Table 3 Characteristics of the study population and concurrent exposures.
| Characteristics | Arthritis group | Control group | p Value |
|---|---|---|---|
| (n = 1939) | (n = 207 072) | ||
| Female (%) | 51.4 | 53.1 | 0.15 |
| Age at 1st recorded diagnosis, mean (SD) | 10.9 (5.2) | – | – |
| Age at start of follow up | 17.3 (1–96) | 19.7 (0–104) | 0.005 |
| Follow up duration (years)* | 3.90 (0.003–14.0) | 3.95 (0.003–14.0) | >0.2 |
| Fracture before follow up (%)† | 7.1 | 3.2 | <0.001 |
| DMARD treatment (%)‡ | 5.7 | – | – |
| Glucocorticoid treatment (%) | 4.9 | – | – |
| NSAID treatment (%) | 54.0 | 12.7 | <0.001 |
Medians and ranges provided, unless otherwise noted.
*Follow up duration was calculated as follows: (date that the subject has first fracture, dies, leaves the eligible practice, or that the practice is no longer up to standard (UTS) − date of start of follow up)/365.25; †assessed as fractures during UTS or non‐UTS periods; ‡DMARDs include methotrexate, ciclosporin, sulfasalazine, and tumour necrosis factor α inhibitors.