Patterns and predictors of osteoporosis medication discontinuation and switching among Medicare beneficiaries

Table 3 Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between precipitating factors and discontinueation of bisphosphonate therapy, case-crossover analysis

Factors potentially associated with discontinuation^a	Univariate analysis	Multivariate analysis
	OR (95% CI)	Adjusted^bOR (95% CI)
Dual-energy X-ray absorptiometry	2.0 (1.3-3.1)	2.3 (1.4-3.6)
Any hospitalization	2.2 (1.5-3.1)	1.7 (1.1-2.7)
Fracture	0.7 (0.2-1.9)	0.4 (0.1-1.3)
Cancer	1.2 (0.7-1.9)	1.0 (0.6-1.8)
Entering Medicare part D coverage gap	1.0 (0.8-1.3)	0.9 (0.7-1.3)
Adverse effects	1.6 (1.1-2.3)	1.0 (0.7-1.6)
Skilled nursing home	0.7 (0.2-2.1)	0.4 (0.1-1.4)
Rheumatologist or endocrinologist visit	1.1 (0.7-1.7)	0.8 (0.5-1.4)
Upper gastrointestinal disease	3.2 (1.4-7.3)	3.4 (1.5-7.7)
Eligible for low income subsidy	4.9 (0.8-28.7)	5.7 (1.0-32.4)
Number of ambulatory physician visits during each 30 day period
0	Ref (1.0)	Ref (1.0)
1-4	1.2 (1.0-1.4)	1.2 (1.0-1.5)
> 4	2.4 (1.4-4.1)	2.5 (1.3-4.5)
Number of medications during each 30 day period
0-2	Ref (1.0)	Ref (1.0)
3-5	0.8 (0.7-1.0)	0.5 (0.4-0.6)
> 5	0.5 (0.4-0.7)	0.3 (0.2-0.4)
Charlson score during each 30 day period
0	Ref (1.0)	Ref (1.0)
1-2	1.3 (0.8-1.9)	1.4 (0.9-2.1)
> 2	1.7 (1.0-3.1)	2.5 (1.3-4.7)
Total Medicare cost during each 30-day period
$ 0-90	Ref (1.0)	Ref (1.0)
$ 91-440	0.9 (0.7-1.1)	0.9 (0.7-1.1)
$ > 440	1.0 (0.8-1.3)	0.9 (0.8-1.3)
Out-of-pocket drug payments during each 30 day period
$ 0-19	Ref (1.0)	Ref (1.0)
$ 20-84	1.6 (1.2-2.0)	1.6 (1.3-2.1)
$ > 84	5.4 (4.4-6.7)	6.6 (5.3-8.1)

^aHazard period is defined as 30 days immediately before discontinuation. Control periods are defined as five 30-day periods immediately before the hazard period.
^bAdjusted all the factors listed in the table.

ISSN: 1471-2474