title: The application of a network approach to Health-Related Quality of Life (HRQoL): introducing a new method for assessing HRQoL in healthy adults and cancer patients.
abstract: OBJECTIVE
  Health-Related Quality of Life (HRQoL) research has typically adopted either a formative approach, in which HRQoL is the common effect of its observables, or a reflective approach--defining HRQoL as a latent variable that determines observable characteristics of HRQoL. Both approaches, however, do not take into account the complex organization of these characteristics. The objective of this study was to introduce a new approach for analyzing HRQoL data, namely a network model (NM). An NM, as opposed to traditional research strategies, accounts for interactions among observables and offers a complementary analytic approach.
  
  
  METHODS
  We applied the NM to samples of Dutch cancer patients (N = 485) and Dutch healthy adults (N = 1742) who completed the 36-item Short Form Health Survey (SF-36). Networks were constructed for both samples separately and for a combined sample with diagnostic status added as an extra variable. We assessed the network structures and compared the structures of the two separate samples on the item and domain levels. The relative importance of individual items in the network structures was determined using centrality analyses.
  
  
  RESULTS
  We found that the global structure of the SF-36 is dominant in all networks, supporting the validity of questionnaire's subscales. Furthermore, results suggest that the network structure of both samples was highly similar. Centrality analyses revealed that maintaining a daily routine despite one's physical health predicts HRQoL levels best.
  
  
  CONCLUSIONS
  We concluded that the NM provides a fruitful alternative to classical approaches used in the psychometric analysis of HRQoL data.
authors.affiliation: Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 WZ, Amsterdam, The Netherlands. j.j.kossakowski@uva.nl.
authors.forename: Jolanda J
authors.identifier: http://orcid.org/0000-0002-6946-1732
authors.initials: JJ
authors.lastname: Kossakowski
authors.affiliation: Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 WZ, Amsterdam, The Netherlands.
authors.forename: Sacha
authors.initials: S
authors.lastname: Epskamp
authors.affiliation: Division of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: Jacobien M
authors.initials: JM
authors.lastname: Kieffer
authors.affiliation: Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 WZ, Amsterdam, The Netherlands.|Interdisciplinary Center Psychopathology and Emotion Regulation, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
authors.forename: Claudia D
authors.initials: CD
authors.lastname: van Borkulo
authors.affiliation: Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 WZ, Amsterdam, The Netherlands.
authors.forename: Mijke
authors.initials: M
authors.lastname: Rhemtulla
authors.affiliation: Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 WZ, Amsterdam, The Netherlands.
authors.forename: Denny
authors.initials: D
authors.lastname: Borsboom
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms; D011594:Psychometrics; D011788:Quality of Life; D011795:Surveys and Questionnaires
keywords: Cancer; Health-Related Quality of Life; Network analysis; Psychometrics; SF-36; Short Form Health Survey