title: Factor analyses of a social support scale using two methods.
abstract: OBJECTIVE
  Evaluation and comparison of the factor structure of the Medical Outcomes Study Social Support Survey (MOS-SSS) using both confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) with two samples of people living with HIV/AIDS in China.
  
  
  METHODS
  Secondary analyses were conducted with data from two comparable samples of 320 people living with HIV/AIDS from the same hospital using the same inclusion criteria. The first sample of 120 was collected in 2006, and the second sample of 200 was collected in 2012. For each sample, CFA was first performed on the original four-factor structure to check model fit, followed by EFA to explore other factor structures and a subsequent CFA for model fit statistics to be compared to the original four-factor CFA.
  
  
  RESULTS
  In both samples, CFA on the originally hypothesized four-factor structure yielded an acceptable model fit. The EFA yielded a two-factor solution in both samples, with different items included in each factor for the two samples. Comparison of CFA on the a priori four-factor structure and the new two-factor structure in both samples indicated that both factor structures were of acceptable model fit, with the four-factor model performing slightly better than the two-factor model.
  
  
  CONCLUSIONS
  Factor structure of the MOS-SSS is method-dependent, with CFA supporting a four-factor structure, while EFA yielded a two-factor structure in two separate samples. We need to be careful in selecting the analytic method when applying the MOS-SSS to various samples and choose the factor structure that best fits the theoretical model.
authors.affiliation: Department of Social Medicine and Health Management, Public Health School, Central South University, Upper Mayuanlin Road 238, Changsha, 410008, Hunan, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yu
authors.forename: Cheng-Shi
authors.initials: CS
authors.lastname: Shiu
authors.forename: Joyce P
authors.initials: JP
authors.lastname: Yang
authors.forename: Mingjiong
authors.initials: M
authors.lastname: Wang
authors.forename: Jane M
authors.initials: JM
authors.lastname: Simoni
authors.forename: Wei-ti
authors.initials: WT
authors.lastname: Chen
authors.forename: Joy
authors.initials: J
authors.lastname: Cheng
authors.forename: Hongxin
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000534:rehabilitation*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D003625:Data Collection; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D063868:Patient Outcome Assessment; D011788:Quality of Life; D012944:Social Support; D055815:Young Adult