Participants and Procedure
This study was conducted in Ningxiang County of Hunan province from November 2015 to January 2016. Our sample was recruited from the “Central Government Support for the Local Management and Treatment of Severe Mental Illnesses project”, also named the “686 program”, which is China's largest demonstration project for mental health services that seeks to integrate hospital and community services for serious mental illness (34, 35).
A one-stage cluster-sampling method was used to recruit participants from the 686 Program. First, three Towns and 1 Xiang (an administrative unit similar to a town but with lower socio-economic development) were randomly selected from Ningxiang County, and then followed by whole sampling within each Town/Xiang, leading to a total sampling frame of 55 representative communities/villages. A local primary care physician within each community/village assisted in identifying eligible participants based on a list of clients registered in the 686 Program. Eligibility criteria for primary family caregivers included: 1) a PLWS who is a family member who is registered in the 686 Program; 2) the PLWS meets criteria of the Chinese Classification of Mental Disorders-3 (CCMD-3) or the International Classification of Diseases-10 (ICD-10) for schizophrenia; 3) the primary caregiver is living with the PLWS and is responsible for caregiving; 4) the primary caregiver is older than 16 years of age ; 5) the primary caregiver is neither illiterate nor seriously sick and thus able to understand and communicate. A total of 352 primary family caregivers of PLWS were identified in the final sample.
The community/village primary care physician visited each study household with a member of the research team to obtain informed consent from the caregiver and PLWS. Both then completed a series of questionnaires (see measures below) in face-to-face interviews. All participants were reimbursed with small gifts equivalent to RMB ¥ 10 (approximately USD$2) in return for their participation. Details of the subject recruitment process have been described elsewhere (36, 37).
Of the 352 participants approached, 327 participated in the interview (response rate: 93%). No significant differences in socio-demographic background were observed between those who did or did not agree to participate based on gender, age, marital status, and education (results not shown here). In the current study, only parents (n = 151) and spouses (n = 113) were included in the analyses, resulting in a final sample of 264.
Measures
Socio-demographic information. Demographic information of both the PLWS and the primary caregiver was collected on a questionnaire designed for this study, which included gender, age, marital status, occupation, education, family financial status, and kinship between PLWS and the primary caregiver. For the primary caregivers, we also asked if there were any co-caregivers, dependents, physical illnesses, and how care had been provided for the PLWS.
PLWS functioning. The PLWS functioning was assessed using the Global Assessment of Function scale (GAF) (38) which assessed the person’s overall social, occupational and psychological functioning in the past month from 1 (lowest) to 100 (highest). On the GAF, examples are provided for each ten-point interval. The GAF is an axis of the DSM-IV and is a reliable and valid measure of psychiatric functioning (38).
Caregiving activities. Concrete caregiving activities were assessed by four “Yes-No” questions asking if the respondent was involved with the following four aspects of caregiving activities for the PLWS: daily activities, medication management, hospital visits, and financial help. Responses of “no” were scored as 0, and “yes” as 1, and then followed by asking how often the respondent was involved with each caregiving activity, ranging from “occasionally” (scored as 1) to “always” (scored as 4). Detailed information about the questions and optional answers can be found in the S1 Appendix.
Objective burden. Objective burden was assessed using the Family Burden Interview Schedule (FBIS) (39) classified into six categories: financial burden, disruption of routine family activities, family leisure, family interactions, and effect on physical and mental health of others. The scale consists of 24 items rated on a 3-point Likert scale from 0 (no burden) to 2 (serious burden). The total score ranges from 0 to 48 with higher scores showing higher family burden. In the present study, the Chinese version of FBIS showed acceptable internal consistency with a Cronbach’s α of 0.86 for the total scale and ranged from 0.63 to 0.86 for the subscales.
Subjective burden. Subjective burden was assessed using the Zarit Burden Interview (ZBI) (40). The ZBI consists of 22 items scored on a 5-point Likert scale from 0 (never) to 4 (nearly always), except for the final item on global burden, rated from 0 (not at all) to 4 (extremely). The total score ranges from 0 to 88 with higher scores indicating higher perceived burden (41, 42). In the present study, the Chinese version of ZBI showed acceptable internal consistency with a Cronbach’s α coefficient of 0.89.
Caregiver depression. Caregiver depression was measured using the 9-item Patient Health Questionnaire (PHQ-9) (43), which consists of 9 items scored in 4-point Likert scale from 0 (not at all) to 3 (nearly every day). The total score ranges from 0 to 27, with higher scores implying more depressive symptoms, and a cut-off point of 10 differentiating depression and non-depression (44, 45). In the present study, the Chinese version of the PHQ-9 demonstrated good internal consistency with a Cronbach’s α coefficient of 0.89.
Caregiver anxiety. Caregiver anxiety was measured by the 7-item Generalized Anxiety Disorder Scale (GAD-7) (46) which detects the primary caregiver’s anxiety symptoms during the past two weeks. Each item is rated on a 4-point Likert scale from 0 (not at all) to 3 (nearly every day). The total score ranges from 0 to 21, with a cut-off point of 10 differentiating anxiety and non-anxiety (47). The Chinese version of the GAD-7 demonstrated good internal consistency in the current study with a Cronbach’s α coefficient of 0.91.
Caregiving rewarding feelings. Positive feelings about caregiver were assessed using the caregiving rewarding feelings (CRF) scale which was designed for this study. The detailed development and validation process of the CRF has been described elsewhere(48). It consists of 12 items asking about a range of possible rewarding feelings that caregivers may have during caregiving. Each “yes” response was scored 1 and “no” responses 0, with total scores ranging from 0 to 12; higher scores indicate more positive feelings in caregiving. The CRF showed acceptable reliability in the current study with a Cronbach's alpha of 0.77.
Caregiver perceived family functioning. Caregiver perceived family functioning was assessed using the Family Adaptation, Partnership, Growth, Affection and Resolve Index scale (APGAR)(49). It consists of 5 items scored in 3-point Likert scale from 0 (hardly ever) to 2 (almost always). The total score ranges from 0 to 10 with higher scores indicating higher satisfaction with family functioning. In the present study, the Chinese version of APGAR showed acceptable internal consistency with a Cronbach’s α coefficient of 0.91.
Statistical Analysis
Data were analyzed using STATA software version 15.0. Data were examined missing values, influential values and outliers, skewness, and kurtosis. Frequencies and percentages were displayed for categorical variables, and means with standard deviations or medians with interquartile ranges (IQR) displayed for continuous variables. Group differences for continuous variables were tested using independent t-tests for normally distributed data or a Mann-Whitney U test for non-normally distributed data. Group differences for categorical variables were tested using Pearson’s chi-square tests. Both univariate and multivariate linear regression were conducted to determine associations and predictors.
Ethical Considerations
This study was approved by the Ethics Review Committee of the Xiangya School of Public Health of Central South University in China. The interviewed participants were informed verbally and in writing of the study’s purpose, their right to refuse to participate, and the voluntary nature of their participation. All participants provided written informed consent before the interviews.