Longitudinal Trajectories of Illness Perceptions Among Adolescents With Type 1 Diabetes

Adolescence is a critical time in diabetes management, as adolescents take on more responsibilities for their diabetes (Helgeson, Reynolds, Siminerio, Escobar, & Becker, 2008; Wiebe et al., 2014), establish autonomy (Wysocki et al., 1996), and cope with biological changes (Inagaki & Hatano, 2006). As adolescents seek to make sense of their illness, they develop illness perceptions that guide illness management (Leventhal et al., 1997) and are associated with psychological and illness-related outcomes (Hagger & Orbell, 2003). Illness perceptions are defined as a set of beliefs about an illness (Leventhal et al., 1997) that develop through physical experiences, exposure to medical encounters, and interpretation of information from social and factual sources, and are believed to be proximal guides to illness management, even if they are medically incorrect (Hagger & Orbell, 2003; Leventhal et al., 1997). Dimensions of illness perceptions include chronicity (belief that the illness will last for a long time), cyclicality (beliefs about the variability of the illness), consequences (beliefs about the severity of the illness), personal control (one’s own perceived control over the illness), treatment control (beliefs in the efficacy of the treatment regimen), coherence (belief that the illness and its treatment make sense), and emotional representations (beliefs that the illness has negative emotional consequences). Very little work examines how illness perceptions develop during periods of rapid developmental change such as adolescence (Skinner, John, & Hampson, 2000). Cross-sectional research suggests that illness perceptions may differ with age such that older adolescents have a more advanced understanding of their chronic illness than do younger adolescents (Olsen, Berg, & Wiebe, 2008). The goal of this study was to examine trajectories in illness perceptions of type 1 diabetes through the course of adolescence and the association of these perceptions with developmental and diabetes-related outcomes. Across adolescence, illness perceptions may change as adolescents develop in their cognitive and socioemotional understanding (Smetana, Campione-Barr, & Metzger, 2006; Steinberg, 2010) and take on greater responsibility for diabetes care (Wiebe et al., 2014). In early adolescence, changes in levels of intellectual functioning may allow for a greater understanding of symptoms, causes, and consequences of childhood illnesses (Myant & Williams, 2005; Siegelman, Maddock, Epstein, & Carpenter, 1993). For example, older adolescents understand the implications of high glycosylated hemoglobin (HbA1c) values better than younger adolescents (Patino-Fernandez, Eidson, Sanchez, & Delameter, 2010). Additionally, increased experience with illnesses such as type 1 diabetes in children and adolescents is associated with more sophisticated understanding of the illness (e.g., symptom control through diet and insulin administration; Rubovits & Siegel, 1994). During adolescence, this greater experience with the illness coincides with adolescents increasingly managing diabetes independently from their parents (Wiebe et al., 2014), which may affect perceptions of their own and their treatment’s control over the illness. These broader developmental changes may relate to changes in illness perceptions. Cross-sectional findings reveal that older adolescents with type 1 diabetes view the illness as more chronic and severe (Olsen et al., 2008) and treatment having greater control over the illness than younger adolescents (Gaston et al., 2012). In the one study examining illness perceptions over time during adolescence (Skinner et al., 2000), adolescents perceived diabetes as more serious and their treatment as more effective across a 6-month time frame. Understanding developmental trajectories in illness perceptions among adolescents with type 1 diabetes is important because these perceptions guide illness management decisions, and may relate to adherence and psychosocial adjustment. An extensive literature in adults with diabetes and other chronic conditions has linked illness perceptions to adherence and psychosocial adjustment (Hagger & Orbell, 2003). In a recent review involving studies with adolescents, Law, Tolgyesi, and Howard (2012) identified control beliefs as especially important for adolescents’ self-management of diabetes as well as other chronic illnesses. However, results for other perceptions were mixed. For instance, while chronicity beliefs were not associated with adherence in three studies of adolescents with diabetes (Griva, Myers, & Newman, 2000; Law, Kelly, Huey, & Summerbell, 2002; Skinner et al., 2003), Gaston et al. (2012) found chronicity was associated with lower blood glucose monitoring. Similarly, Gaston et al. found that greater perceived consequences were associated with better blood glucose monitoring, whereas Skinner et al. (2000) found perceived consequences predicted poorer dietary self-care in adolescents with type 1 diabetes. Olsen et al. (2008) found that lower coherence was associated with poorer adjustment in adolescents with type 1 diabetes, whereas Law et al. (2002) reported coherence was unrelated to adherence and well-being in adolescents with diabetes, as well as other chronic illness. Owing to inconsistencies in the literature, the nature of the relationships between illness perceptions and diabetes outcomes among adolescents remains unclear. The present study adds to this literature by examining how illness perceptions, developmental factors, and diabetes-related outcomes are longitudinally associated across three time points in a large sample of adolescents with type 1 diabetes. Given the changes in diabetes management that occur across adolescence, as well as normal developmental changes, we anticipated progressions in how adolescents perceive their illness. The goals of this study were to examine: (1) How adolescents’ perceptions of diabetes develop across time; we anticipated increases in personal control, treatment control, consequences, coherence, and chronicity, and decreases in parental control. (2) Whether changes in illness perceptions are associated with cognitive ability and the adolescent’s responsibility for diabetes management; based on previous research, we anticipated that higher baseline cognitive ability and more responsibility for diabetes management would relate to higher personal and treatment control, higher coherence, and lower parental control. (3) Whether illness perceptions across development are associated with diabetes-related outcomes, including HbA1c, adherence, and quality of life (QOL); we expected that personal and treatment control would be associated with more positive diabetes outcomes.