The CORE-OM and the h-index

The CORE-OM was the yield from a 3-year grant from the UK Mental Health Foundation, which started in 1995 and resulted in the launch of the CORE-OM and associated system in 1998. One question with all such developments is: what has been its impact?

As those working in university settings will know, one index of the impact of an individual’s research is their h-index. In 2005, physicist Jorge E. Hirsch developed a simple premise to quantify the scientific output of an individual researcher. The value of h is equal to the number of papers (N) for a researcher that have N or more citations. For example, an h-index of 10 means there are 10 articles that have 10 citations or more. This metric is useful because it discounts the disproportionate weight of highly cited papers or papers that have not yet been cited. It gets increasingly difficult to raise the h-index because the index impacts on all those articles. So, in order for that h-index of 20 to rise to 21, each of those 21 articles now needs to have individual citations of 21 or more.

So let’s suppose we imagine the CORE-OM as a researcher – what would be the h-index for the CORE-OM? Does this give us an idea of one aspect – there are many others – of the impact of the CORE-OM?

Well, like everything, nothing is straightforward. But a simple search on the term ‘CORE-OM’ in SCOPUS yields an h-index of 20 (one article was excluded as not relating to the CORE-OM). So, 20 articles using the CORE-OM have each been cited on SCOPUS at least 20 times.

The top 2 publications, each cited over 200 times, understandably relate to the key initial articles on the development of the CORE-OM and published in the British Journal of Psychiatry (2002) and the Journal of Consulting and Clinical Psychology (2001).

However, some key papers, particularly those early on, did not explicitly use the term ‘CORE-OM’, and some articles might use the CORE-OM in their report but not cite it in the Abstract, which is the usual source for electronic searches to pick up related work. Some early work was not identified, as some journals are not sampled by SCOPUS. However, there was the slightly inexplicable exclusion of an article containing ‘CORE-OM’ in the title!

So a slightly wider search (together with some filtering as more inclusive search terms collect work that is not relevant) yielded an h-index of 23. This search strategy picked up 2 early publications relating to the CORE-OM, both of which appeared in Journal of Mental Health (1998, 2000). However, even this search did not pick up some important articles that used other versions of the CORE-OM, in particular the Short Form A and B versions.

In contrast, a search of ‘CORE-OM’ on Web of Science yielded an h-index of 22 after a couple of papers were deleted as the research did not focus on the CORE-OM. The top 2 articles were the same as in the SCOPUS search. However, WoS does not search Journal of Mental Health, so some of the early work is not detected regardless of extending the search terms, but the search did pick up interesting work using the Short Form versions of the CORE-OM.

So, it would seem that we can say that the CORE-OM has an h-index of 23 according to SCOPUS and 22 for Web of Science. Although the profile of articles for each database is slightly different, the slightly higher h-index for SCOPUS is consistent with the database having a wider scope than WoS – you will likely find the same if you establish the h-index for your own research.

So, what does this mean for the impact of the CORE-OM?

Well, Hirsch suggested that after 20 years of research, an h index of 20 is good, 40 would be outstanding, and 60 exceptional. So, on these simply guidelines, in less than 20 years, the CORE-OM has had a good impact.

All-in-all, I guess that’s not bad. Using the h-index in this way is not as precise as applying it to researchers (they are either an author or not). So the role of the CORE-OM in the articles varies and of course it is only one (imperfect) index of the impact that the CORE-OM has had.

If readers have examples of the impact that the CORE-OM has had for their work or practice, then let us know – we would be very interested to hear from you.

Thank you



New CORE publications

Welcome to 2015 and to the new CORE System Trust website.

One of the many aims of this collective blog is to flag up work that is relevant or cognate to CORE. Two journals that are very good resources for psychotherapy research and for CORE in particular are Psychotherapy Research, the journal of the Society for Psychotherapy Research (SPR), and Counselling and Psychotherapy Research, which is the research journal of the British Association for Counselling and Psychotherapy (BACP). While they are both worth scanning regularly, each has a special issue/section that might be of special interest to readers.

The first issue of Psychotherapy Research in 2015 carries a special issue on Building collaboration and communication between researchers and clinicians edited by Louis G Castonguay and Christopher Muran. This enterprise is one that captures the philosophy of CORE and so it is good to have CORE represented in the special issue.

I recall Louis first raising the possibility of contributing an article in this special issue when we were heading down from Sheffield to the Savoy Conference in London in early December 2010. It was in the midst of one of the worst winters and Sheffield was virtually cut off by snow. Louis, Bill and Sue Stiles, and I waded knee-deep through snow from the Kenwood Hotel to Sheffield Station and were fortunate to get one of the few trains out of Sheffield, eventually arriving somewhat late at the conference. As I recall, Louis’s talk was rescheduled to the afternoon but had kept very well on ice and was as good as ever.

In any event, it’s clearly been a long gestation period for this special issue to arrive but there is plenty for folk to assimilate. Specifically, the 2nd article in the special issue focuses on CORE and, in particular, on issues arising from its implementation in Sweden and the UK:

  • Holmqvist, R., Philips, B., & Barkham, M. (2015). Developing and delivering practice-based evidence: Observations, tensions, and challenges. Psychotherapy Research, 25, 20-31. DOI: 1080/10503307.2013.861093

The article is freely available to members of the Society for Psychotherapy Research (SPR) or through university libraries that carry a subscription. If these fail, email me ( and I will forward a copy.

On a similar theme, the September 2014 issue of Counselling and Psychotherapy Research carried a special section on Practice-based Research Networks. There is a small collection of 5 articles that includes a brief overview of practice-based research networks. As an aside, in researching the introduction to this special section I discovered the pioneering work of Will Pickles – check him out – absolutely fascinating.

Anyway, there are two articles in the section that incorporate work using different versions of CORE. One is an article on individualized patient progress system incorporating CORE-5:

  • Sales, C.M.D., Alves, P.C.G., Evans, C., Elliott, R., & On Behalf of Ipha Group (2014) The Individualised Patient-Progress System: A decade of international collaborative networking. Counselling and Psychotherapy Research, 14, 181-191, DOI: 10.1080/14733145.2014.929417

The other is an article using the YP-CORE in schools:

  • Cooper, M., Mcginnis, S., & Carrick, L (2014) School-based humanistic counselling for psychological distress in young people: A practice research network to address the attrition problem. Counselling and Psychotherapy Research, 14, 201-211, DOI: 1080/14733145.2014.929415

Have a read and, again, if you have difficulties accessing the articles, email me (

Happy reading and Happy 2015. With Tottenham beating Chelsea 5-3 on New Year’s Day, the signs are already promising!