Table 3.

Univariate analysis of factors influencing heartworm preventative (HWP) use in 1,408 dogs surveyed on presentation to a veterinary teaching hospital between 1999 and 2006.

Variable	n	% on HWP	OR	95% CI	P
Age
Under 6 months	137	48.2	1.00	-	-
6 months – 1 year	124	80.6	4.73	2.83 – 7.90	0.00
1 year – 5 years	473	85.6	6.16	4.17 – 9.10	0.00
5 years – 9 years	357	85.9	6.91	4.57 – 10.4	0.00
9 years – 13 years	289	82.4	5.72	3.75 – 8.73	0.00
Over 13 years	64	76.6	2.89	1.63 – 5.12	0.00
Breed Size
Small	146	80.1	1.00	-	-
Medium	522	83.1	1.13	0.75 – 1.72	0.56
Large	251	76.1	0.78	0.49 – 1.24	0.30
Sex
Female	674	81.2	1.00	-	-
Male	735	80.0	1.01	0.79 – 1.30	0.92
Neuter Status
Neutered	1016	84.4	1.00	-	-
Intact	8	25.0	0.08	0.02 – 0.41	0.00
Median Household Income
$10,000 - $20,000	39	53.8	1.00	-	-
$20,000 - $30,000	110	60.9	1.30	0.64 – 2.65	0.46
$30,000 - $40,000	189	68.3	1.78	0.90 – 3.49	0.09
$40,000 - $50,000	235	78.7	2.94	1.47 – 5.84	0.00
$50,000 - $60,000	180	76.1	2.62	1.30 – 5.29	0.01
$60,000 - $70,000	197	75.1	2.61	1.31 – 5.21	0.01
$70,000 - $80,000	100	75.0	2.46	1.15 – 5.29	0.02
$80,000 - $90,000	55	63.6	1.52	0.67 – 3.42	0.30
$90,000 - $100,000	19	15.7	3.92	0.94 – 16.3	0.04
Over $100,000	43	65.1	1.71	0.72 – 4.04	0.22
Month of Presentation
January	124	80.6	1.00	-	-
February	127	70.1	0.59	0.33 – 1.07	0.08
March	144	63.2	0.35	0.20 – 0.63	0.00
April	152	69.1	0.51	0.29 – 0.90	0.02
May	121	93.4	1.89	0.93 – 3.82	0.07
June	91	91.2	1.85	0.85 – 4.03	0.12
July	138	83.3	0.98	0.53 – 1.81	0.95
August	139	84.2	0.95	0.52 – 1.75	0.88
September	100	86.0	1.16	0.58 – 2.32	0.67
October	97	81.4	0.74	0.39 – 1.40	0.34
November	93	90.3	1.74	0.81 – 3.71	0.14
December	87	86.2	1.23	0.60 – 2.51	0.57