Table 4

 Relative risk (RR) estimates for risk factors by age

RR† by age
Data are presented only for those risk factors and age groups for which the lower confidence bound of the relative risk estimate was greater than 1.
*Diagnosis recorded at any time before index date (except for road collisions, which were recorded within 90 days before index date).
†Relative risk estimates are conditional on the matching factors (age, sex, general practice, index date, and duration of follow up in GPRD before index date) and adjusted for all other risk factors.
‡Any prescription for drug in therapeutic class recorded within 30 days before index date.
¶Reference: non-smokers.
§Body mass index (kg/m2); reference: BMI <24.
    Rheumatoid arthritis1.6
    Road collision16.
Other characteristics
    Smoking unknown¶
    BMI 24–28§1.2
    BMI >28§1.4
    BMI unknown§1.1