title: Measurement and interpretation of social distress using the social difficulties inventory (SDI).
abstract: Cancer has a significant social impact. There is a requirement to undertake formal assessment of this in research and clinical practice.
  
  
  OBJECTIVE
  To establish values of clinically meaningful differences and changes in social distress (SOCD) using the social difficulties inventory (SDI).
  
  
  METHODS
  Newly diagnosed patients treated with curative intent completed the SDI and the EORTC quality of life questionnaire (EORTC QLQ-C30) at baseline, 6, 12 and 24 months. Minimally important differences (MIDs) were estimated using anchor and distribution methods.
  
  
  RESULTS
  One hundred and eighty-eight patients participated. SOCD was elevated at baseline demonstrating the social burden of cancer on patients following diagnosis. Anchor estimates for MIDs were by age groups 3.37 and in comparison to EORTC QLQ-C30 social functioning scale from 0 to 6.27. Using distribution methods: SEM 2.01-4.92 and SD 1.67-3.57.
  
  
  CONCLUSIONS
  For general guidance, an estimate of 3 (range 0-44) is recommended as a clinically important difference, illustrated by case studies and group comparisons.
authors.affiliation: Psychosocial and Clinical Practice Research Group, Cancer Research UK Clinical Centre, Section of Oncology and Clinical Research, University of Leeds, St James's University Hospital, Beckett Street, Leeds LS9 7TF, United Kingdom. e.p.wright@leeds.ac.uk
authors.forename: Penny
authors.initials: P
authors.lastname: Wright
authors.forename: Laura
authors.initials: L
authors.lastname: Marshall
authors.forename: Adam B
authors.initials: AB
authors.lastname: Smith
authors.forename: Galina
authors.initials: G
authors.lastname: Velikova
authors.forename: Peter
authors.initials: P
authors.lastname: Selby
mesh_terms: D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000523:psychology*; D011788:Quality of Life; D013315:Stress, Psychological; D011795:Surveys and Questionnaires