Treatment patterns in Medicaid patients with schizophrenia initiated on a first- or second-generation long-acting injectable versus oral antipsychotic

Figures & data

Figure 1 Identification of the study population.

Notes: ^aLAI agents include first-generation: fluphenazine LAI, haloperidol LAI; second-generation: olanzapine LAI, risperidone LAI, paliperidone LAI, and aripiprazole LAI. ^bInitiation of an antipsychotic agent is defined as having ≥2 claims for the same agent within 90 days and no claim for the same agent during the 12 months before the first claim.
Abbreviations: FGA, first-generation antipsychotics; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; LAI, long-acting injectable therapies; OAP, oral antipsychotics; SGA, second-generation antipsychotics.

Table 1 Demographic and clinical characteristics evaluated during the 12-month baseline period

Characteristic	OAP (A)	FGA-LAI (B)		SGA-LAI (C)
	(N=20,478)	(N=1,089)	P-valuea (A) vs (B)	(N=2,209)	P-valuea (A) vs (C)
Age on index date (years), mean ± SD (median)	44.8±13.2 (46.5)	45.5±12.5 (47.0)	0.080	42.2±12.8 (42.7)	<0.001*
Female, n (%)	10,006 (48.9)	432 (39.7)	<0.001*	875 (39.6)	<0.001*
Race, n (%)
White	10,767 (52.6)	417 (38.3)	<0.001*	1,061 (48.0)	<0.001*
Black	6,913 (33.8)	524 (48.1)	<0.001*	900 (40.7)	<0.001*
Hispanic	867 (4.2)	44 (4.0)	0.757	21 (1.0)	<0.001*
Other	1,055 (5.2)	38 (3.5)	0.015*	156 (7.1)	<0.001*
Unknown	876 (4.3)	66 (6.1)	0.005*	71 (3.2)	0.018*
State, n (%)
Florida	3,543 (17.3)	217 (19.9)	0.026*	93 (4.2)	<0.001*
Iowa	907 (4.4)	128 (11.8)	<0.001*	172 (7.8)	<0.001*
Kansas	1,392 (6.8)	42 (3.9)	0.001*	202 (9.1)	<0.001*
Mississippi	1,895 (9.3)	152 (14.0)	<0.001*	253 (11.5)	<0.001*
Missouri	8,445 (41.2)	376 (34.5)	<0.001*	980 (44.4)	0.005*
New Jersey	4,296 (21.0)	174 (16.0)	<0.001*	509 (23.0)	0.024*
Region characteristics, n (%)
Urban	12,019 (58.7)	639 (58.7)	0.992	1,247 (56.5)	0.042*
Suburban	5,425 (26.5)	289 (26.5)	0.973	572 (25.9)	0.545
Rural	3,034 (14.8)	161 (14.8)	0.977	390 (17.7)	<0.001*
Insurance eligibility, n (%)
Capitated or dual coverage	12,693 (62.0)	632 (58.0)	0.009*	1,466 (66.4)	<0.001*
Capitated	7,750 (37.8)	338 (31.0)	<0.001*	864 (39.1)	0.244
Dual coverage	7,675 (37.5)	423 (38.8)	0.365	910 (41.2)	<0.001*
Year of index date, n (%)
2010	9,726 (47.5)	460 (42.2)	<0.001*	1,080 (48.9)	0.212
2011	5,791 (28.3)	286 (26.3)	0.149	517 (23.4)	<0.001*
2012	2,976 (14.5)	209 (19.2)	<0.001*	330 (14.9)	0.607
2013	1,575 (7.7)	101 (9.3)	0.057	203 (9.2)	0.013*
2014	410 (2.0)	33 (3.0)	0.020*	79 (3.6)	<0.001*
Quan-CCI, mean ± SD (median)	1.3±1.8 (1.0)	0.9±1.5 (0.0)	<0.001*	0.8±1.3 (0.0)	<0.001*
Number of unique mental health diagnoses,b mean ± SD (median)	9.3±8.6 (7.0)	8.0±7.8 (6.0)	<0.001*	8.1±7.6 (6.0)	<0.001*
Number of unique AP agents received, mean ± SD (median)	1.1±1.1 (1.0)	1.3±1.3 (1.0)	0.217	1.5±1.2 (1.0)	<0.001*
AP use, n (%)	13,927 (68.0)	697 (64.0)	0.006*	1,763 (79.8)	<0.001*
FGA oral and short-term injectable APs	4,096 (20.0)	413 (37.9)	<0.001*	393 (17.8)	0.013*
SGA oral and short-term injectable APs	11,906 (58.1)	514 (47.2)	<0.001*	1,447 (65.5)	<0.001*
FGA-LAI	1,578 (7.7)	74 (6.8)	0.271	291 (13.2)	<0.001*
SGA-LAI	1,115 (5.4)	73 (6.7)	0.076	488 (22.1)	<0.001*
Proportion of days covered (PDC) by any AP agent, n (%)
PDC <80%c	8,709 (62.5)	457 (65.6)	0.106	1,182 (67.0)	<0.001*
PDC ≥80%c	5,218 (37.5)	240 (34.4)	0.106	581 (33.0)	<0.001*
AP polypharmacy present,d n (%)	2,867 (14.0)	201 (18.5)	<0.001*	430 (19.5)	<0.001*
Other psychiatric medication use, n (%)	15,746 (76.9)	710 (65.2)	<0.001*	1,512 (68.4)	<0.001*
Antidepressants	11,486 (56.1)	430 (39.5)	<0.001*	1,032 (46.7)	<0.001*
Anxiolytics	10,560 (51.6)	429 (39.4)	<0.001*	849 (38.4)	<0.001*
Mood stabilizers	8,504 (41.5)	398 (36.5)	0.001*	826 (37.4)	<0.001*
Number of unique psychiatric agents received,e mean ± SD (median)	3.4±2.7 (3.0)	2.9±2.8 (2.0)	<0.001*	3.2±2.5 (3.0)	0.001*
Psychiatric polypharmacy present,f n (%)	8,932 (43.6)	383 (35.2)	<0.001*	884 (40.0)	0.001*

Notes:

* P-value <0.05 (versus OAP).

a P-value refers to a comparison with the OAP reference group, calculated using the Pearson chi-squared test (categorical variables) and Wilcoxon rank-sum test (continuous variables).

b The number of unique 4-digit ICD-9-CM diagnoses observed (including schizophrenia, psychosis, and substance use-related diagnoses).

c The denominator for the proportion of patients with a PDC <80% or a PDC ≥80% is the number of patients with a PDC >0.

d AP polypharmacy is defined as having overlapping coverage of ≥2 unique AP agents for at least 60 consecutive days with no gaps larger than 7 days.

e Includes mood stabilizers, anxiolytics, antidepressants, and AP.

f Psychiatric polypharmacy is defined as having overlapping coverage of ≥1 AP agent and ≥1 anxiolytic, antidepressant, or mood stabilizer for at least 60 consecutive days with no gaps larger than 7 days.

Abbreviations: AP, antipsychotics; Quan-CCI, Quan-Charlson comorbidity index; FGA, first-generation antipsychotics; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; LAI, long-acting injectable therapies; OAP, oral antipsychotics; PDC, proportion of days covered; SD, standard deviation; SGA, second-generation antipsychotics.

Table 2 Treatment patterns observed during the 12-month follow-up period

Characteristic	OAP (A)	FGA-LAI (B)		SGA-LAI (C)
	(N=20,478)	(N=1,089)	P-valuea (A) vs (B)	(N=2,209)	P-valuea (A) vs (C)
Number of AP prescription fills, mean ± SD (median)	16.2±13.6 (13.0)	16.8±13.6 (13.0)	0.018*	15.1±11.3 (13.0)	0.170
Number of prescription fills for the index drug, mean ± SD (median)	8.3±7.1 (7.0)	7.7±5.0 (7.0)	0.293	9.1±5.9 (8.0)	<0.001*
Number of unique AP agents received, mean ± SD (median)	2.2±1.2 (2.0)	2.2±1.2 (2.0)	0.261	2.1±1.2 (2.0)	<0.001*
PDC for index medication (%), mean ± SD	49.8±30.2 (44.1)	48.2±27.1 (45.2)	0.160	52.1±29.7 (49.3)	0.007*
Psychiatric medication use during follow-up (excluding index drug), n (%)	19,449 (95.0)	883 (81.1)	<0.001*	1,771 (80.2)	<0.001*
AP use	13,832 (67.5)	733 (67.3)	0.871	1,394 (63.1)	<0.001*
FGA oral and short-term injectable APs	4,441 (21.7)	451 (41.4)	<0.001*	393 (17.8)	<0.001*
SGA oral and short-term injectable APs	11,037 (53.9)	515 (47.3)	<0.001*	1,207 (54.6)	0.505
FGA-LAI	1,924 (9.4)	59 (5.4)	<0.001*	115 (5.2)	<0.001*
SGA-LAI	1,870 (9.1)	69 (6.3)	0.002*	143 (6.5)	<0.001*
Adjunctive therapy use	18,391 (89.8)	757 (69.5)	<0.001*	1,519 (68.8)	<0.001*
Anxiolytics	12,262 (59.9)	473 (43.4)	<0.001*	851 (38.5)	<0.001*
Mood stabilizers	10,754 (52.5)	419 (38.5)	<0.001*	830 (37.6)	<0.001*
Antidepressants	14,137 (69.0)	475 (43.6)	<0.001*	1,056 (47.8)	<0.001*
AP polypharmacy present,b n (%)	6,717 (32.8)	392 (36.0)	0.029*	585 (26.5)	<0.001*
Psychiatric polypharmacy present,c n (%)	14,373 (70.2)	546 (50.1)	<0.001*	1,033 (46.8)	<0.001*

Notes:

* P-value <0.05 (versus OAP).

a P-value refers to a comparison with the OAP reference group, calculated using the Pearson chi-squared test (categorical variables) and Wilcoxon rank-sum test (continuous variables).

b AP polypharmacy is defined as having overlapping coverage of ≥2 unique AP agents for at least 60 consecutive days with no gaps larger than 7 days.

c Psychiatric polypharmacy is defined as having overlapping coverage of ≥1 AP agent and ≥1 anxiolytic, antidepressant, or mood stabilizer for at least 60 consecutive days with no gaps larger than 7 days.

Abbreviations: AP, antipsychotics; FGA, first-generation antipsychotics; LAI, long-acting injectable therapies; OAP, oral antipsychotics; PDC, proportion of days covered; SGA, second-generation antipsychotics; SD, standard deviation.

Figure 2 Observed adherence (PDC ≥80%) on index treatment during the 12-month follow-up period.

Abbreviations: FGA-LAI, first-generation long-acting injectable therapies; OAP, oral antipsychotics; PDC, proportion of days covered; SGA-LAI, second-generation long-acting injectable therapies.

Figure 3 Observed persistence (no gap ≥30 days, ≥60 days, or ≥90 days) on index treatment during the 12-month follow-up period.

Abbreviations: FGA-LAI, first-generation long-acting injectable therapies; OAP, oral antipsychotic; SGA-LAI, second-generation long-acting injectable therapies.

Figure 4 Multivariable comparison of adherence and persistence outcomes during the 12-month follow-up period.

Note: *P-value <0.05 (versus OAP).
Abbreviations: CI, confidence interval; FGA-LAI, first-generation long-acting injectable therapies; OAP, oral antipsychotics; PDC, proportion of days covered; SGA-LAI, second-generation long-acting injectable therapies.