Preventing Chronic Disease | Trends in Health-Related Quality of Life Among Adolescents in the United States, 2001–2010 - CDC
Trends in Health-Related Quality of Life Among Adolescents in the United States, 2001–2010
Wanjun Cui, PhD; Matthew M. Zack, MD, MPH
Suggested citation for this article: Cui W, Zack MM. Trends in Health-Related Quality of Life Among Adolescents in the United States, 2001–2010. Prev Chronic Dis 2013;10:120334. DOI: http://dx.doi.org/10.5888/pcd10.120334.
The HRQOL measures include self-rated health and number of physically unhealthy days, mentally unhealthy days, and activity limitation days (2). The self-rated health measure asks the question “Would you say that in general your health is excellent, very good, good, fair, or poor?” We grouped responses into fair or poor health, good health, and very good or excellent health. The measures for unhealthy days asked respondents how many days during the past 30 days their physical or mental health was not good or their physical or mental health limited them from doing usual activities. We grouped responses for these separate measures into 0 days, 1 to 13 days, and 14 to 30 days.
The main independent variable was the interview year of the 5 NHANES survey cycles (2001–2002, 2003–2004, 2005–2006, 2007–2008, and 2009–2010). To assess whether adolescents’ HRQOL varied by family income, we created an interaction term between interview year and family poverty–income ratio. We defined low income as 130% or less of federal poverty guidelines, middle income as more than 130% to 350%, and high income as greater than 350%. We adjusted for possible confounding from sex, race/ethnicity, age, physical inactivity, and cigarette smoking.
We used multinomial logistic regression in SAS-callable SUDAAN 10.0 (6), accounting for NHANES’ complex sample survey design, to estimate both unadjusted percentages (not reported) and percentages adjusted for potential confounders and their 95% confidence intervals (CIs) for the HRQOL outcomes by interview year alone and the interaction between interview year and family poverty–income ratio. We used t tests to detect significant differences between percentages and logistic regression to test for trends.
Table 1). The adjusted percentage of adolescents reporting fair or poor health was significantly higher in 2007–2008 (10.0%) than in 2003–2004 (5.7%). This same pattern occurred among adolescents with low family income (Table 2). The percentage of adolescents from high-income families who reported excellent or very good health also decreased, but the percentage who reported fair or poor health did not increase.
The adjusted percentage of adolescents reporting zero, 1 to 13, or 14 or more physically unhealthy days did not change over the study period (Table 1) or by family income level (Table 2).
Adolescents’ mental health worsened over time, especially recently. The adjusted percentage reporting zero mentally unhealthy days was fairly stable from 2001 through 2006 but declined significantly from 60.9% in 2005–2006 to 49.4% in 2009–2010 (Table 1). Yet, only in adolescents from low-income families did the percentage of zero mentally unhealthy days significantly decrease (from 63% in 2003–2004 to 46% in 2009–2010). The percentage reporting 14 to 30 mentally unhealthy days increased significantly, almost doubling, from 2001–2004 through 2009–2010. However, the adjusted percentage of adolescents who reported 14 to 30 mentally unhealthy days increased significantly only among adolescents from low-income families (from 5% in 2007–2008 to 11% in 2009–2010) and middle-income families (from 4% in 2001–2002 to 10% in 2009–2010); it did not increase significantly among adolescents from high-income families (Table 2). The adjusted percentage of zero activity limitation days was significantly higher in 2003–2004 than in 2009–2010, but the percentage of 1 or more activity limitation days did not increase (Table 1). Among adolescents from low-income families the percentage of zero activity limitation days also significantly decreased between 2005–2006 and 2009–2010 (Table 2).
Our study has several limitations. First, because our analyses covered only 5 biennial cycles, we could not detect whether adolescent HRQOL improved as the economic situation improved more recently. Second, NHANES data are self-reported and subject to misclassification, although the CDC’s HRQOL measures appear valid and reliable among adolescents (10). Third, because NHANES is cross-sectional and not longitudinal, compositional changes to the sample across survey cycles might have reduced our ability to detect trends in this study.
Because adolescence can be challenging and stressful, and because risky behaviors may accompany poor adolescent HRQOL (11), this study’s findings suggest a need to develop policies that help adolescents, especially those from low-income families, to maintain if not improve their HRQOL.
Author Affiliation: Matthew M. Zack, Centers for Disease Control and Prevention, Atlanta, Georgia.
Tendencias en la calidad de vida relacionada con la salud entre adolescentes en los Estados Unidos, 2001–2010
Wanjun Cui, PhD; Matthew M. Zack, MD, MPH
Citación sugerida para este artículo: Cui W, Zack MM. Trends in Health-Related Quality of Life Among Adolescents in the United States, 2001–2010. Prev Chronic Dis 2013;10:120334. DOI: http://dx.doi.org/10.5888/pcd10.120334.
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