Table 3.

Unadjusted Comparisons of Patient Characteristics For New Allopurinol Users Stratified by Adherence

Patient Characteristics	Total	Adherent (PDC ≥80%)	Non-adherent (PDC <80%)	P Value*
	N=10,991a	N= 4,656	N= 6,335
Men (vs. women) n, (%)	8,561 (77.9)	3,504 (75.3)	5,057 (79.8)	0.002*
Patient Age Groups, years, n(%)				<.0001*
<55	4,007 (36.5)	1,315 (28.2)	2,692 (42.5)
55-64	3,588 (32.6)	1,577 (33.9)	2,011 (31.7)
≥65	3,394 (30.9)	1,763 (37.9)	1,631 (25.7)
Race/ethnicity, n(%)				<.0001*
Caucasian	4,540 (41.3)	2,343 (50.3)	2,197 (34.7)
African American	1,712 (15.6)	620 (13.3)	1,092 (17.2)
Hispanic	2,134 (19.4)	728 (15.6)	1,406 (22.2)
Asian/Pacific Islander	2,484 (22.6)	884 (19)	1,600 (25.3)
Other	121 (1.1)	80 (1.7)	41 (0.6)
Comorbidities, n (%)
Hypertension	7,817 (71.1)	3,695 (79.4)	4,122 (65.1)	<.0001*
Myocardial infarction	751 (6.8)	387 (8.3)	364 (5.7)	0.0002*
Congestive heart failure	875 (8)	484 (10.4)	391 (6.2)	<.0001*
Diabetes	2,593 (23.6)	1,332 (28.6)	1,261 (19.9)	<.0001*
Other Covariates
Baseline GFR, ml/min, mean SD	63.6±18.7	67.5±18.3	54.6±18.5	<.0001*
Diuretic use, n(%)	4,329 (39.4)	2,256 (48.5)	2,073 (32.7)	0.004*
Use of baseline anti-inflammatoryb, n(%)	7,650 (69.6)	2,894 (62.2)	4,756 (75.1)	<.0001*
Rheumatologist as initial prescriber, n(%)	656 (6.0)	382 (8.2)	274 (4.3)	<.0001*
Starting Allopurinol Dose, mg/day, n(%)
≤ 100	5,382 (49.0)	2,533 (54.4)	2,849 (45.0)	<.0001*
>100 to < 300	1,450 (13.2)	609 (13.1)	841 (13.3)	0.18
≥ 300	4,158 (37.8)	1,514 (32.5)	2,644 (41.7)	0.002*
Allopurinol Dose Adjustment
Dose escalation	2,994 (27.2)	1393 (21.9)	1601 (34.2)	0.04*

^aPDC was calculated for patients with 2 or more allopurinol dispensings during 12 months post-index (N=10,991).

^banti-inflammatory drugs include non-steroidals, NSAIDs and glucocorticoids.

^*P value was set at <0.05 for statistical significance.

Proportion of days covered (PDC); glomerular filtration rate (GFR); standard deviation (SD).