Allopurinol reduces the risk of myocardial infarction (MI) in the elderly: a study of Medicare claims

Table 5 Incident allopurinol use and the risk of incident myocardial infarction (MI)* limited to patients with a diagnosis of gout

	Univariate		Multivariable-adjusted (model 3)**		Multivariable-adjusted (model 4)**
	HR (95 % CI)	P value	HR (95 % CI)	P value	HR (95 % CI)	P value
Age (in years)
65 to <75	Ref		Ref		Ref
75 to <85	1.46 (1.29, 1.65)	<0.0001	1.37 (1.21, 1.55)	<0.0001	1.37 (1.21, 1.55)	<0.0001
≥85	2.04 (1.76, 2.36)	<0.0001	1.88 (1.62, 2.19)	<0.0001	1.88 (1.62, 2.19)	<0.0001
Gender
Male	Ref		Ref		Ref
Female	0.98 (0.88, 1.10)	0.77	0.88 (0.79, 0.99)	0.03	0.88 (0.79, 0.99)	0.03
Race
White	Ref		Ref		Ref
Black	1.22 (1.05, 1.43)	0.01	1.16 (0.10, 1.36)	0.06	1.16 (0.99, 1.35)	0.07
Other	0.84 (0.70, 1.06)	0.16	0.86 (0.70, 1.05)	0.14	0.85 (0.69, 1.05)	0.12
Charlson- Romano index score	1.15 (1.14, 1.1.7)	<0.0001	1.15 (1.13, 1.16)	<0.0001	1.15 (1.13, 1.16)	<0.0001
Statins	0.87(0.65, 1.15)	0.31	0.84 (0.63, 1.13)	0.25	0.84 (0.63, 1.12)	0.24
Beta blockers	1.06 (0.81, 1.38)	0.68	1.01 (0.76, 1.34)	0.96	1.01 (0.76,1.34)	0.97
Diuretics	1.00 (0.77, 1.30)	0.99	0.91 (0.70, 1.20)	0.50	0.91 (0.69, 1.19)	0.49
ACE inhibitors	1.43 (1.09, 1.88)	0.01	1.61 (1.22, 2.13)	0.0008	1.61 (1.22, 2.12)	0.009
Allopurinol use	0.84 (0.74, 0.94)	0.003	0.81 (0.72, 0.91)	0.0004	-	-
Allopurinol use duration
0 days	Ref		-	-	Ref
1–180 days	0.94 (0.80, 1.11)	0.47			0.92 (0.78, 1.09)	0.33
181 days to 2 years	0.83 (0.72, 0.97)	0.01			0.79 (0.68, 0.92)	0.002
> 2 years	0.68 (0.54, 0.86)	0.001			0.68 (0.53, 0.85)	0.001

*Incident MI is defined as no MI within the baseline period of 365 days before the index date of allopurinol episode
**Model 3 = allopurinol use (yes versus no) + age + race + gender + Charlson-Romano index score + beta blockers + diuretics + ACE inhibitors + statins
**Model 4 = allopurinol use duration + age + race + gender + Charlson-Romano index score + beta blockers + diuretics + ACE inhibitors + statins
Significant odds ratios and p values are in bold
- Not in the model, ACE angiotensin-converting enzyme, CI confidence interval, HR hazard ratio, Ref reference category
Allopurinol use duration of “0 days” represents the period where a person was not using allopurinol. This could be because they had not received their first prescription when we started observing them or because they went more than 30 days without getting a new prescription; they would begin contributing to the “0 days” category on day 31 of interruption of their allopurinol prescription

ISSN: 1478-6362