title: Psychometric properties of the eight-item modified Medical Outcomes Study Social Support Survey based on Spanish outpatients.
abstract: OBJECTIVE
  The aim of this study was to examine the psychometric properties of the modified Medical Outcomes Study Social Support Survey (mMOS-SS) in a primary healthcare setting (PHCS).
  
  
  METHODS
  A cross-sectional descriptive study was carried out with Spanish outpatients (N = 903) from a PHCS. Subjects responded to the first eight items of the classic Medical Outcomes Study-Social Support Survey (MOS-SS), in effect the mMOS-SS, and immediately proceeded to give answers to the rest of the scale. Also, sociodemographic, self-reported health status and mood/anxiety disorders data were collected. Factor structure was analyzed using exploratory and confirmatory analysis, internal reliability was determined by Cronbach's standardized alpha, and consistency was evaluated by item-to-total score correlations. Evidences of validity were assessed by Spearman's rank correlations, and using the Mann-Whitney test or Kruskal-Wallis test as appropriate, of differences between the mMOS-SS and the MOS-SS.
  
  
  RESULTS
  Mean scores for the MOS-SS (mean = 4.26, SD = 0.78) and mMOS-SS (mean = 4.34, SD = 0.74) are similar. Cronbach's alpha was 0.96 and 0.91, for the MOS-SS and mMOS-SS, respectively. Item-to-total score correlations of the MOS-SS and mMOS-SS are ≥0.64 and ≥0.70, respectively. Exploratory factor analysis (EFA) [56.63% variance, KMO=0.904; χ2=4396.27], and confirmatory factor analysis (CFA) [CFI=0.95; NNFI(TLI)=0.97; SRMR=0.05; χ2=296.81; RMSEA=0.17] showed a one-factor structure.
  
  
  CONCLUSIONS
  Psychometric properties of the Spanish version of the mMOS-SS in outpatients attending a PHCS are adequate. Factor analysis confirmed a one-factor model with acceptable fit indices.
authors.affiliation: Biomedical Research Foundation, Carlos III Hospital, Madrid Healthcare System, C/Sinesio Delgado, 10, 28029, Madrid, Spain, pgomezc@salud.madrid.org.
authors.forename: Paloma
authors.initials: P
authors.lastname: Gómez-Campelo
authors.forename: Elisa M
authors.initials: EM
authors.lastname: Pérez-Moreno
authors.forename: Carmen
authors.initials: C
authors.lastname: de Burgos-Lunar
authors.forename: Carmen
authors.initials: C
authors.lastname: Bragado-Álvarez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Jiménez-García
authors.forename: Miguel Á
authors.initials: MÁ
authors.lastname: Salinero-Fort
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients / Q000523:psychology*; D011594:Psychometrics; D015203:Reproducibility of Results; D012944:Social Support; D013030:Spain; D011795:Surveys and Questionnaires; D055815:Young Adult