17 August 2020

New publication from the APPROACH consortium

A new publication from the APPROACH project has been published by the British Medical Journal (BMJ). The article describes the APPROACH study and cohort characteristics.

Cohort profile: The Applied Public-Private Research enabling OsteoArthritis Clinical Headway (IMI-APPROACH) study: a 2-year, European, cohort study to describe, validate and predict phenotypes of osteoarthritis using clinical, imaging and biochemical markers

Eefje M van Helvoort, Willem E van Spil, Mylène P Jansen, Paco M J Welsing, Margreet Kloppenburg, Marieke Loef, Francisco J Blanco, Ida K Haugen, Francis Berenbaum, Jaume Bacardit, Christoph H Ladel, John Loughlin, Anne C Bay-Jensen, Ali Mobasheri, Jonathan Larkin, Janneke Boere, Harrie H Weinans, Agnes Lalande, Anne C A Marijnissen, Floris P J G Lafeber

Available here.


Cohort profile: The Innovative Medicines Initiative (IMI) – Applied Public-Private Research enabling OsteoArthritis Headway (APPROACH) study


Currently, all patients with osteoarthritis (OA) are treated in a similar way, and this treatment is mainly symptomatic rather than curative. The main challenges in the development of new drugs are the great variety in symptoms and disease progression, the lack of proper measurements to evaluate effectiveness, and the variability in causes of the disease among patients, resulting in a highly mixed population. In other words, there are multiple ‘subgroups’ of OA, with different causes, so called phenotypes. One can easily imagine that OA patients with different causes for their disease, need different treatments


The IMI-APPROACH study wants to take a first step in improving the development of new OA treatments. It is an international project, combining the expertise of industry, academia, and patients from all over Europe. The study will take place in five centres in four different countries: Utrecht (NL), Leiden (NL), Á Coruña (E), Oslo (N), and Paris (F). The main objective of the IMI-APPROACH study is to define those phenotypes. In order to do that, the IMI-APPROACH study used a novel and unique two-step selection process. First, participants were ranked using a so-called Machine Learning model, based on data collected during previous OA studies. Higher ranking indicates better suitability to participate in the study. Second, the highest ranked participants were invited for a screening visit. During this visit additional (and recent) data was collected and again, a Machine Learning model was used to rank all participants and the highest ranked participants were included in the study. These participants will visit the hospital four times in two years. During their visits a large amount of data will be collected: conventional radiographs, MRI-scans, CT-scans, blood, urine, questionnaires, function tests and a physical examination will be performed.

Cohort characteristics

In total, 297 participants were included. 230(=77%) are female. The mean age is 66.5 years (range 44-82) and mean BMI is 28.1 (range 18.3-47.5). Knee radiographs were evaluated using the Kellgren & Lawrence OA grade (0=normal, 4=worst) and measuring the minimal distance between the upper and lower leg: the minimum joint space width (minJSW). A smaller minJSW indicates less cartilage, so more cartilage loss due to OA. Grade 0 was seen in 17% of the participants, grade 1 in 30%, grade 2 in 30%, grade 3 in 18% and grade 4 in 3%. The mean minJSW in the whole cohort is 2.5mm (around 4mm in knees without OA). On a pain-scale from 0 (no pain) to 10 (worst imaginable pain) the mean pain score is 4.6.