Previously titled: Development and psychometric testing of the Thai impact and burden of care scale for caregivers of persons with schizophrenia and co-occurring methamphetamine use

Objective: The objective of the present study was to develop the Thai version of the Impact and Burden of Care Scale for Caregivers of Persons with Schizophrenia and Co-occurring Methamphetamine Use (TIBSCSM) and test its psychometric properties. Methods: This instrument development research subjects were 142 caregivers of persons with schizophrenia and co-occurring methamphetamine use. Sample size adequacy was tested by Kaiser–Meyer–Olkin (KMO), and Bartlett's test of sphericity tested the adequacy of the item correlation matrix. The second-order confirmatory factor analysis (CFA) was used to test the theoretical model. Results The 32-item TIBSCSM showed convergent validity correlations with two quality-of-life measures. Additionally, KMO=0.9, Bartlett’s Test of Sphericity χ2=5248.5, df=496, p<0.001, CVI =1, and internal consistency reliability was high (α=0.9). The CFA has shown that the findings are supported by the theoretical models (χ2=325.2, df=287, p<0.001, RMSEA=0.0, CFI =0.9). Conclusion: The TIBSCSM scale has potential benefits for psychiatric nurses and psychiatric care teams to measure the impact and care burden of caregivers of persons with schizophrenia and methamphetamine use in the areas of nursing, research, education, and clinical determination. The test results suggested that The TIBSCSM scale has potential benefits for psychiatric and mental health care team to assess the impact and burden care of schizophrenic caregiver for both research and clinical purposes, especially during the COVID-19 pandemic for Open Peer Review Approval Status 1 2 version 2 (revision) 17 Feb 2022 view view version 1 17 Jun 2021 view view Virya Koy , Chulalongkorn University, Bangkok, Thailand 1. Joko Gunawan , Belitung Raya Foundation, Belitung, Indonesia 2. Any reports and responses or comments on the article can be found at the end of the article. Page 1 of 19 F1000Research 2022, 10:484 Last updated: 24 FEB 2022


Introduction
Schizophrenia with co-occurring methamphetamine use is an incapacitating and complex psychiatric illness with either stage, phase, personal factors, and continuous evolution, resulting in impaired physical and psychological health status and social problems. Additionally, it impacts on caregivers' role and functioning that add to the burden of care and economic consequences. [1][2][3] Moreover, care burden can lead to a low quality of life (QOL), particularly when suffering significant burdens, resulting in role confusion, poor caring performance, psychosomatic problems, anxiety, stress, and depressive symptoms. The negative emotional experience of caregivers may lead to low performance of caring and have crucial adverse effects on medication compliance, continuity, and a good understanding of the care and social support. 1,4 The caregivers work out ways to take care of persons with schizophrenia and methamphetamine misuse with severe psychotic symptoms to the best of their ability. They try to decrease warning signs such as aggressive and violent behaviors as soon as possible. The caregiver tries to give the reasons, call their name, suggest cool water to drink, or shower and express their love and care by speaking gently. They also deal with hardships in caring for patients, which happen to their belongings, other people, and themselves due to harm resulting from psychotic symptoms. During the relapse phase, caregivers work hard with relapses using many ways to prevent injury, set a safe environment, continue medication adherence and soothe their relatives' psychological state. Additionally, the caregiver tries to pull their relatives back to a normal state as much as possible by encouraging their relatives' memories and ability to perform activities of daily living.
Numerous studies of evidence-based practice have illustrated that a lack of primary caregiver involvement in treatment planning is related to the treatment adherence issue. Consequently, evaluating the caregivers' impact and care burden is of considerable relevance both for caregivers and indirectly for the quality of life of persons with schizophrenia with co-occurring methamphetamine use.
The caregivers' impact, coping strategies, stress, burden, anxiety, caregiving, and views on the grounds and magnitudes of psychiatric illnesses and co-occurring substance abuse require significant attention. Moreover, currently, the development of psychosocial interventions for caregivers is also a considerable concern. There is an essential need for interventions to enhance caregivers' emotional health and performance programs delivered by nurses and healthcare teams. 5 Based on this, it is necessary to develop good psychometric properties to assess the impact and burden of caregivers of persons with schizophrenia with co-occurring methamphetamine use.
Although studies have been conducted on specific issues in caregiving, little has been done to explore the impact and burden among caregivers of persons with schizophrenia. Furthermore, no impact and burden scale has been developed explicitly for use with primary caregivers based on the caregivers' experience. 6 Being anchored in an exact conceptual method is needed. Development of a measure of caregivers' impact and burden could help elucidate the biological and psychological aspects of caregiving, including quality of life, and preserving caregivers' well-being and aptitude for care. This can help multidisciplinary treatment teams to develop new care strategies for this population. The Thai version of the Impact and Burden of Care Scale for Caregivers of Persons with Schizophrenia and Co-occurring Methamphetamine Use (TIBSCSM) was developed and assess the impact on caregivers caring for patients with schizophrenia. The objective of this study was to develop a scale and test its psychometric properties.

Subjects
Data were collected from the caregivers of people with schizophrenia with co-occurring methamphetamine use at psychiatric hospitals. The inclusion criteria were: (1) having a family member with a diagnosis of schizophrenia or schizoaffective disorder, according to the DSM-V criteria; 7 (2) being identified by persons with schizophrenia and co-occurring methamphetamine use as the primary caregiver; and (3) being 18 years of age or older.

REVISED Amendments from Version 1
The major differences between this version of your article and the previously published version. 1. Change the title of this paper as the reviewer's comments 2. Change the objective of the study 3. Add CVI value 4. Add Implication for nursing and research Any further responses from the reviewers can be found at the end of the article Procedure Over four weeks, identified inpatients, who met the criteria of a diagnosis of schizophrenia with co-occurring methamphetamine use and were 18-60 years old, were selected. A psychiatric nurse asked them to name their primary caregiver. The researcher asked them if we could contact the primary caregiver. When they agreed, and when the caregiver met the inclusion criteria, the self-report scale was collected and completed by the researcher teams' caregivers or interviews.

Ethical approval
Ethical approval for the study was obtained from the Ethics Review Committee for Research Involving Human Research Participants (COA No. 284/2560). The scopes, risks, and benefits of this study for the subjects were explained. Before data collection, written consent was obtained directly from the PCPSs Participation was voluntary, and participant anonymity and confidentiality were guaranteed.

Data collection
The data collected included the following: 1. Demographic characteristics of the primary caregivers.

TIBSCSM:
The self-administered scale that the caregivers completed.

Scale development
Development of the TIBSCSM occurred in two phases: a) qualitative and b) quantitative. Item generation occurred during the qualitative phase, and item reduction and the validation process happened during the quantitative phase. 8 The two steps involved collecting data from different subjects.
Item generation: a qualitative approach Item generation occurred in two steps. First, the content was derived from the questionnaire from face-to-face, semistructured interviews performed by the researcher. Briefly, discussions addressed the impact and burden of care based on caregiver stress theory, a middle-range theory. Second, the objective was to predict caregiver stress and its outcomes from demographic characteristics, an objective burden in caregiving, stressful life events, social support, and social roles. 9 The determined wording of question stems and the range of response options until saturation by 30 caregivers' interviews. The researcher performed content analysis. Third, the researcher identifies 32 questions from this interview process. These items were answered using a five-point Likert scale, defined as: 1: never/not at all; 2: rarely/a little; 3: sometimes/somewhat; 4: often/a lot; and 5: always/very much." 30 caregivers were requested to remark on any part of the scale (i.e., content, wording, response choices) that they considered inappropriate or merited improvement. Ambiguous items and those that were misinterpreted or infrequently answered were withdrawn or rephrased, leading to a preliminary scale that contained 32 items. Lastly, preliminary interviews were conducted with the caregivers to ensure that the scale was a true reflection of the caregivers' understanding and confirmed content validity. The second round of interviews with caregivers guaranteed its face validity.
Item reduction and validation of the TIBSCSM: a quantitative approach The item reduction process comes from the results of statistical analyses and the steering committee's expertise. Item response theory and classical test theory conduct by Statistical approaches. 10 Both metrological properties and their impact on the final scale's content, taking into account the items' meanings, were discussed and then removed items. The researcher retained items to produce the final version of the TIBSCSM in more robust and psychometrically sound solutions. The researcher tested for construct validity, reliability, and some aspects of external validity in the last version. Convergent validity was evaluated by examining correlations between the TIBSCSM and two measures of caregivers' quality of life: the Thai version of the Schizophrenia Caregiver Quality of Life Questionnaire (S-CGQoL-Thai Scale) and the Thai version of the World Health Organization Brief Quality of Life Scale (WHOQOL-BREF-THAI). Construct validity defines the construct to be assessed by the scale and measures its construct's internal structure and the theoretical relationship of its item and subscale scores. It was evaluated using principal component factor analyses with varimax rotation 11 to define the number of independent items and dimensions.

Sample characteristics
The mean age of the 142 participants was 47.1 years old (SD = 8.4). They were predominantly female (73.9%), married (63.4%), and about half had completed at least a bachelor's degree (50.7%) and worked in agriculture (57.8%). Additionally, almost all of them (83.1%) had insufficient income, were healthy (61%), and had been the caregiver for more than five years (48%). Regarding medical history, about one-third of them (35.1%) used universal healthcare coverage, and more than half of them had no medical illness (61%) ( Table 1).

Validity and reliability
The TIBSCSM with 32 items showed content validity index = 1. Regarding convergent validity, the TIBSCSM had correlations with the S-CGQoL-Thai Scale and the WHOQOL-BREF-THAI. Factor analysis showed good construct validity, Kaiser-Meyer-Olkin (KMO) = 0.9, Bartlett's Test of Sphericity, χ2 = 5248.5, df = 496, p < 0.001. For the content validity, the scale show CVI = 1 and S-CVI = 0.86. Cronbach's alpha showed high internal consistency reliability (α=0.9). The corrected item total correlation ranged 0.5-0.8. The total variance explained was 64.9%, which is excellent. Also, the extract construct of factor analysis was the following: physical function, self-esteem, role and social enjoyment, and relationship satisfaction ( Figure 1).
Correlation testing between the 32 items found that the correlation coefficient of all 32 questions was in the range 0.3-0.8, and the correlation coefficient of the internal items of each construct were medium to high in the positive correlation with statistical significance at 0.05 (Table 2, Figure 2).
The first-order factors loading = 0.5-0.8 and the variance of first-order factors loading were explained by a latent variable of second-order factors of the four constructs ranking 66.3% -74.0%. Besides, factor loading of TIBSCSM, factor score, and R2 range between = 0.6-0.8, of TIBSCSM.

Discussion
The findings indicate that the TIBSCSM is psychometrically sound and well-suited for assessing caregivers' impact and burden of care for persons with schizophrenia and methamphetamine misuse. We discuss the psychometric properties testing in the following sections.
First, the internal structure, supported by high internal consistency, confirmed that the TIBSCSM measures a multidimensional concept. Cronbach's alpha was 0.9. This means strong correlations between items within each domain of the scale and between all items in the scale. [12][13] Figure 2. Second-order of Impact and burden care model. Second, the KMO test and Bartlett test of sphericity showed the adequacy of the item correlation matrix. This reflects that the sample size was appropriate. 11 Third, the components' analysis showed that the factor loadings were 0.6-0.8, which shows that the items had very high effects on the factors. The criteria for choosing an item is that the factor loading should be greater than 0.5. All questions and questions had a value of 0.5-0.8. 11 Additionally, the construct validity of the test was verified by factor analysis. Four components could be extracted together with the results from the scree plot graph. The parts of the four factors explained 64.9% of the variance, which shows that the 32 questions substantially explained variations in the levels of the impact and burden of care in Thai primary caregivers of people with schizophrenia who also use methamphetamine, reliably and consistently with the theory of the Caregiver Stress model. Similar to results from other empirical studies, 14 the findings illustrate that the predictors of family caregivers' impact and burden care were a) physical and psychological well-being, b) dependence in performing activities of daily living, c) caring quality, d) burden and everyday life, and e) caring performance.
Additionally, the TIBSCSM, like the theory of caregiver stress, is based on the Roy Adaptation Model that identifies the caregiver's response, perceptions, and adaptations to the stress and burden they experience in terms of their social role and how they reduce and cope with stress. Additionally, it was found that caring for people with schizophrenia often causes caregivers to perceive a high burden of care, lose energy, have anxiety and depression, and have worse overall mental health. There is an increased risk of emotional problems such as guilt, anger, and dissatisfaction. Research has found that most caregivers have emotional stress problems. 14 Besides, persistent requests for more help cause caregivers to become frustrated. Sometimes the emotions cannot be suppressed. Intense and negative emotions may occur.
Moreover, it has been found that many caregivers with negative cognitive processes and the inability to provide quality care may experience feelings of failure, resulting in negative perceptions of various aspects, such as having no time for family or other activities or inability to care for people with schizophrenia fully. Additionally, consistent with the caregivers' stress theory, 9 effects on the caregiver include reduced physical function, feelings of low self-worth, and reduced role enjoyment and marital satisfaction, which directly affect the carers' lives. Individual perceptions of their status in life fall under the context of the culture and system definition in a society that lives and relates to goals, expectations, society standards, and other related things. They covered physical health and mental state, degree of independence, social relations beliefs, and relationships that need to be an environment. Besides, goal burden is the most influential factor for caregivers' stress, such as caring for hours at a time or care that extends for years. This is consistent with the personal data of more than half of the sample who have taken care of patients for more than ten years. If caregivers perceive high levels of stress, they will make ineffective responses. Additionally, the care burden may lead to depression as a direct result of the stressor may affect stress adjustment.
Besides, these responsibilities may affect other aspects of the caregiver's life, such as interpersonal relationships. Financial conditions are defined as contextual stimuli. Social support, social roles, and life events that cause stress are life-changing conditions that challenge individuals and result in suffering. In the study sample, 83.10% of participants had incomes that were insufficient to cover their living expenses, and 45.45% had stress levels at 51-75 points.
Social support allows carers to see that they are being cared for. A high level of social support will increase the ability to cope with the burden effects of care. Additionally, social roles are defined as the caregiver's relationship to the patient, such as being a parent or child. Most of the sample had one of these two roles, with social functions allowing caregivers to express their feelings and release their emotions, making them more likely to deal with the images and effects of care. The sample had an average age of 47 years, which can change the perspective of each person. Older caregivers have more life experiences and more opportunities to use and adjust their coping skills. [15][16][17][18] Conclusion In conclusion, in the present paper, the findings suggested that the TIBSCSM scale has potential benefits for psychiatric and mental health care teams to assess the impact and burden of caregivers of people with schizophrenia, for both research and clinical purposes. The TIBSCSM adds exciting data oriented toward providing a more global service to those with schizophrenia and co-occurring methamphetamine use and their families. It would be significant to discover the reproducibility of the current results and their sensitivity to alteration. However, the study demonstrated that the scale has good psychometric properties. The research results deliver an innovative, valid, and essential scale that may be valuable in routine practice, clinical research, and education.

Limitation
This study reclude the 142 sample that are lower than the rule of a new instrument development due to the limitation of the number of samples.

© 2022 Gunawan J.
This is an open access peer review report distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Joko Gunawan
Belitung Raya Foundation, Belitung, Indonesia instrument with some scientific sections. Moreover, you found an instrument composed of four constructs as follows (1) physical function, (2) self-esteem, (3) role and social enjoyment, and (4) relationship satisfaction. The manuscript is certainly well written and attractive, but I have some major concerns about the instrument development process that prevents me to endorse its acceptance at the present stage. I see the main problems with the statistics that could have led to potentially wrong results and, thus, to completely misleading conclusions.

Title:
Current Title: Development and psychometric testing of the Thai impact and burden of care scale for caregivers of persons with schizophrenia and co-occurring methamphetamine use.
○ Suggestion: to develop and assess the psychometric property test on Burdened Care Caregiver Scale-Thai Version for Schizophrenia and Co-occurring Methamphetamine Use.

English:
English language, grammar, and punctuation needs to be revised.

Aim:
The objective is not only development but includes assessment of psychometric proper also. The objective of the present study was to develop the Thai version of the Impact and Burden of Care Scale for Caregivers of Persons with Schizophrenia and Co-occurring Methamphetamine Use (TIBSCSM) and test its psychometric properties.
Authors need to explain each step therefore, readers can learn from your paper.

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The author missed a critical and necessary step "Generating and item pool". I can't understand how the author gets items. The interview may not get items for new instrument development.

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The author can use Delphi Technique or literature review to get enough items, I am not sure the interview can get items for a new instrument.

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The most important step, authors need to conduct a pilot test for readability, comprehensiveness, administrative feasibility, and scoring of the measures, and to identify logistical management issues.

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Missed preliminary item tryout, it leads to lack of quality instrument for the next step.
○ You need to present CVI: Item-level Content Validity Index (I-CVI) AND Content validity index (I-CVI and S-CVI/Ave).

Sample:
There are 32 items, at least the author needs 160 participants, 142 is lower than the rule of instrument development.

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How did the author recruit 30 subjects for qualitative study and 142 for quantitative approach?
○ The sampling technique is important, must be explained.

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A psychometric test involves multi-stage sampling process but not present it.
○ ○ Data analysis: It is a must need.

Results:
Missed presenting the CVI, it is really needed for a new instrument development.

Discussion:
Ideally, the author(s) discussed statistical analysis. Nevertheless, authors missed the discussion of each construct as the main study, authors need to explain each construct, such as physical function, self-esteem, role, social enjoyment, and relationship satisfaction. The discussion can provide readers an understanding about the researcher's perspective because the researcher is the one who knows the meaning of each construct deeply. significant reservations, as outlined above.
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