Table 5 Sensitivity of fracture incidence rate ratio* estimates to more restrictive assessments of arthritis diagnoses.
| Age category (years) | During UTS† | Two diagnoses‡ | NSAIDs prescribed |
|---|---|---|---|
| (n = 844) | (n = 381) | (n = 1047) | |
| <10 | 1.84 (1.09 to 2.93) | 0.98 (0.20 to 2.86) | 1.34 (0.58 to 2.65) |
| 10–15 | 2.86 (1.79 to 4.36) | 2.29 (0.99 to 4.54) | 2.54 (1.55 to 3.94) |
| 15–20 | 1.86 (1.06 to 3.02) | 1.32 (0.43 to 3.10) | 1.66 (1.02 to 2.55) |
| 20–45 | – | 1.03 (0.28 to 2.64) | 1.40 (0.77 to 2.36) |
| >45 | – | 5.56 (1.79 to 13.17) | 3.60 (1.63 to 6.95) |
| Test for heterogeneity | p>0.2 | p = 0.04 | p = 0.09 |
| Combined estimate§ | 2.15 (1.65 to 2.80) | – | – |
*IRR (95% confidence interval); †subjects ⩾20 years at the start of follow up were not analysed because of the small number of subjects with arthritis (n = 10, no fractures); ‡more than 6 weeks apart; §the Mantel‐Haenszel combined estimate is provided when there is homogeneity across age category strata.