Table 3.

Adjusted rates of the probability of changing medications and the probability of having a gap in medication use among dually-eligible nursing home residents by coverage status and presence of prior authorization or step therapy requirements, 2006–2008

	2006			2007 and 2008			2006			2007 and 2008
	Covered	Not Covered	P-value	Covered	Not Covered	P-value	No PA or Step	PA or Step	P-value	No PA or Step	PA or Step	P-Value
	Adj. Rate	Adj. Rate		Adj. Rate	Adj. Rate		Adj. Rate	Adj. Rate		Adj. Rate	Adj. Rate
ARBs
Change	0.11	0.35	<0.0001*	0.06	0.30	<0.0001*	0.11	0.35	<0.0001*	0.08	0.09	0.54
Gap	0.21	0.30	<0.0001*	0.18	0.36	<0.0001*	0.20	0.38	<0.0001*	0.18	0.22	0.03
Cholinesterase Inhibitors
Change	0.06	0.12	<0.0001*	0.05	0.17	<0.0001*	0.07	0.06	0.02	0.05	0.12	<0.0001*
Gap	0.24	0.35	<0.0001*	0.17	0.22	0.31	0.22	0.35	<0.0001*	0.17	0.18	0.70
Opioids
Change	0.24	0.32	0.0002	0.17	0.39	0.02	0.25	0.20	0.004	0.17	0.15	0.39
Gap	0.27	0.41	<0.0001*	0.22	0.27	0.52	0.28	0.28	0.99	0.22	0.23	0.46
Osteoporosis Medications
Change	0.18	0.40	<0.0001*	0.05	0.79	0.0001*	0.18	0.29	<0.0001*	0.05	0.15	<0.0001*
Gap	0.33	0.40	0.26	0.24	0.55	0.02	0.33	0.38	0.01	0.24	0.23	0.47
Anti-depressants
Change	0.20	0.37	<0.0001*	0.13	0.48	<0.0001*	0.21	0.24	0.03	0.13	0.17	0.0002
Gap	0.18	0.22	<0.0001*	0.15	0.32	<0.0001*	0.18	0.20	0.20	0.15	0.16	0.61
Anti-psychotics
Change	0.14	0.22	0.02	--	--	--	0.14	0.14	0.84	0.09	0.17	<0.0001*
Gap	0.25	0.35	0.03	--	--	--	0.26	0.24	0.07	0.20	0.22	0.16

^*Results that remain statistically significant after correcting for multiple comparisons using the Bonferroni correction.

Notes: Prior authorization and step therapy are only required for covered drugs, so we assess whether prior authorization or step therapy was required conditional on plan coverage. We were unable to estimate models for atypical antipsychotic users in 2007/2008 due to a very small number of individuals whose atypical antipsychotic medication was not covered by their new plan.