Table 1.

Cohort characteristics

CharacteristicUrolithiasis (n=51,785)No Urolithiasis (n=517,267)P Value
Age at start of follow-up (yr)53 (40, 64)53 (40, 64)
Male sex66.966.8
Country
 England7878
 Ireland33
 Scotland1313
 Wales55
Follow-up time (yr)4.7 (2.1, 9.0)4.7 (2.1, 8.7)
History of prior fracture21.018.8<0.001
Covariate exposures
 Diabetes mellitus9.26.1<0.001
 Gout3.93.0<0.001
 Cystic fibrosis0.070.03<0.001
 Prematurity/low birth weight0.220.15<0.001
 Primary hyperparathyroidism0.700.07<0.001
 Sarcoidosis0.370.22<0.001
 Inflammatory bowel disease1.950.91<0.001
 Malabsorption0.110.04<0.001
 Chronic immobility1.220.75<0.001
Covariate medications
 Loop diuretic7.06.0<0.001
 Systemic corticosteroids14.613.1<0.001
 Topiramate0.140.06<0.001
  • Data are presented as the median (interquartile range) or percentage. P values were calculated with the chi-square test.