RSFST CFA_METHODS revised

METHODS
PARTICIPANTS
Individuals with schizophrenia were recruited at three community psychiatric rehabilitation centers and one psychiatric day care center at Taipei City Hospital in northern Taiwan from November 2014 to July 2015. Inclusion criteria were as follows: (1) diagnosis of schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5); (2) ages more than 18 years old; and (3) at least an elementary level of education graduating from primary school; and (4) ability to understand and provide informed consent. Exclusion criteria were as follows: (1) severe brain injuries and impaired cognitive ability and (2) with diagnoses of substance use (?). This study was approved by the Institutional Review Board of Taipei City Hospital(TCHIRB-10406117). Informed consent for participation was obtained from the participants personally.
PROCEDURE
Participants who met the inclusion criteria and signed the informed consent were assessed by the raters. The self-report R-SFST was administered in a quiet environment to groups of 6-8 participants at a time. Demographic and clinical information of the participants were collected from clinical records.


INSTRUMENT
The Revised Social Function Scale-Taiwan short version (RSFST) is developed to assess comprehensive domains of social function commonly used to measure social function in patients with schizophrenia (Song, 2001). RSFST consists of 3673 items divided into six domains: 10-item social/withdraw, 10-item sociality, 10-item communications, 13-item leisure activities, 15-item the ability of independence, and 15-item the performance of independence, and employment subscales. The RSFS assesses the frequency of interpersonal interaction with others in recently 3 months on a 4-point scale (0-3) from rare, seldom, sometimes, and often. The score range of the RSFS is 0-219. A higher score represents better social function.  It takes 20 to 30 minutes to fill out the RSFS. 


However, the disadvantages of SFST were as follows: (1) high missing rates on items in SFST, (2) two subscales (independence-competence and independence-performance subscales) having ceiling effects could not discriminate patients with high social function, (3) two subscales had low internal consistency (Chiu et al., 2012). The above results would threaten the validity and reliability of SFST and limit its utility in both clinical and research settings.
As a result, our study revised SFST into the Revised Social Functioning Scale –Taiwan short version (R-SFST). It consists of 27 items divided into six domains: 4-item social/withdraw, 5-item sociality, 5-item communications, 4-item leisure activities, 4-item ability of independence, and 5-item performance of independence.


*RSFS的發展說明，可以放在introduction。主要是參考SFS及SFST兩個版本(要一起引用)。
*由RSFS(73 item)到RSFS short form(27 item)，其domain的名稱，要一致。

DATA ANALYSIS
The statistical procedures were computed using SPSS and EQS. The factorial structure of the general linear model (GLM) was assessed through confirmatory factor analysis (CFA). CFA was conducted to evaluate the 10 6 one-factor structure. The diagonally weighted least squares method was used to estimate CFA parameters (Forero, Maydeu-Olivares, & Gallardo-Pujol, 2009; Minrdila, 2010). We examined goodness-of-fit indices to determine the unidimensional construct of items. Four Five goodness-of-fit indices were used to examine the level of fit between the overall model and data, such as the ratio of chi-square value to the degrees of freedom, comparative fit index (CFI), Tucker-Lewis index (TLI), and the root mean square error of approximation (RMSEA). The criteria of a good model fit were χ2 / df<3.0, CFI<>0.95, TLI>0.95, and RMSEA<0.08 (Bolle, 1989; Hu and Bentler, 1999; Bentler and Bonnett, 1980; Browne & Cudeck, 1993). Models with χ2/df < 3.00, CFI > .90, TLI > .90, and RMSEA < .08 are considered to have acceptable model fit (Dwinger, Kriston, Ha¨ rter, & Dirmaier, 2015).
*再補上這一段說明，我們的model是可接受的。另【<】是小於等於(一下找不到符號)。
Dwinger, S., Kriston, L., Ha¨ rter, M., & Dirmaier, J. (2015). Translation and validation of a multidimensional instrument to assess health literacy.Health Expectations, 18(6), 2776Y2786. doi:10.1111/hex.12252

After a domain presented a sufficient model fit, we estimated the factor loadings of the items to represent the correlation between the item and its corresponding factor. If the factor loading was <0.50, we deleted the item.
* We deleted the items with factor loading less than 0.5. 這需要文獻的支持。

*2nd order CFA,還沒寫。