Overview of all participating studies
| Study (stage) | Reference article | Study design | Ethnic origin | Country of origin | Medication | Age/BMI | Mean age (y) | No. of CWP cases | No. of CWP controls |
|---|---|---|---|---|---|---|---|---|---|
| Stage 1 | |||||||||
| ERF study | 32 | Family based cohort | Caucasian | The Netherlands | Y | Y | 46.4 | 149 | 665 |
| RS-I | 33 | Population based cohort | Caucasian | The Netherlands | Y | Y | 69.4 | 563 | 1892 |
| RS-II | 33 | Population based cohort | Caucasian | The Netherlands | Y | Y | 67.9 | 110 | 668 |
| RS-III | 33 | Population based cohort | Caucasian | The Netherlands | Y | Y | 56.3 | 85 | 868 |
| TwinsUK | 34 35 | Twins based cohort | Caucasian | UK | Y | Y | 51.9 | 401 | 1698 |
| Total no. of samples | 59.7 | 1308 | 5791 | ||||||
| Stage 2a | |||||||||
| 1958BC | 23 36–38 | Prospective birth cohort | Caucasian | UK | N | Y (born in 1958) | NA | 315 | 2206 |
| AGES | 43 | Population based cohort | Caucasian | Iceland | Y | Y | 76.5 | 173 | 1204 |
| DSDBAC | 41 | Population based cohort | Caucasian | UK | Y | Age only | 80.1 | 81 | 219 |
| FOA | 44 | Population based cohort | Caucasian | USA | Y | Y | 59.3 | 384 | 814 |
| GARP | 45 | Case control based | Caucasian | The Netherlands | Y | Y | 58.5 | 67 | 925* |
| SHIP | 46 47 | Population based cohort | Caucasian | Germany | Y | Y | 57.6 | 183 | 589 |
| Stage 2b | |||||||||
| CHINGFORD | 39 40 | Population based cohort | Caucasian | UK | Y | Y | 56.6 | 48 | 337 |
| EPIFUND | 20 | Population based cohort | Caucasian | UK | N | Age only | 49.0 | 139 | 503 |
| HCS | 42 | Population based cohort | Caucasian | UK | Y | Y | 66.4 | 90 | 2117 |
| Total no. of samples | 1480 | 7989 | |||||||
*GARP consists of clinical and radiographically confirmed osteoarthritis case only; therefore we used 925 randomly chosen Rotterdam Study samples as controls.
Age/BMI Y, age and BMI data are available; Age only, no BMI data are available; AGES, Age, Gene/Environment Susceptibility study Reykjavik; BMI, body mass index; CWP, chronic widespread pain; CHINGFORD, Chingford 1000 Women Study; DSDBAC, Dyne Steel DNA Bank for Ageing and Cognition; ERF study, Erasmus Rucpen Family study; EPIFUND, EPIdemiological study of FUNctional Disorders study; HCS, Hertfordshire Cohort Study; FOA, Framingham Osteoarthritis Study; GARP, Genetics OsteoArthritis and Progression study Leiden; Medication Y, information about medication use available; Medication N, medication use not available; RS, Rotterdam Study; SHIP, Study of Health In Pomerania; TwinsUK, the UK Adult Twin Registry; 1958BC, 1958 Birth Cohort.