Background In the Netherlands, a prospective 10-year follow-up study was initiated and funded by the Dutch Arthritis Foundation (DAF) in order to establish the course of early symptomatic osteoarthritis (OA) in participants with early complaints of hip and/or knee: CHECK (Cohort Hip & Cohort Knee). To understand more about the disease and its course, we initiated a large independent detailed observational study starting (very) early in the stage of the disease and where subjects were characterized in 3 main domains through-out follow-up: clinical, radiographic and biochemical biomarkers.
Objectives We present the results of 7 years of follow up.
Methods Between October 2002 and September 2005 a cohort was formed of 1002 participants aged 45-65 years with symptomatic OA characterized by pain and/or stiffness of knee and/or hip. They were included at the first visit or within 6 months of the first visit to the general practitioner for these symptoms. Study centers comprise ten general and university hospitals located in urbanized and semi-urbanized regions in the Netherlands. A special program was developed to minimize loss to follow up, comprising newsletters, website and organizing symposia to present the results and progress of CHECK. An overview of measures that are included in the study can be found at our website www.check-research.com.
Results After 7 years a total of 105 (10%) participants had dropped out. Reasons included loss of interest (21%), comorbidity that complicated participating of CHECK too much (18%), death (12%), contact lost (11%), costs incurred for the study (5%), and other reasons (33%). Dropouts did not differ significantly from other participants in baseline characteristics. Over 7 years follow-up clinical characteristics including pain, stiffness and function of disease-specific (WOMAC) and the subscales of generic self-report questionnaire (SF36) on average did not change significantly, although at least half of the patients experienced radiographic progression. Scoring of 5-year follow up is complete: at this point, 50% of the participants progressed by at least one Kellgren and Lawrence grade in the knee, and 25% in the hip. Preliminary analyses suggest the existence of several clinical and radiological phenotypes.
Conclusions CHECK is a valuable source of information of early symptomatic OA with a low loss to follow-up and a multidisciplinary approach that allows the collections of high-quality data on clinical, radiological and biochemical variables.
Acknowledgements CHECK-cohort study is initiated by the Dutch Arthritis Foundation and performed within; Erasmus Medical Center Rotterdam; Kennemer Gasthuis Haarlem; Leiden University Medical Center; Maastricht University Medical Center; Martini Hospital Groningen/Allied Health Care Center for Rheum. and Rehabilitation Groningen; Medical Spectrum Twente Enschede/Ziekenhuisgroep Twente Almelo; Reade, formerly Jan van Breemen Institute/VU Medical Center Amsterdam; St.Maartens-kliniek Nijmegen; University Medical Center Utrecht and Wilhelmina Hospital Assen.
Disclosure of Interest None declared