Participants
The participants were community-dwelling people with schizophrenia living in the urban areas of Yokohama and Kawasaki in Kanagawa, Japan. The inclusion criteria for the participants were as follows: (1) diagnosed with schizophrenia according to the International Classification of Diseases-10; (2) living in the community; (3) aged 18–64 years; and (4) discharged for at least one and a half years from a psychiatric hospital. The participants were recruited from among the users of a local activity support center in Japan because people with schizophrenia already living in the community and those who have just been discharged from psychiatric hospitals are encouraged to use local activity support centers to reintegrate into the community [
20].
The researchers sent the questionnaire and an informed consent letter to each local activity support center via mail. Each participant was asked to complete a self-administered, anonymous questionnaire voluntarily between August 1 and October 31, 2014. Before the start of the study, written informed consent for participation was obtained from the Legal Authorized Representative (LAR) guardians of the patients with schizophrenia. Moreover, informed consent was obtained from all the individual participants included in the study.
Measures
The original CIM was developed in Canada for people with traumatic brain injuries [
15], though the contents are applicable to all people with disabilities who face challenges in their integration into community life [
12]. McColl et al. developed a theoretical model of community integration from the perspective of people with disabilities, and the CIM’s definition of community integration focuses on the subjective experiences of integration rather than on its observable components. The CIM is based on this client-centered model [
15]. The CIM consists of 10 items with no definite cut-off score for community integration. A previous study reported a mean CIM score of 37.0 (SD = 8.6) for people with schizophrenia or bipolar disorder who use public mental health services [
9]. The total number of questionnaire items in the present study was 48, which addressed the following topics: demographic characteristics 12 items, social network 6 items, self-esteem 10 items, and loneliness 20 items. The Japanese version of the CIM included the following questions: “I feel like a part of this community, like I belong here;” “I can be independent in this community;” and “I have something to do in this community during the main part of my day that is useful and productive.” Responses were coded as follows: 5 = always agree, 4 = sometimes agree, 3 = neutral, 2 = sometimes disagree, and 1 = always disagree. The total CIM score ranged from 10.0 to 50.0, with higher scores indicating higher degrees of community integration. The reliability of the original CIM has been established (Cronbach’s alpha = 0.87), and its validity has been tested using a correlation with the Interpersonal Support Evaluation List.
The demographic characteristics of the participants in this study included basic characteristics such as age, sex, living status, household membership, marital status, educational status, employment status, budget, and items pertaining to features of schizophrenia, such as the cumulative number of years of psychiatric hospitalization.
Three other scales were administered to assess the concurrent validity of the Japanese version of the CIM.
Social networks were measured using the Japanese version of the Lubben Social Network Scale-Abbreviated (LSNS-6) [
21]. The LSNS-6 assesses the concept of social networks, including their functions, such as social support [
22]; this concept has been examined previously [
15]. The scale consists of six items. Responses to the scale are assessed using a 6-point scale. The total score ranges from 0.0 to 30.0, with high scores indicating a good social network. A total score below 12.0 on the LSNS-6 identifies people at risk of social isolation. The scale’s reliability has been established with a Cronbach’s alpha of 0.82, and its validity was tested via correlation with the Zung Self-Rating Depression Scale, a social support questionnaire, and the risk of suicide. The authors hypothesized that the LSNS-6 would correlate with the Japanese version of the CIM in terms of support.
Self-esteem is defined as one’s attitude toward one’s own ability and strength [
23]. It was measured using the Japanese version of the Rosenberg Self-Esteem scale (RSE) [
24], which consists of 10 items. The RSE is the most widely used measure of self-esteem, and its psychometric validity has been confirmed in many different population samples, including patients with schizophrenia. Responses to the scale are assessed using a 5-point Likert scale. The total possible score ranges from 10.0 to 50.0, with higher scores indicating greater self-esteem. The scale’s reliability has been established with a Cronbach’s alpha of 0.81, and its validity was tested via correlation with the Brief Core Schema Scale and the Automatic Thoughts Questionnaire-Revised. McColl et al. [
15] reported that participation in activities or self-determination is related to one’s perception of one’s own ability or strength. Based on the original study, we considered that the RSE would relate to the Japanese version of the CIM in terms of independent living and occupation.
Loneliness was determined using the Japanese version of the UCLA Loneliness Scale Version 3 (UCLALS) [
25]. The UCLALS consists of 20 items and includes questions such as “How often do you feel left out?” “How often do you feel the lack of companionship?” and “How often do you feel isolated from others?” Each item is answered on a 4-point Likert scale. The total UCLALS score ranges from 20.0 to 80.0, with higher scores indicating higher degrees of loneliness. All 20 items are highly inter-correlated in the Japanese version (Cronbach’s alpha = 0.92), and the validity of the scale was tested via its correlation with the Geriatric Depression Scale-Short Version-Japanese. Loneliness is the unpleasant experience that occurs when a person’s network of social relations is either quantitatively or qualitatively deficient in some important ways [
26]. It was hypothesized that UCLALS would correlate with the Japanese version of the CIM in terms of assimilation and support.
Statistical analysis
Descriptive statistics were used to describe the participants’ demographic characteristics. Several statistical tests were conducted to examine the psychometric properties of the Japanese version of the CIM.
Item analysis included assessing the percentage of missing values, skewness, kurtosis, good-poor (GP) analysis, and the item-total (IT) correlation analysis. These analyses were conducted to show the normality of the variables for the application of parametric analysis and to confirm that the items were appropriate. In the GP analysis, the total points were selected, an average for each separate item was calculated, and the top 25% was classified as the “good” group while the bottom 25% was classified as the “poor” group.
Exploratory factor analysis (EFA) using maximum-likelihood estimation was conducted to determine the number of items and the nature of the underlying factors in the Japanese version of the CIM. Factor loadings equal to or greater than 0.4 were considered acceptable [
27].
Internal consistency was tested using Cronbach’s alpha coefficient to determine the reliability of the instrument. A Cronbach’s alpha coefficient greater than 0.70 was considered acceptable [
28].
The construct validity was examined using confirmatory factor analysis (CFA) to assess the model fitness. Various fit indices were used to assess the fit of the model to the data: the goodness of fit index (GFI), the adjusted goodness of fit index (AGFI), the comparative fit index (CFI), and the root mean square error of approximation (RMSEA). GFI, AGFI, and the CFI values greater than 0.90 were considered acceptable [
29], and RMSEA values ranging from 0.08 to 0.10 were considered indicative of a mediocre fit [
30].
Concurrent validity was assessed by estimating Pearson’s correlation coefficients between the Japanese version of the CIM and external criteria, including demographic characteristics and the LSNS-6, RSE, and UCLALS scores. Student’s t test and analysis of variance (ANOVA) were conducted to assess the relationship between demographic characteristics. If the distribution of variance showed homoscedasticity according to the Levene test, Tukey’s test was performed for multiple comparisons. All analyses were conducted using IBM® SPSS for Windows version 22.0 and Amos version 20.0. Statistical significance was set at p < 0.05.