Table 4

Association of risk factors with hazard of atrial fibrillation in patients who received allopurinol with no baseline atrial fibrillation before the index date of allopurinol episode

 UnivariateMultivariable-adjusted (model 1)Multivariable-adjusted (model 2)
HR (95% CI)p ValueHR (95% CI)p ValueHR (95% CI)p Value
Age (in years)
 65–<75RefRefRef
 75–<851.47 (1.31 to 1.66)<0.00011.43 (1.27 to 1.62)<0.00011.43 (1.27 to 1.61)<0.0001
 ≥852.12 (1.83 to 2.46)<0.00012.04 (1.75 to 2.37)<0.00012.04 (1.75 to 2.38)<0.0001
Gender
 MaleRefRefRef
 Female1.04 (0.93 to 1.15)0.500.95 (0.85 to 1.06)0.350.95 (0.85 to 1.06)0.31
Race
 WhiteRefRefRef
 Black0.83 (0.70 to 0.97)0.020.79 (0.67 to 0.93)0.00380.79 (0.67 to 0.92)0.003
 Other0.69 (0.58 to 0.83)<0.00010.65 (0.55 to 0.78)<0.00010.65 (0.54 to 0.78)<0.0001
Charlson–Romano score, per unit change1.10 (1.08 to 1.11)<0.00011.09 (1.08 to 1.11)<0.00011.09 (1.08 to 1.11)<0.0001
Statins0.95 (0.72 to 1.24)0.690.87 (0.66 to 1.16)0.360.87 (0.66 to 1.16)0.35
β-blockers1.58 (1.22 to 2.05)0.00051.60 (1.22 to 2.11)0.00081.60 (1.22 to 2.10)0.0008
Diuretics1.09 (0.85 to 1.40)0.510.98 (0.75 to 1.28)0.860.97 (0.74 to 1.27)0.85
ACE inhibitors0.99 (0.72 to 1.36)0.950.99 (0.71 to1.37)0.930.98 (0.71 to1.37)0.92
Allopurinol0.86 (0.77 to 0.97)0.010.83 (0.74 to 0.93)0.0013
Allopurinol duration*
 0 daysRefRef
 1–180 days0.94 (0.80 to 1.11)0.460.92 (0.78 to 1.09)0.32
 181 days–2 years0.90 (0.77 to 1.04)0.160.85 (0.73 to 0.99)0.03
 >2 years0.68 (0.54 to 0.65)0.00090.65 (0.52 to 0.82)0.0002
  • Ref, referent category.

  • *Based on person-day count.

  • Model 1=Allopurinol use+age+race+gender+Charlson–Romano score+β-blockers+diuretics+ACE inhibitors+statins.

  • Model 2=Allopurinol duration+age+race+gender+Charlson–Romano score+β-blockers+diuretics+ACE inhibitors+statins.

  • Bold indicates statistically significant associations with a p-value of <0.05.