Trip Database Blog

Liberating the literature


July 2018

PICO search – time for improvement(s)? If so, how?

Our PICO search is really popular but it’s not changed since it was introduced years ago.  For those unfamiliar with it, this is what it looks like:

Our search works on a contingency search basis.  So, assuming the user enters 4 search terms (a P, I, C and O) we do an initial search looking for the terms in the title only. If there aren’t many results we repeat with P, I and C as a title search and O as title and text.  If there are still too few, we do P and I as title and C and O as title and text etc.

It seems to work well, but I’m sure it could be improved especially given our work with the KConnect project – where we specifically annotate articles with the PICO elements (albeit only the RCTs and systematic reviews).

But as we look to overhaul it we need your help….

Do you use the PICO search?  Is it perfect?  If not, how might it be improved?



Understanding (bad) search results

Given the recent interest in guidelines and Trip we’ve had a number of new conversations with users from the USA.  I’ll reproduce (well, slightly edited) one below as I think it’s broadly useful for others to understand a fairly common search problem. In this case the person highlighted how frustrating searching for guidelines can be, so here’s my response:


Firstly, as previously mentioned, guidelines are particularly problematic as they typically long and cover a broad range of topics. This creates two different problems – missing them and noise!

Missing them

So, you might have a guideline ‘The diagnosis and management of hypertension‘ which covers loads of areas. It might mention gestational hypertension as a chapter, but nothing more. If you searched for gestational hypertension this guideline would not feature highly as gestational is not mentioned in the title (our system favours matches in the title). So, it appears low down in the search results (even though that chapter might be the best result there is for the user). This is frustrating and we have a few things we’re going to try in the near future to improve this! But, your problem is more the noise…


Take one of your example search safety mechanical ventilation, when you search on the main Trip (so no refinement) you get the following results:

I’ve highlighted the scores – which relate to how relevant the document is to the search terms (BTW only I get to see those scores). But when you refine to USA Guidelines it gets noisy:

You’ll see, from result 3 the relevancy goes right down. In fact, only 2 (of 85 USA guidelines we return) look reasonable.

This comes back to the size of guidelines. They’re long and invariably the search terms appear within them – but they might mention safety, mechanical and ventilation all in different contexts. But as they include the terms they are counted as ‘hits’ and returned. Search can be stupid!!

The thing that we think we’ll introduce is a relevancy cut-off so we could say only return documents with a relevancy score above 0.1, 0.2 (we’d need to test) but allow users to ‘see ALL documents’ – if they want the noise!

Latest and greatest

This is an often overlooked feature of Trip, so it’s about time I highlighted it.

Latest and greatest takes a topic and looks at the latest evidence for the topic and also the ‘greatest’ – by that, the articles that have been clicked on most for the last 12 months.  A list of topics can be found here but you can access the latest and greatest for any topic via the link at the top of any particular search, for example:

We particularly like the ‘greatest’ side of the feature as it allows uses to easily see the articles deemed most useful/interesting for a given topic.  A bit like a topic-based clinical zeitgeist!

Free and easy to use.

Some examples below:


For the full list, click here.

Multiple sclerosis

For the full list, click here.


For the full list, click here.

The post-NGC landscape, a sample of US guidelines added to Trip this month

I’ve written about our attempts to mitigate the loss of the National Guideline Clearinghouse (even producing a ‘conversion’ how to use Trip guide).  But below are a sample of the new guidelines, added this month, to Trip:

As mentioned, the above is a sample, a modest sample 🙂

Searching for guidelines post-NGC

This post is to help National Guideline Clearinghouse (NGC) users navigate Trip to find the guidelines they need.

Firstly, Trip links to over 3,500 guidelines from the USA (and over 10,000 guidelines in total).  The NGC used to provide summaries to less than half this amount (for a variety of reasons). But Trip is much more than guidelines, we includes a broad range of resources arranged around the evidence hierarchy – as you use Trip you’ll come to appreciate this.

Another thing to consider is Trip’s a very small organisation with a budget a fraction of the NGC and therefore we are not able to mimic all of the sophisticated search refinements of NGC’s.  We are funded via a freemium business model (to understand the differences see the chart here).  Note the guidelines are provided for free but please consider subscribing to help support our efforts (individual and organisational subscriptions are available).

Anyway enough preamble, to search for guidelines navigate to Trip and you’ll see this screen:

I suspect it’s superfluous but I’ve added a big arrow showing where you add the search terms.  Once you’ve searched you go to the results page:

This is the results for all our content so you may want to refine the search for guidelines or USA guidelines, this is easy:

The refine feature is on the right-hand side of the results page. This allows you to refine results by any evidence type, but the two highlighted are for all guidelines and USA guidelines.  If you click on the USA guidelines the results are restricted to just those:



You can further refine by year (see towards the bottom of the refine area on the results page).  Trip Pro also allows advanced search and refine by clinical area.

For further information on using Trip we have produced a selection of ‘how to’ videos and you may find the ‘Tour’ interesting:

Any further questions, just send them my way:


PubMed: Cited by feature

I’d not noticed the cited by N systematic reviews before in PubMed:

I’m thinking that might be useful!


Trip Overviews of Evidence, more examples

A further list of automated reviews for you to browse:

Question answering – the next step(s) for Trip

As well as improvements to our automated review system we’re planning more improvements to the site and it’ll focus on getting back to our roots – clinical Q&A.  Trip was born out of a need to help support a formal, manual, clinical question answering service (called ATTRACT) and is still the main reason people use Trip.

We’re looking to build on lots of separate features we already have in Trip:

But we hope to bring a number of other techniques ranging from machine learning to community support.

We can’t wait…

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