title: Psychometric properties of the disease-specific health-related quality of life instrument VascuQoL in a Swedish setting.
abstract: BACKGROUND
  Traditional outcome measures in peripheral arterial disease (PAD) provide insufficient information regarding patient benefit. It has therefore been suggested to add patient-reported outcome measures. The main aim of this study was to validate the Swedish Vascular Quality of Life questionnaire (VascuQoL) version, a patient-reported PAD-specific health-related quality of life (HRQoL) instrument.
  
  
  METHODS
  Two-hundred PAD patients were consecutively recruited from two university hospitals. Out of the 200 subjects, 129 had intermittent claudication and 71 had critical limb ischemia. Mean age was 70 ± 9 y and 57% of the participants were male. All patients completed SF-36 and VascuQoL at the vascular outpatient clinic, when evaluated for invasive treatment. Risk factors and physiological parameters were registered. Construct validity was tested by correlation analysis versus SF-36 and was also assessed with multitrait/multi-item scaling analysis (MTMI). Sensitivity analysis regarding disease severity identification was performed. Reliability was assessed with Cronbach's alpha and responsiveness by standardized response mean (SRM) calculations.
  
  
  RESULTS
  Significant correlations were demonstrated between relevant subscales of VascuQoL and SF-36. MTMI showed acceptable construct validity, but some scaling-errors. VascuQoL significantly (p < 0.001) discriminated claudicants from critical limb ischemia patients. Cronbach's alpha was 0.94 and SRM 1.02 (sum score).
  
  
  CONCLUSIONS
  The Swedish version of VascuQoL is valid and quantifies central aspects of HRQoL in PAD patients. Sensitivity analysis showed high ability to differentiate between disease severity and SRM illustrated excellent responsiveness. The relative abundance of items however makes use in the everyday clinical setting somewhat difficult.
authors.affiliation: Department of Vascular Surgery, Sahlgrenska University Hospital, Bruna Stråket 11 B, 413 45, Gothenburg, Sweden. joakim.nordanstig@vgregion.se
authors.forename: Joakim
authors.initials: J
authors.lastname: Nordanstig
authors.forename: Jan
authors.initials: J
authors.lastname: Karlsson
authors.forename: Monica
authors.initials: M
authors.lastname: Pettersson
authors.forename: Christine
authors.initials: C
authors.lastname: Wann-Hansson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006305:Health Status Indicators; D006785:Hospitals, University; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis / Q000209:etiology; D007511:Ischemia; D007866:Leg / Q000098:blood supply; D008297:Male; D058729:Peripheral Arterial Disease / Q000150:complications / Q000523:psychology* / Q000628:therapy; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D015203:Reproducibility of Results; D012307:Risk Factors; D011795:Surveys and Questionnaires / Q000592:standards*; D013548:Sweden