access opens up all sorts of opportunities to ‘distribute’ TRIP. We’ve got a number of ways:

Incorporation of search box into third-party websites. We’ll be supplying HTML for webmasters to incorporate a TRIP searchbox into their own web-pages. We had this feature previously (before we went subscription-based) and this proved very popular.

Web-services. This allows third-party resource to search TRIP via a SOAP interface, the results are returned in an XML format allowing the third-party resource to seamlessly link the TRIP results into their own application.

URL searches. Allow webmasters to add a specific URL with the search term embedded e.g. www.tripdatabase.com/…….criteria=measles will result (if someone clicks on the URL) in an automatic search of TRIP for measles.