Psychometric Evaluation of the German Version of the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) Questionnaire

Abstract

Objective: To evaluate the psychometric properties of a German version of the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire.

Method: IWQOL-Lite scores were obtained from 351 overweight/obese individuals and 127 lean adult volunteers. In addition, a subgroup of 126 obese subjects completed also the German versions of the 36-item short-form health survey (SF-36), the Beck Depression Inventory (BDI), the Eating Disorder Examination-Questionnaire (EDE-Q), and the German validated version of the Three-Factor Eating Questionnaire (TFEQ).

Results: The German version of the IWQOL-Lite has psychometric properties comparable to those found for the original version and demonstrates high internal consistency and excellent construct validity. Furthermore, the German IWQOL-Lite clearly discriminates between groups based on BMI on all subscales and the total score.

Conclusion: The results of the present study suggest that the German IWQOL-Lite is a psychometrically validated instrument with which to measure weight-specific health related quality of life.

Key words

quality of life - obesity - IWQOL-Lite - German - psychometric

References

• 1 Bullinger M, Kirchberger I. Fragebogen zum Gesundheitszustand (SF-36). Göttingen: Hogrefe; 1998
• 2 de A Mariano MH, Kolotkin RL, Petribu K. et al . Psychometric evaluation of a Brazilian version of the Impact of Weight on Quality of Life (IWQOL-Lite) instrument.  Eur Eat Disord Rev. 2010;  18 58-66
• 3 Egle UT, Kahaly GJ, Petrak F. et al . The relevance of physical and psychosocial factors for the quality of life in patients with thyroid-associated orbitopathy (TAO).  Exp Clin Endocrinol Diabetes. 1999;  107 168-171
• 4 Engel SG, Kolotkin RL, Teixeira PJ. et al . Psychometric and cross-national evaluation of a Portuguese version of the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire.  Eur Eat Disord Rev. 2005;  13 133-143
• 5 Fairburn CG, Beglin SJ. The assessment of eating disorders: interview or self-report questionnaire?.  Int J Eat Disord. 1994;  16 363-370
• 6 Gumprecht J, Zelobowska K, Gosek K. et al . Quality of life among diabetic and non-diabetic patients on maintenance haemodialysis.  Exp Clin Endocrinol Diabetes. 2010;  118 205-208
• 7 Hautzinger M, Bailer M, Worall H. et al .Beck-Depressions-Inventar (BDI) Bearbeitung der deutschen Ausgabe. Testhandbuch. Bern: Huber; 1994
• 8 Hays RD. Generic versus disease-targeted instruments. In: Fayers PM, Hays RD (eds). Assessing quality of life in clinical trials: method and practice. New York: Oxford University Press; 2005
• 9 Hilbert A, Tuschen-Caffier B. Eating Disorder Examination-Questionnaire. Deutschsprachige Übersetzung. Münster: Verlag für Psychotherapie, PAG Institut für Psychologie AG; 2006
• 10 Hu L, Bentler PM. Cutoff criteria for fit indexes in covariance structure analysis: conventional criteria versus new alternatives.  Struct Equ Modeling. 1999;  6 1-55
• 11 Kolotkin RL, Crosby RD, Corey-Lisle P. et al . Performance of a weight-related measure of quality of life in a psychiatric sample.  Qual Life Res. 2006;  15 587-596
• 12 Kolotkin RL, Crosby RD, Kosloski KD. et al . Development of a brief measure to assess quality of life in obesity.  Obes Res. 2001;  9 102-111
• 13 Kolotkin RL, Crosby RD, Williams GR. Assessing weight-related quality of life in obese persons with type 2 diabetes.  Diabetes Res Clin Pract. 2003;  61 125-132
• 14 Kolotkin RL, Crosby RD. Manual for the Impact of Weight on Quality of Life Measure (IWQOL and IWQOL-Lite). Durham, NC: Obesity and Quality of Life Consulting; 2008
• 15 Kolotkin RL, Crosby RD. Psychometric evaluation of the Impact of Weight on Quality of Life-Lite Questionnaire (IWQOL-Lite) in a community sample.  Qual Life Res. 2002;  11 157-171
• 16 Mühlhans B, Horbach T, de Zwaan M. Psychiatric disorders in bariatric surgery candidates: a review of the literature and results of a German prebariatric surgery sample.  Gen Hosp Psychiatry. 2009;  31 414-421
• 17 Pudel V, Westenhöfer J. Fragebogen zum Eßverhalten (FEV) – Handanweisung. Göttingen: Hogrefe; 1989
• 18 Stunkard AJ, Messick S. The 3-Factor Eating Questionnaire to measure dietary restraint, disinhibition and hunger.  J Psychosom Res. 1985;  29 71-83
• 19 Ware JE, Kosinski M. Interpreting SF-36 summary health measures: a response.  Qual Life Res. 2001;  10 405-441
• 20 Ware JE, Snow K, Kosinski M. et al .SF-36 Health Survey: manual and interpretation guide. Boston: The Health Institute, New England Medical Center; 1993

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