Attitudes toward long-acting injectable antipsychotics among patients with schizophrenia in Japan

Figures & data

Figure 1 Responses of patients and their psychiatrists regarding the appropriateness of LAI treatment among patients taking oral antipsychotic medication only.

Notes: The box shaded with vertical lines represents type A discrepancy (patients evaluated the appropriateness of LAI treatment higher than their referring psychiatrists). On the other hand, the box shaded with horizontal lines represents type B discrepancy (patients evaluated the appropriateness of LAI treatment lower than their referring psychiatrists).
Abbreviation: LAI, long-acting injectable antipsychotic.

Table 1 Patient attitudes toward LAIs according to the current formulation among patients with schizophrenia in Japan

Do you believe…		Oral antipsychotics		LAIs		χ^2
		Yes		Yes		P-value
Q1	… that depot have milder side effects than oral treatment?	18.0%	(23/128)	76.0%	(19/25)	<0.001
Q2	… that by depot you are better protected against relapse?	32.8%	(42/128)	79.2%	(19/24)	<0.001
Q3	… that depot offer better efficacy than oral treatment?	43.0%	(55/128)	79.2%	(19/24)	0.001
Q4	… that depot limit the autonomy of the patient?	38.6%	(49/127)	28.0%	(7/25)	0.316
Q5	… that depot are very painful?	58.6%	(75/128)	29.2%	(7/24)	0.008
Q6	… that antipsychotic doses are lower with depot treatment than with oral drugs?	51.6%	(66/128)	72.0%	(18/25)	0.060
Q7	… that depot are more expensive than oral treatment?	66.4%	(85/128)	32.0%	(8/25)	0.001
Q8	… that depot offer a reduced range of antipsychotic choices?	57.8%	(74/128)	70.8%	(17/24)	0.232

Abbreviation: LAIs, long-acting injectable antipsychotics.

Table 2 Clinical and demographic characteristics according to current formulation

	Oral antipsychotics	LAIs	t-test
	(mean ± SD)	(mean ± SD)	P-value
Age (years)	43.3±13.4	49.1±11.9	0.034
Duration of illness (years)	16.1±10.1	22.1±8.4	0.004
Duration of education (years)	11.9±2.1	11.5±1.5	0.337
CGI-S	4.0±1.1	4.4±0.9	0.137
DIEPSS total score	2.4±3.9	4.3±3.8	0.095
GAF	57.7±14.6	53.6±12.2	0.129
Total CP equivalent dose (mg)	504±376	771±478	0.008
CP equivalent dose of oral administration (mg)	504±376	505±488	0.995
SF-36v2^® score
Physical component summary	39.8±16.1	35.1±22.7	0.446
Mental component summary	45.0±10.9	48.5±13.8	0.272
Rosenberg Self-Esteem Scale
Positive self-esteem	12.4±3.8	13.0±3.7	0.509
Negative self-esteem	11.8±3.6	11.4±3.7	0.640
	%	%	χ^2
Gender (proportion of males)	43.1 (56/130)	44.8 (13/29)	0.863

Abbreviations: CGI-S, Clinical Global Impressions-Severity of Illness scale; CP, chlorpromazine; DIEPSS, Drug-Induced Extrapyramidal Symptoms Scale; GAF, Global Assessment of Functioning; LAIs, long-acting injectable antipsychotics; SF-36v2^®, 36-Item Short-Form Health Survey version 2.

Table 3 Factors associated with acceptance of LAIs (response that these drugs are appropriate for one’s own case) among patients treated with oral antipsychotics only

	B	Standard error	Wald value	P-value	Odds ratio
Q2	1.36	0.61	4.91	0.027	3.89 (1.17–12.91)

Notes: After adjusting for confounding factors (age, gender, amount of education, duration of illness, CGI-S score, GAF score, and DIEPSS score), we performed a multivariate logistic regression analysis with a forward selection method to assess the influence of attitudes on acceptance of LAIs among patients treated with oral antipsychotics only.

Abbreviations: CGI-S, Clinical Global Impressions-Severity of Illness scale; DIEPSS, Drug-Induced Extrapyramidal Symptoms Scale; GAF, Global Assessment of Functioning; LAIs, long-acting injectable antipsychotics.

Table 4 Factors associated with doctor–patient discrepancy regarding the appropriateness of long-acting injectable antipsychotics treatment among patients treated with oral antipsychotics only

	B	Standard error	Wald value	P-value	Odds ratio
Type A discrepancy
Q5	−2.09	1.11	3.52	0.06	0.12 (0.01–1.10)
Type B discrepancy
CGI-S	0.60	0.22	7.22	0.01	1.82 (1.18–2.82)
Q2	−1.79	0.73	5.96	0.01	0.17 (0.04–0.70)
Q5	1.63	0.65	6.25	0.01	5.10 (1.42–18.31)
Q8	−1.25	0.59	4.56	0.03	0.29 (0.09–0.90)

Notes: After adjusting for confounding factors (age, gender, amount of education, duration of illness, CGI-S score, GAF score, and DIEPSS score), we performed a multivariate logistic regression analysis with a forward selection method to assess the influence of attitudes (Q1–Q8) on discrepancy between patients’ and psychiatrists’ responses on the appropriateness of LAIs treatment. Type A discrepancy: patients evaluated the appropriateness of LAI treatment higher than their referring psychiatrists. Type B discrepancy: patients evaluated the appropriateness of LAI treatment lower than their referring psychiatrists.

Abbreviations: CGI-S, Clinical Global Impressions-Severity of Illness scale; DIEPSS, Drug-Induced Extrapyramidal Symptoms Scale; GAF, Global Assessment of Functioning; LAIs, long-acting injectable antipsychotics.