Update on CST work by me (Chris Evans)

Of the three of us, I’m responsible for the web site, most Email that come via the site, and all the translation work. Since our post on 7/7/16 I was very caught up in finishing my clinical post (permanently) at the end of July and then setting off on a trip of a lifetime: trying to cycle from London to Stantiago de Compostela in Spain.  I had to sort out some nasty problems with the web site (WordPress is mostly great but some plugins we have had to use really aren’t) and do a number of pressing bits of translation related work.  On my trip, having time, energy (it’s hard work cycling in the heat for all it’s a wonderful privilege!) and, above all, working IT/wifi/internet has been a nightmare and I have given first priority with that time to the pilgrimage site (www.psyctc.org/pelerinage2016/)  

I am very sorry, but I am simply not going to be able to handle more than tiny CORE related things until my trip is over and I’m back at work: the first week of October. However, one reason for finally stopping clinical work was to make more time for CORE so I hope I will be able to make real inroads into the backlog when I do return.  Apologies for now … but do have a look at the pilgrimage web site as it may amuse you and I do touch on important CORE and healthcare issues. I always hoped to have time to think about them properly like this.  

CST, CORE and the UK “Brexit” vote

All three of us as CST trustees are deeply disappointed in the outcome of the referendum.  As a part of a collective recovery from the vote, it seems important to make a statement about our position.  CORE is tiny in terms of the impacts of “Brexit” on the UK and the EU, and the horrible and uncertain impacts for so many EU nationals currently in the UK and the students here or about to come here.  However, we believe it may help if many tiny things come together to underline that the vote was marginal, that many who voted to leave are regretting it, and that it was NOT just a vote of separatism and petty nationalism but also a vote of dissatisfaction with current political power structures (in the UK and in the EU).

Little and big things are needed to try to minimise the negative impacts of “Brexit” so we wanted to put the following points on record.

  • CORE’s origins are in the UK and UK English versions of the instruments were the prototypes.  However, the CORE project was always inclusive and we always sought to achieve first rate translations provided that translations were culturally appropriate.
  • Full European availability of the CORE instruments was always a CORE aspiration and we are near to having good translations into all official EU languages.
  • Our copyleft strategy and commitment to translations has always been part of that inclusive and internationalist stance.
  • Despite the narrow, divisive and painful “Brexit” vote CST will remain committed to usage and availability within the whole of Europe and more widely.
  • We cannot now lead bids for EU funding but we will continue to support anyone wishing to make such bids and will continue to build links with all EU countries.

Chris Evans (on behalf of CST)

What’s in a name (2): domains, scales, scores, factors & dimensions

The original commissioning specification for the CORE system required that the items in the measure covered domains of wellbeing (or “well being”, or “well-being”: there’s another naming issue!), problems/symptoms, functioning and risk.  The questions were supposed, where possible to include intrapsychic ones and interpersonal ones and functioning was to cover both more personal/intimate and more social functioning and risk should cover intrapunitive and extrapunitive risk, i.e. risk to self and risk to others.  We liked this framework and noted that the first three domains had some links to the phase model of change in therapy which suggests that well-being change comes first, then symptom/problem improvement, then functioning improvement (Howard, Lueger, Maling & Martinovich (1993) A phase model of psychotherapy outcome: causal mediation of change. J Consult Clin Psychol. 61(4):678-85).

We thought the commission specification was right that these were fairly conceptually distinct domains of experience that should be covered by a measure of change in therapy and that was supported by extensive surveys of therapists/practitioners, managers, commissioners (“purchasers” in the jargon of the time) and end users and lay people and we thought we should say which items we saw as belonging most strongly to which domains and offer the opportunity to study scores, and changes in scores, on each domain.  However, we never imagined that these would form clear “factors” or principal components in cross-sectional psychometric studies nor that the chronological relationships between them over time in cohorts or even within a single person in therapy would be neat.  If you feel lousy (low wellbeing) it’s likely that you will have or develop problems and even symptoms, and vice versa.  Similarly, struggling to function well either in personal interactions and/or at work or in caring duties will dent a sense of wellbeing and lead to problems: these simply aren’t independent factors or dimensions. 

With the advantage of hindsight it’s easy to see that we should have been clearer about that.   We tried to use the terms “domains” and “domain scores” in preference to “factors”, “dimensions”, “scales” but slipped from time to time.  We thought we were sufficiently explicit about our use of exploratory factor analysis being exactly that: exploratory, and mainly to check that there was a large main factor and a good collection of smaller factors.  We were unsurprised in our early work (Evans, Connell, Barkham, Margison, McGrath, Mellor-Clark & Audin (2002) Towards a standardised brief outcome measure: psychometric properties and utility of the CORE-OM. British Journal of Psychiatry, 180, 51–60) to find a structure that didn’t reflect the domains but which seemed to some extent to separate positively cued from negatively cued items and to separate the risk items from the other items.  We have never expected that this structure would replicate strongly in different cultures and samples and we only used confirmatory factor analysis to show just how poor the fit to a simple factor structure (Lyne, Barrett, Evans & Barkham (2006) Dimensions of variation on the CORE-OM. British Journal of Clinical Psychology, 45, 185–203).  That paper was intended to be a definitive statement about the expected psychometric structure, at least in British clinical samples.  Here’s the statement from the abstract:

The CORE-OM has a complex factor structure and may be best scored as 2 scales for risk and psychological distress. The distinct measurement of psychological problems and functioning is problematic, partly because many patients receiving out-patient psychological therapies and counselling services function relatively well in comparison with patients receiving general psychiatric services. In addition, a clear distinction between self-report scales for these variables is overshadowed by their common variance with a general factor for psychological distress.

And the end of the discussion:

These considerations with respect to the CORE-OM domains are of importance for future research and scale development, but the utility of CORE-OM has already been demonstrated as a widely used benchmarking measure and reliable indicator of change in psychotherapy research and practice. The scoring method that has proved most
useful in this regard is that in which all 28 non-risk items are scored as one scale and the
risk items as the other. This research confirms that the scale quality of CORE-OM when
scored in this way is satisfactory.

So some suggestions/pleas:

  1. by all means report change on specific domain scores if they are pertinent for the work that went on with the client/patient but don’t imply that the specific scores are well defined factor analytic scales;
  2. the risk and non-risk items are sufficiently distinct in cross-sectional psychometric studies that it may be wise to report the non-risk and risk scores as well as the total scores in almost any study;
  3. if you possibly can, talk about the scores from the CORE-OM and CORE-SF/A and SF/B as “domain scores” not “dimensions” or “factors”.

What’s in a name (1): scoring CORE measures

We may have caused a bit of confusion by introducing the term “Clinical score”.  Perhaps it’s not on the scale of the Capulet/Montague name tragedy (Shakespeare, 1591-1995?) but it may be worth explaining the scoring here as I do see mistakes and do get asked about this.


We started out scoring using the mean of the items and recommending pro-rating if not more than 10% of items were missing, i.e. using the mean of the remaining items.  That meant you could get a pro-rated mean overall score for the CORE-OM if as many as three items were missing, for the “non-risk” score if two of the non-risk items were missing, for the function and problems scores if one of their items was missing, and you couldn’t pro-rate if any items were missing for the well-being or risk scores.  You could get overall scores for the CORE-SF/A, CORE-SF/B if one of their items was missing (but not for domain scores as any missing item there means more than 10% of the items are missing).  Similarly, you could use a pro-rated score for the GP-CORE, the LD-CORE, the YP-CORE and the CORE-10 if one item was missing but pro-rating the CORE-5 was clearly impossible. 

All those scores had to lie between 0 and 4 by definition but they could be awkward looking numbers like 0.84 and over the early years we got feedback that many clinicians and managers didn’t like these “less than one and fractional” scores. 

“Clinical Scores”

With mixed feelings in the team, the idea of “Clinical Scores” came in: the item mean as above, but multiplied by 10 to get a score that in clinical samples would pretty much always be a x.y sort of number with x >= 1 and scores ranging between 0 and 40. The same rules about pro-rating were retained.  This “x10 = Clinical Score” gives that rather easy scoring for a complete CORE-10 or complete YP-CORE that the “Clinical Score” is just the sum of the 10 items completed (but if one item is omitted you still have to find the mean of the nine completed items and multiply that by 10).   For a completed  CORE-5 the route to the “Clinical Score” is almost equally easy: the Clinical Score is twice (2x) the sum of the five items’ scores.

We sometimes see people reporting the sum of the items: please don’t do that, we’ve never recommended that anywhere.  We also see people not saying explicitly that they’re using the original “mean item score” or the “Clinical Score”, please do say which you used even if it seems very obvious.  Finally, we encourage people always to be explicit about having used pro-rating (if you have) and to be explicit about numbers of incomplete questionnaires and numbers of items missed. This all maximise comparability of reports.  Non-comparable scoring may not be as lethal as Mantua family feud was to Romeo, Juliet and Mercutio, but it’s definitely to be avoided!


Shakespeare, W. (1591-1595, exact date uncertain) “Romeo and Juliet” available in many versions as the peer-reviewed format hadn’t been invented: quarto 1, quarto 2, first folio and later versions.  However, the fatal name issue is consistent in all.

Putting a CORE measure into software

Since the first of January (2015) anyone can put any CORE measure into software under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International licence.  Previously, we had restricted this permission just to people using the measure in software just for a research project and otherwise only to CORE Information Management Systems (CORE IMS) and people sublicensing through them.  See our joint statement for more information.

The Creative Commons licence puts two restrictions on anyone putting the measures in software: they must acknowledge the origins of the measure and they mustn’t change the measures.  This is in line with the situation for paper reproduction of the measures which has always been on these “copyleft” terms.  However, both the acknowledgement and the “no changes” were easy for reproduction on paper: just print out the PDF and the acknowledgement is there in the copyright statement at the foot of every page and any printing to any sensible printer from PDF guaranteed no meaningful changes.

The situation is not so clear when a measure is put into software and we’re gaining experience, and remembering some of the early learning we did with CIMS some years back.

Acknowledgement is fairly easy: if the line “Copyright to CST: http://www.coresystemtrust.org.uk/copyright.pdf” that is in the PDF versions is there, and if ideally the link is clickable and opens to that URL, then you have done the minimum we ask by way of acknowledgement.

No changes is  a bit more complicated as obviously the formatting is pretty well bound to change depending on the device on which the text appears.  Where the intention is for end users (patients, clients, service users, research or survey participants) to use the measure in the software the following must be true:

  1. The introduction (“IMPORTANT – PLEASE READ THIS FIRST This form has 34 statements about …” should be unchanged in content but the line “Please use a dark pen (not pencil) and tick clearly within the boxes.” can be replaced with whatever is sensible to tell the user how to fill in the items.
  2. The time frame (“Over the last week”) must come before the items and at the head of each block of items.  If the items are presented oen at a time, this must be there with each item.  We recommend if the items are presented sequentially that the system offer an option to see the introductory instructions (#1 above) with every page.
  3. The response anchors (“Not at all” to “Most or all the time”) must be unchanged and against each response option.
  4. Clearly the “Please turn over” instruction from the CORE-OM can be dropped but something similar should be used to try to ensure that people do page through all the items.
  5. The system does not have to calculate the overall score and present it to the end user.  If it does, it must do so correctly, see #6.
  6. Scoring is simple and the “clinical scoring” of 10x the the mean item score is used for all measures.  Perhaps counterintuitively the “well being” domain score is scored in the same direction as the other domains, i.e. higher scores indicate lower well being.  Prorating can be applied for any score provided that fewer than 10% of the items on the score have been omitted.  Clearly for scores with fewer than ten items this means that no prorating of missing items is supported.  It is the responsibility of whoever is putting the measure into software to ensure that the right items are mapped to the right scores, that “positively cued” items (e.g. “I have been happy with the things I have done” have their scores included correctly (i.e. scoring 4,3,2,1,0 rather than 0,1,2,3,4 for the “problem cued” items) and that scoring is correct.
  7. We are happy to review any implementation with you if we have time for this. Currently, if this is not particularly urgent, we do not charge for this but we may have to change that if the work load becomes significant.
  8. We could provide sample data to be entered for all the measures that could be used to check scoring and can help with that but that is a significant piece of work for which we would have to charge and sample data are under development currently.  The responsibilty will still remain with whoever programs the scoring.

This is all work in development and we will turn this into an FAQ as experience develops but experience so far has been that complying with the licence conditions and checking that is not onerous for the programmers/designers nor for us to check.

Do get in touch with us if you would like us to work with you on this or if you are confident you have done it fine and just want us to know you are making the measures available with computer support.

Best wishes,

Chris Evans (for CST)

Happy New Year!

Just a quick post to say that a very incomplete site, but one that contains the vital information about the change in licensing and the bare bones of all that will come, goes live, as planned, today.  Best wishes to all,


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