Measuring health-related quality of life in adolescents and young adults:: Swedish normative data for the SF-36 and the HADS, and the influence of age, gender, and method of administration

Background: There is a paucity of research about health-related quality of life (HRQL) among adolescents, as studies have to a large extent focused on adults. The main aim was to provide information for future studies in this growing field by presenting normative data for the Short Form 36 (SF-36) and the Hospital Anxiety and Depression Scale ( HADS) for Swedish adolescents and young adults. Additionally, the influence of age and gender, as well as method of administration, was investigated. Methods: A sample of 585 persons aged 13 - 23 was randomly chosen from the general population, and stratified regarding age group ( young adolescents: 13 - 15 years; older adolescents: 16 - 19 years, and young adults: 20 - 23 years) and gender ( an equal amount of males and females). Within each stratum, the participants were randomized according to two modes of administration, telephone interview and postal questionnaire, and asked to complete the SF-36 and the HADS. Descriptive statistics are presented by survey mode, gender, and age group. A gender comparison was made by independent t-test; and one-way ANOVA was conducted to evaluate age differences. Results: Effects of age and gender were found: males reported better health-related quality of life than females, and the young adolescents ( 13 - 15 years old) reported better HRQL than the two older age groups. The older participants ( 16 - 23 years old) reported higher scores when interviewed over the telephone than when they answered a postal questionnaire, a difference which was more marked among females. Interestingly, the 13 - 15-year-olds did not react to the mode of administration to the same extent. Conclusion: The importance of taking age, gender, and method of administration into consideration, both when planning studies and when comparing results from different groups, studies, or over time, is stressed.