Understanding the Construct of Fear of Hypoglycemia in Pediatric Type 1 Diabetes

Hypoglycemia is one of the most dangerous consequences of insulin therapy for children and adolescents with T1D, and a primary barrier to optimal glucose control (Cryer, 2012). Episodes of severe hypoglycemia (SH) can be associated with mental disorientation, loss of consciousness, and even seizures, making SH especially frightening to children and their parents (Clarke, Jones, Rewers, Dunger, & Klingensmith, 2009). Youth who maintain tight glycemic control are at increased risk for both moderate and SH episodes, presenting a significant dilemma for families attempting to achieve optimal diabetes management (Lehecka, Renukuntla, & Heptulla, 2012). Given the frequent occurrence of hypoglycemia and its potential life-threatening consequences, it is no surprise that fear of hypoglycemia (FoH) is common for children with T1D and their parents (Barnard, Thomas, Royle, Noyes, & Waugh, 2010; Clarke, Gonder-Frederick, Snyder, & Cox, 1998; Green, Wysocki, & Reineck, 1990; Gonder-Frederick, Clarke, & Cox, 1997; Marrero, Guare, Vandagriff, & Fineberg, 1997; Gonder-Frederick, Nyer, Shepard, Vajda, & Clarke, 2011). In fact, mothers of children with T1D have demonstrated higher levels of FoH than adults with T1D (Clarke et al., 1998; Patton, Dolan, Henry, & Powers, 2008). As parents manage the majority, if not all, of younger children’s diabetes care, FoH, especially during the night, can result in increased parenting stress, perceived parental burden, and more frequent nighttime awakenings to monitor blood glucose (BG) levels (Haugstvedt, Wentzel-Larsen, Rokne, & Graue, 2011; Monaghan, Hilliard, Cogen, & Streisand, 2009; Patton, Dolan, Henry, & Powers, 2007; Streisand, Swift, Wickmark, Chen, & Holmes, 2005). Given the real danger associated with hypoglycemia, some FoH is to be expected, and even adaptive. Adaptive levels of fear are likely associated with appropriate hypoglycemia prevention behaviors, such as more frequent BG monitoring. However, extremely high levels of FoH may lead to the child or parent over-treating initial signs of low BG and contribute to a pattern of management that promotes high BG, with the potential to have a negative impact on glycemic control (Clarke et al., 1998). Higher levels of FoH can also have a negative impact on quality of life and increase perceived diabetes burden in both children with T1D and their parents (Barnard et al., 2010; Johnson, Cooper, Davis, & Jones, 2013). Not surprisingly, parental FoH has been shown to be related to hypoglycemia history, including previous episodes resulting in seizure or loss of consciousness, as well as frequency of episodes (Clarke et al., 1998; Gonder-Frederick, Nyer, et al., 2011; Marrero et al., 1997; Monaghan et al., 2009; Patton et al., 2007, 2008). Personality constructs may also be associated with FoH, with higher levels of FoH found in mothers showing higher levels of trait anxiety, a relationship also found in adults with T1D (Gonder-Frederick, Nyer, et al., 2011; Polonsky, Davis, Jacobson, & Anderson, 1992). In mothers of adolescents, FoH has been shown to be related to maternal beliefs regarding whether their teenager carried fast-acting carbohydrates for hypoglycemia treatment (Gonder-Frederick et al., 2006). In addition, parental FoH can be related to type of insulin regimen, with higher FoH for mothers with children on multiple daily injections (MDI) compared with those with children on insulin pump therapy (Haugstvedt, Wentzel-Larsen, Graue, Sovik, & Rokne, 2010; Muller-Godeffroy, Treichel, Wagner, & German Working Group for Paediatric Pump Therapy, 2009; Nixon & Pickup, 2011). In children and adolescents with T1D, trait anxiety appears also to be associated with FoH (Gonder-Frederick et al., 2006; Gonder-Frederick, Nyer, et al., 2011). However, the relationship between pediatric FoH and previous episodes of hypoglycemia is unclear with research yielding mixed results (Gonder-Frederick et al., 2006; Johnson et al., 2013; Marrero et al., 1997). The most widely used instruments for quantifying FoH in pediatric diabetes are adaptations of the original Hypoglycemia Fear Survey (HFS) developed for adults (Cox, Irvine, Gonder-Frederick, Nowacek, & Butterfield, 1987), including separate versions for children (CHFS) and parents (PHFS) (Barnard et al., 2010; Gonder-Frederick, Nyer, et al., 2011). The CHFS and PHFS are composed of two subscales—a Behavior Subscale that measures different types of behaviors to prevent hypoglycemic episodes and their negative consequences (e.g., Carry fast-acting carbohydrates) and a Worry Subscale that measures different types of concerns related to hypoglycemia and its negative consequences (e.g., No one being around to help during a low). Past research has demonstrated the reliability and validity of both the CHFS and the PHFS (Gonder-Frederick et al., 2006; Gonder-Frederick, Nyer, et al., 2011; Patton et al., 2008) and that children as young as 6 to 8 years of age are able to provide reliable self-reports, with alpha coefficients of 0.71, 0.89, and 0.84 for Behavior, Worry, and Total scores, respectively, compared with alphas of 0.78, 0.87, and 0.87 for 9–11-year-old and 0.59, 0.89, and 0.84 for 12–18-year-old youth (Gonder-Frederick, Nyer, et al., 2011). In spite of their common usage and previous psychometric findings, the factor structures of the CHFS and PHFS have not yet been analyzed. These analyses are vital to gain a better understanding of the constructs underlying pediatric and parental FoH, as well as the impact of fear on diabetes management and outcome. Recent factor analysis of the adult HFS has validated a two-factor solution reflecting the Behavior and Worry subscales (Gonder-Frederick, Schmidt, et al., 2011) but also found that the Behavior subscale is better described by two separate factors reflecting (1) actions aimed at keeping BG levels higher and (2) other strategies to avoid hypoglycemia. A major barrier to previous factor analyses of the CHFS and PHFS has been the lack of pediatric studies with an adequately large sample size. The present study aimed to overcome this barrier by using an aggregated sample of youth with T1D and their parents who participated in studies conducted in our laboratory over the past decade. The purpose of the current study was to conduct the first investigation of the underlying factor structure of the CHFS and PHFS using exploratory factor analysis (EFA). EFA was warranted because it could not be assumed that the pediatric and parent versions would have the same three-factor structure as the adult HFS (Gonder-Frederick et al., 2013; Gonder-Frederick, Schmidt, et al., 2011). Importantly, there are notable discrepancies between the adult and pediatric versions that preclude conducting confirmatory analysis, for example, differences in the number of items, with 33 and 25 items on the adult HFS and pediatric versions, respectively, as well as differences in item content. In addition to CHFS and PHFS responses, these data sets also included a number of demographic, medical, and psychological variables, including trait anxiety questionnaires, hypoglycemia history, BG readings, and HbA1c measures. This allowed us to investigate relationships between factors of the CHFS and PHFS and relevant demographic and clinical variables to assess the construct and concurrent validity of factors, and to explore possible implications of FoH for diabetes management and medical outcome.