The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium: design and rationale of a consortium using individual participant data from prospective cohort studies.

The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium: design and rationale of a consortium using individual participant data from prospective cohort studies.


M.M.A. van Buuren, H. Ahedi, V. Arbabi, N.Arden, S.M.A. Bierma-Zeinstra, C.G. Boer, F.M. Cicuttini, T.F. Cootes, D.T.Felson, W.P. Gielis, G. Jones, N.E. Lane, C. Lindner, J. Lynch, J. van Meurs,A.E. Nelson, M.C. Nevitt, E.H. Oei, N.S. Riedstra, J. Runhaar, T.D. Spector, J.Tang, H. Weinans, R. Agricola.


Osteoarthritis (OA) is the most prevalentjoint disease, affecting at least 500 million people worldwide. Partly due to alack of knowledge on its etiology, OA is incurable, and symptomatic treatmentshave only limited effect. Although hip OA is associated with the highest levelof disability across all joints, considerably less research has been done inthis field in comparison to knee OA. The Worldwide Collaboration onOsteoArthritis prediCtion for the Hip (World COACH) consortium (Fig. 1) was established to collect andharmonize data from all prospective cohort studies that have data relevant tohip OA available. The consortium aims to better understand determinants andrisk factors for development and progression of hip osteoarthritis, as well asto optimize and automate methods for imaging analysis of the hip. This will bepursued through multiple separate research questions and studies within theconsortium.


Prospective cohort studies were consideredeligible if they had hip imaging (radiographs, computed tomography and/ormagnetic resonance imaging) available at two or more points in time, at leastfour years apart, and if they had a minimum of 200 participants. We haveconducted a systematic literature search in Embase, Ovid MEDLINE and CochraneCENTRAL to identify all studies that fulfilled the inclusion criteria. Thesearch was first carried out in 2017 and repeated in October 2020. Titles andabstracts were screened independently by two researchers, and all describedcohorts were further investigated, both by reading the full texts and byadditional internet searches. Investigators from eligible cohorts were contactedand asked to collaborate. Meetings were held with the collaborators toestablish the aims of the consortium and the concrete research plans. Legalagreements for data sharing were drafted and executed. Individual participantdata were collected, pooled, and harmonized into a single database.


We screened the titles and abstracts of 1,970references, from which 195 records were selected for further inspection. Of the39 identified study cohorts, 10 were considered eligible. So far, 8 cohorts havebeen included in the consortium, and contact with the other 2 studies has beenmade. The 8 cohorts currently included in the World COACH consortium contain 40,555participants (aged 35 to 80 years at baseline), of which 34,018 participants hadbaseline pelvic radiographs available. In total, 71% of participants werewomen, and follow-up duration ranged from 7 up to 25 years, with some studiesstill ongoing (Table 1). Otheravailable imaging data include computed tomography (CT) scans, magneticresonance imaging (MRI), and dual-energy X-ray absorptiometry (DXA) of thehips. We will also collect data on comorbidities, pain, family history, qualityof life, physical activity, genetic, and biochemical markers.


The World COACH consortium offers uniqueopportunities for research on the development and/or progression of hip OA. Futuregoals that could be achieved are: better insight in hip OA development andprogression (by studying determinants and risk factors using harmonizedindividual participant data), identification of high- and low-risk subgroupsfor hip OA, the creation of personalized hip OA prediction models, and the developmentof improved methods to automatically analyze radiological imaging of the hip.


Table 1: Characteristics of the included cohorts