Psychometric Validation of the Growth Hormone Deficiency-Child Treatment Burden Measure (GHD-CTB) and the Growth Hormone Deficiency-Parent Treatment Burden Measure (GHD-PTB).

PURPOSE: The aim was to evaluate the measurement properties of the Growth Hormone Deficiency-Child Treatment Burden Measure-Child (GHD-CTB-Child), a patient-reported outcome (PRO) for children aged 9 to < 13 years; the Growth Hormone Deficiency-Child Treatment Burden Measure-Observer (GHD-CTB-Observer), an observer-reported outcome (ObsRO) version completed by parents/guardians of children with growth hormone deficiency (GHD) aged 4 to < 9 years; and the Growth Hormone Deficiency-Parent Treatment Burden Measure (GHD-PTB), a PRO that assesses the treatment burden of parents/guardians living with children with GHD aged 4 to < 13 years. METHODS: A non-interventional, multi-center, clinic-based study across 30 private practice and large institutional sites in the United States and the United Kingdom was conducted. The sample consisted of 145 pre-pubertal children aged 9 to < 13 years at enrollment with a physician confirmed GHD diagnosis as well as 98 parents/guardians of pre-pubertal younger children aged 4 to < 9 years at enrollment with a physician confirmed GHD diagnosis. The child sample consisted of 59 treatment-naïve children (no prior exposure to growth hormone [GH] therapy; were starting GH treatment at study start per standard of care) and 184 children already maintained on treatment for at least 6 months. At baseline, all study participants completed a paper validation battery including all measures needed to conduct the validation analyses. Follow-up assessments with children in the maintenance group and their caregiver/parent were conducted approximately 2 weeks post-baseline to evaluate test-retest reproducibility. To evaluate sensitivity to change and meaningful change thresholds, treatment-naïve participants in both child and parent/guardian populations were assessed within 1 week of report of minimal improvement between week 3 and week 11 and at week 12. Psychometric analyses were implemented following an a priori statistical analysis plan. RESULTS: Factor analyses confirmed the a priori conceptual domains and Overall score for each measure (GHD-CTB-Child and GHD-CTB-Observer domains: Physical, Emotional Well-being, and Interference; GHD-PTB domains: Emotional Well-being and Interference). Internal consistency was acceptable for all measures (Cronbach's alpha > 0.70). Test-retest reliability was acceptable for the Physical, Emotional, and Overall domains of the GHD-CTB versions, and the Emotional and Overall domains of the GHD-PTB (intraclass correlation coefficient above 0.70). All but one of the convergent validity hypotheses for the GHD-CTB versions and all hypotheses for the GHD-PTB were proven (r > 0.40). Known-groups validity hypotheses were significant for length of time to administer the injections in the GHD-CTB versions (p < 0.001 for Physical, Emotional, and Overall, and p < 0.01 for Interference) and whether parents/guardians versus child gave the injections more often for the Emotional domain of the GHD-PTB (p < 0.05). Associated effect sizes ranged from -0.27 to -0.57 for GHD-CTB versions and from -0.74 to -0.69 for the GHD-PTB, indicating that the measures are sensitive to change. Anchor-based patient and parent/guardian ratings of severity suggest preliminary meaningful change thresholds (GHD-CTB: 6 points for Physical score, 9 for Emotional, and 6 for Interference; GHD-PTB: 10 points for Emotional and 6 for Interference scores). CONCLUSIONS: The psychometric properties of the GHD-CTB-Child, GHD-CTB-Observer, and GHD-PTB support the validity of their use as PRO and ObsRO measures to capture the experiences associated with treatment burden for children with GHD and their parents/guardians in both clinical and research settings. The Clinicaltrials.gov registration number NCT02580032 was first posted October 20, 2015.

Assessing the Impact of Growth Hormone Deficiency (GHD) in Adults: Interpreting Change of the Treatment-Related Impact Measure-Adult Growth Hormone Deficiency (TRIM-AGHD).

BACKGROUND: This study's purpose was to assess the minimal important difference (MID) for the Treatment-Related Impact Measure-Adult Growth Hormone Deficiency (TRIM-AGHD), a patient-reported outcome measure assessing growth hormone deficiency (GHD) impacts. The measure was demonstrated to have adequate psychometric measurement properties, and be reliable and valid. For scores to be interpretable, the TRIM-AGHD must be responsive to treatment benefit and the MID in scores quantified. METHODS: A prospective, non-interventional, observational, clinic-based survey study of naïve-to-treatment adult GHD patients (N = 98) was conducted. Key assessments were at baseline and follow-up (between 4 and approximately 8 weeks), with weekly telephone monitoring post-baseline (last n = 34 patients). Responsiveness was evaluated using the effect size of change scores from baseline to follow-up. MID estimates were derived from distribution-based (half standard deviation [0.5 SD], standard error of measurement [SEm]) and anchor-based methods (patient global rating of change [PGRC]) using change scores from baseline to initial report of minimal improvement in GHD severity. Findings from each method were converged to establish an acceptable MID. RESULTS: Patients were mean age 49.7 years, 65.6% female, and 76.0% Caucasian. The TRIM-AGHD was highly responsive to treatment with the total score effect size being 1.38. For the total score, the 0.5 SD was 8.09 and the SEm was 2.66. The difference found using the PGRC was 20.43. The converged MID value for the total score was 10 points. CONCLUSIONS: The TRIM-AGHD is a highly responsive measure assessing AGHD treatment impacts. A 10-point change score is considered a clinically meaningful improvement.

Understanding Treatment Burden for Children Treated for Growth Hormone Deficiency.

OBJECTIVE: Growth hormone deficiency (GHD) treatment for children requires growth hormone injections, typically administered daily until the child reaches adult height. Child GHD treatment burden is not well understood and no disease-specific measures exist to assess this burden. The purpose of the study was to explore GHD treatment burden for children and their parents by conducting concept elicitation interviews supporting a theoretical model of the impact of GHD treatment. METHODS: Four focus groups (in Germany) and 52 telephone interviews (in the UK and USA) were conducted with children/adolescents with GHD aged 8 to <13 years and parents of children with GHD aged ≥4 to <13 years. The purpose of the interviews was to understand the experience of GHD treatment from the child's perspective, and for parents, the impact of their child's treatment on themselves. Interview transcripts were analyzed thematically based on modified grounded theory principles. RESULTS: Interviews with 70 respondents who produced descriptions (n = 73) of patients experiences with GHD treatment (three parents spoke for two children each) were conducted. Analysis identified three major areas of GHD treatment burden for children: physical; emotional well-being; and interference. Parent burdens identified were: emotional well-being and interference. Modifiers such as treatment efficacy and duration, which may impact the degree of treatment burden severity, were identified. CONCLUSIONS: Overall treatment burden of child GHD is considerable for children and their parents. The concept elicitation and theoretical model can be used to develop a disease-specific outcome measure, which adequately reflects the burden of GHD treatment for children and their parents.

Understanding burden of illness for child growth hormone deficiency.

PURPOSE: Research demonstrates that children and adolescents with growth hormone deficiency (GHD) are impacted in multiple ways beyond their short stature; however, there are no disease-specific measures to assess these impacts. The purpose of this study was to examine the burden of GHD on children and adolescents, and to conduct concept elicitation to develop a model of the impact of GHD to support a disease-specific outcome measure. METHODS: Four focus groups and 52 telephone interviews were conducted with children with GHD and parents/guardians of children with GHD to understand the experience and impacts from the child's perspective, reported by children or parent-observers about the impact on the child. The interviews and focus groups were conducted in Germany, the United Kingdom, and the United States. Interview transcripts were analyzed thematically based on modified grounded theory principles. RESULTS: There were 73 descriptions of patient's experiences elicited from 70 respondents, as three respondents spoke for two children each. A majority of GHD descriptive narratives refer to boy children (n = 51, 69.9%) and a majority of children had taken GHD treatment (n = 64, 89%). Analysis identified four major areas of GHD impact: Signs and Symptoms (beyond short stature), Physical Aspects of Daily Life, Social Well-Being, and Emotional Well-Being. CONCLUSIONS: The burden of GHD in children and adolescents is considerable and not limited to short stature. The severity of GHD impact on children and adolescents appears to be variable and individualized, but these data indicate that early identification and growth hormone treatment may lead to fewer impacts.