Table 1.

Demographic Characteristics, Comorbidities, and Health Services Utilization^* of Women Initiating Weekly Alendronate or Risedronate and Adherent^**

	Alendronate (n = 12,956) N (%)	Risedronate (n = 6,107) N (%)	P value
Demographics
Age			< 0.0001
65–74	7488 (57.8)	3287 (53.8)
≥ 75	5468 (42.2)	2820 (46.2)
Prior Fracture
Hip	259 (2.0)	133 (2.2)	0.42
Wrist/Forearm	201 (1.6)	73 (1.2)	0.05
Clinical Vertebral	333 (2.6)	172 (2.8)	0.29
Non-hip, non-vertebral	486 (3.8)	221 (3.6)	0.65
Any non-vertebral	619 (4.8)	294 (4.8)	0.91
Osteoporosis diagnosis	5635 (43.5)	2623 (43.0)	0.48
Other Selected Comorbidities
Diabetes	1305 (10.1)	701 (11.5)	0.003
Rheumatoid Arthritis	386 (3.0)	179 (2.9)	0.55
Hyperlipidemia	4040 (31.2)	1948 (31.9)	0.32
Tobacco abuse	71 (0.6)	49 (0.8)	0.04
Hyperthyroidism	155 (1.2)	72 (1.2)	0.92
Charlson Comorbidity Index, mean ± SD***	0.64 ± 1.2	0.70 ± 1.3	0.002
Prior Use of Selected Medications
Systemic Estrogen	1622 (12.5)	752 (12.3)	0.69
Teriparatide	4 (0.0)	5 (0.1)	0.13
Raloxifene	328 (2.5)	160 (2.6)	0.72
Nasal calcitonin	363 (2.8)	166 (2.7)	0.74
Systemic Glucocorticoids	1110 (8.6)	589 (9.6)	0.01
Health Services Utilization*
Outpatient visits, mean ± SD	3.5 ± 3.1	3.7 ± 3.3	0.0003
Any hospitalization	1049 (8.1)	533 (8.7)	0.14
Bone Mineral Density Test	5904 (45.6)	3108 (50.9)	< 0.0001
Other Screening Tests
Mammography	3460 (26.7)	1748 (28.6)	0.01
Colonoscopy	610 (4.7)	300 (4.9)	0.54
Fecal Occult Blood Test	1794 (13.9)	776 (12.7)	0.03
Flexible Sigmoidscopy	63 (0.5)	24 (0.4)	0.37

The chi-square test was used to compare categorical variables and t-tests for continuous variables

^*all factors assessed in the 6 months prior to first bisphosphonate use

^**defined as having no more than a 15 day gap after the end of one prescription until the next prescription was filled

^***the Charlson comorbidity index is an aggregate sum of pre-defined medical comorbidities, from (16)