Threads and yarns is a research network which pulls together primary care researchers across several European countries with a common interest in research for informing the provision of best health care for people with complex clinical status. The origin of the network lies in the International Primary Care Research Leadership programme hosted by the University of Oxford, and which originated as part of the Brisbane Initiative, an international collaboration of universities which aim to foster and develop future leaders in primary care research. The international programme put in contact researchers with a common interest, stimulated discussions and fostered a collaboration that has resulted in this network.

"Threads and yarns" is the image that Prof. Barbara Starfield proposed for the study of multi-morbidity (Starfield B, Ann Fam Med, 2006):

"As any weaver knows, the elegance of a fabric lies in the yarns, not the threads. The whole is lots more than the sum of its parts. In health services, the threads are the diagnoses on which interventions are based. How these threads are spun into yarn (the underlying biodynamic of the tapestry of health) is poorly understood, to the detriment of efforts to understand the genesis of health problems and the interventions associated with them."

Central to this metaphor is the fact that while each individual clinical diagnosis is relevant for determining the health care needs of a person, the presence of multi-morbidity makes necessary to consider an additional level of complexity.


This network was founded by researchers from ten institutions in Germany, Ireland, the Netherlands, Spain and the United Kingdom. It covers interests in different areas of research in Primary Care with selected population, disease and methods and implementation focus. The founding members are listed below in alphabetical order:

Dr. Jeanette Blom (Leiden, Netherlands)
Dr. Michael Freitag (Jena, Germany)
Dr. Liam Glynn (Galway, Ireland)
Prof. Christian Mallen (Keele, UK)
Dr. Christiane Muth (Frankfurt, Germany)
Dr. Alexandra Prados-Torres (Zaragoza, ES)
Dr. Sonia Saxena (London, UK)
Prof. Jose M Valderas (Exeter, UK)
Dr. Marjan van den Akker (Maastricht, Netherlands)
Dr. Concepció Violan (Barcelona, Spain)

 Activities and Dissemination

In February 2011, a one day International Workshop on Research Priorities in Multi-morbidity was hosted in Frankfurt with the participation of Prof. Martin Fortin (Chicoutimi, Canada). Link

Later in 2012, a conference was organized in Frankfurt consisting of two parts:

1. Symposium (17th October): "Evidence Based Medicine Meets Multi-morbidity: A Blind Date?" with invited speakers (Paul Glasziou from Australia, Martin Fortin from Canada, Marjan van den Akker and Francoise Schellevis from The Netherlands and several others) and discussions with invited participants from general practice, primary care research, and healthcare decision makers as well as physicians and researchers from other disciplines, such as pharmacology, pharmacy, geriatrics and gerontology.

2. Workshop (18th to 19th October): "How to address co- and Multi-morbidity in primary care practice?" with a selection of about 20 experts representing different fields of research and family medicine. The invited speakers of the symposium were part of this expert working group



 Selected Projects

Improving the management of patients with multimorbid long term conditions with the clinical use of patient reported outcome measures in Primary Care. Principal Investigator: Valderas JM.

Prioritising and optimising multiple medications in elderly multi-morbid patients in general practice (PRIMUM). - A pragmatic cluster-randomised controlled trial. Principal Investigator: Muth C.

Polyfarmacy Intervention Limburg (PIL). A pragmatic cluster-randomised trial in a stepped wedge design. Principal Investigator: van den Akker M.

Systematic Review of Studies of Multimorbidity Patterns. Principal Investigator: Valderas JM.

Interactions between chronic heart failure and its common co-occurring conditions. Principal Investigator: Muth, C.

 Selected Publications

Multimorbidity's research challenges and priorities from a clinical perspective: The case of Mr. Curran. Muth C, Beyer M, Fortin M, Rochon J, Oswald F, Valderas JM, Harder S, Glynn LG, Perera R, Freitag M, Kaspar R, Gensichen J, van den Akker M. Eur J Gen Prac (Accepted for publication)

Measures of multimorbidity and morbidity burden for use in primary care and community settings: a systematic review and guide. Huntley AL, Johnson R, Purdy S, Valderas JM, Salisbury C. Ann Fam Med 2012 Mar;10(2):134-41. Link

The prevalence of multimorbidity in primary care and its effect on health care utilization and cost. Glynn LG, Valderas JM, Healy P, Burke E, Newell J, Gillespie P, Murphy AW. Fam Pract 2011 Oct; 28(5):516-23. Link

Influence of multimorbidity on cognition in a normal aging population: a 12 year follow-up in the Maastricht Aging Study. Aarts S, van den Akker M, Tan FES, Verhey FRJ, Metsemakers JFM, van Boxtel MPJ. International Journal of Geriatric Psychiatry, 2011;26(10):1046-53. DOI: 10.1002/gps.2642 (IF=1.981) Link

Research on patients with multiple health conditions: different constructs, different views, one voice. Valderas JM, Mercer SW, Fortin M. 2011;1(1) :1-3. Link

Epidemiology and impact of multimorbidity in primary care: a retrospective cohort study. Salisbury C, Johnson L, Purdy S, Valderas JM, Montgomery AA. Br J Gen Pract. 2011 Jan;61(582):e12-21. Link

Multimorbidity, service organization and clinical decision making in primary care: a qualitative study. Bower P, Macdonald W, Harkness E, Gask L, Kendrick T, Valderas JM, Dickens C, Blakeman T, Sibbald B. Fam Pract. 2011 Oct;28(5):579-87. Link

Multimorbidity and its relation to subjective memory complaints in a large general population of older adults. Aarts S, van den Akker M, Hattema KJ, van Ingen AM, Metsemakers JFM, Verhey FRJ, van Boxtel MPJ. International Pscychogeriatrics, 2010 Nov3:1-9 (Epub ahead of print) (IF=2.506) Link

The electronic Cumulative Illness Rating Scale: a reliable and valid tool to assess multi-morbidity in primary care. Fortin M, Steenbakkers K, Hudon C, Poitras ME, Allmiral J, van den Akker M. Journal of Evaluation in Clinical Practice, 2010;doi:10.1111/j.1365-2753.2010.01475.x (IF=1.487). Link

Defining comorbidity: implications for understanding health and health services. Valderas JM, Starfield B, Sibbald B, Salisbury C, Roland M. Ann Fam Med. 2009 Jul-Aug;7(4):357-63. Link

Multimorbidity: another key issue for cardiovascular medicine. Glynn LG. Lancet. 2009 Oct 24;374(9699):1421-2. Link

Multimorbidity and risk among patients with established cardiovascular disease: a cohort study. Glynn LG, Buckley B, Reddan D, Newell J, Hinde J, Dinneen SF, Murphy AW. Br J Gen Pract. 2008 Jul;58(552):488-94. Link

Definitions of chronic health conditions in childhood. Valderas JM, Starfield B, Salisbury C. JAMA. 2007 Oct 10;298(14):1636 Link

Multimorbidity's many challenges: A research priority in the UK. Valderas JM, Starfield B, Roland M. BMJ. 2007 Jun 2;334(7604):1128. Link