Application of a disease-specific, quality-of-life measure (QoL-AGHDA) in growth hormone-deficient adults and a random population sample in Sweden: validation of the measure by rasch analysis

Hormonal changes in veterans with Gulf War Illness

AIMS

Gulf War Illness (GWI) is a multi-system condition of complex etiology and pathophysiology without specific treatment. There is an overlap between the symptoms of GWI and endocrinopathies. This study aimed to identify hormonal alterations in 1990-91 Gulf War (GW) veterans and the relationship between GWI and hormonal dysregulation.

MAIN METHODS

Data from 81 GW veterans (54 with GWI and 27 controls without GWI) was analyzed in a cross-sectional, case-control observational study. Participants completed multiple questionnaires, neuropsychiatric assessments, and a comprehensive set of hormone assays including a glucagon stimulation test (GST) for adult growth hormone deficiency (AGHD) and a high-dose adrenocorticotropic hormone (ACTH) stimulation test for adrenal insufficiency.

KEY FINDINGS

The GWI group had lower quality of life and greater severity of all symptoms compared to controls. Pain intensity and pain-related interference with general activity were also higher in the GWI group. AGHD was observed in 18 of 51 veterans with GWI (35.3 %) and 2 of 26 veterans without GWI (7.7 %) (p = 0.012 for interaction). Veterans with GWI also exhibited reduced insulin-like growth factor 1 (IGF-1) levels and IGF-1 Z-scores compared to controls. One participant with GWI met the criteria for adrenal insufficiency. No significant changes were observed in other hormonal axes.

SIGNIFICANCE

The frequency of AGHD was significantly higher in veterans with GWI compared to controls. Recombinant human growth hormone replacement therapy (GHRT) may become a breakthrough therapeutic option for this subgroup. A large clinical trial is needed to evaluate the efficacy of GHRT in patients with GWI and AGHD.

Quality of Life in Craniopharyngioma: A Systematic Review

BACKGROUND

Craniopharyngiomas are morbid tumors that significantly reduce patients' quality of life (QoL). The lifelong burden of endocrine, visual, hypothalamic, and limbic dysfunction can have disastrous consequences for the physical and psychosocial health of patients. Elucidating the factors that influence QoL could guide therapeutic interventions to improve patient well-being.

METHODS

A systematic review was performed in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement using the PubMed and Medline databases. Studies that had reported patient QoL using validated metrics in both adult and pediatric populations were included. Bias and methodological rigor were assessed using the MINORS (methodological index for nonrandomized studies) criteria.

RESULTS

A total of 25 studies, including 2025 patients, were available for review. Most studies were small, retrospective, cohort studies with a high risk of bias. The QoL of the patients with craniopharyngioma was lower than that of the general population. Hypothalamic involvement was consistently the strongest predictor of QoL. Endocrinopathy contributed to morbidity but could be ameliorated by hormone replacement therapy. Social and emotional dysregulation and a poor memory are common complaints after surgery, and iatrogenic damage to the infundibulum, hypothalamus, limbic system, and frontal lobes might underlie these concerns. Sleep-wake cycle dysfunction and hypothalamic obesity are serious consequences of hypothalamic damage.

CONCLUSIONS

An experienced multidisciplinary team is necessary to optimally manage the complex cases of these patients. The poor QoL of patients with craniopharyngioma is multifactorial. However, the contribution of iatrogenesis is not insubstantial. Improved surgical techniques, focusing on hypothalamic preservation, and adjuvant treatment options are required to improve the well-being of these patients.

Growth hormone deficiency in adults with hypopituitarism-What are the risks and can they be eliminated by therapy?

Growth hormone (GH) deficiency develops early in patients with hypothalamic-pituitary disorders and is therefore common among these patients. GH deficiency in adults is associated with increased morbidity, increased body fat mass, abdominal obesity, dyslipidaemia, reduced exercise capacity, impaired cardiac function as well as reduced self-reported well-being and impaired quality of life. Since recombinant human GH became available as replacement therapy more than 25 years ago, randomised controlled trials and long-term studies, together with meta-analyses, have shown improved outcomes in adult patients with hypopituitarism receiving GH. Many of the features associated with GH deficiency in adults improve, or even normalize, and the safety profile is reassuring. The increased interest in GH deficiency in adults with hypothalamic-pituitary disorders has also contributed to the identification of other factors of importance for an outcome such as the replacement of other pituitary hormone deficiencies, and the management of the underlying hypothalamic-pituitary disease, most commonly a pituitary tumour. In this narrative review, we summarize the burden of GH deficiency in adults with hypopituitarism, the impact of GH replacement on the outcome, as well as safety. Based on currently available data, GH replacement should be considered routine management of adults with hypopituitarism.

Growth hormone (GH) enhances anaerobic capacity: impact on physical function and quality of life in adults with GH deficiency

CONTEXT

Anaerobic capacity is impaired in adults with GH deficiency (GHD), adversely affecting physical function and quality of life (QoL).

OBJECTIVE

To investigate whether GH replacement improves anaerobic capacity, physical function and QoL in adults with GHD.

DESIGN

One-month double-blind placebo-controlled crossover study of GH (0·5 mg/day), followed by a 6-month open phase.

PATIENTS

A total of 18 adults with GHD.

MEASUREMENTS

Anaerobic power (watts) was assessed by the 30-s Wingate test, and aerobic capacity by the VO2 max (l/min) test. Physical functional was assessed by the stair climb test, chair stand test, 7-day pedometry and QoL by the AGHDA questionnaire. Lean body mass (LBM) was quantified by dual-energy X-ray absorptiometry.

RESULTS

GH replacement normalized IGF-1 levels during both study phases. During the 1-month placebo-controlled study, improvement in stair climb and chair stand performance was observed during GH and placebo treatment; however, there were no significant GH effects observed in any outcome measure compared to placebo. Six months of GH treatment significantly increased anaerobic power (P < 0·05), chair stand repetitions (P < 0·0001), daily step count (P < 0·05) and QoL scores (P < 0·001) compared to baseline measurements. GH treatment did not significantly improve VO2 max. Improvement in anaerobic power independently predicted an improvement in energy and vitality domain of QoL (P = 0·03).

CONCLUSIONS

GH replacement improves anaerobic capacity, physical function and QoL in a time-dependent manner in adults with GHD. Improvement in the anaerobic but not aerobic energy system is likely to underlie the improvement in QoL in patients with GHD during GH replacement.

GH deficiency after traumatic brain injury: improvement in quality of life with GH therapy: analysis of the KIMS database

OBJECTIVE

Prevalence of GH deficiency (GHD) caused by traumatic brain injury (TBI) is highly variable. Short-term studies show improvement in quality of life (QoL) during GH replacement (GHR), but long-term data are lacking. The aim of this study was to analyse the clinical characteristics of post-traumatic hypopituitarism and the QoL effects of long-term GHR.

DESIGN/METHODS

Pfizer International Metabolic Database patients with GHD caused by TBI and by non-functioning pituitary adenoma (NFPA) were compared regarding: clinical characteristics at baseline and 1-year of GHR, and QoL response up to 8-years of GHR (QoL-AGHDA total scores and dimensions) in relationship with country-specific norms.

RESULTS

TBI patients compared with NFPA patients were younger, diagnosed with GHD 2.4 years later after primary disease onset (P<0.0001), had a higher incidence of isolated GHD, higher GH peak, a more favourable metabolic profile and worse QoL, were shorter by 0.9 cm (1.8 cm when corrected for age and gender; P=0.004) and received higher GH dose (mean difference: 0.04 mg/day P=0.006). In TBI patients, 1-year improvement in QoL was greater than in NFPA (change in QoL-AGHDA score 5.0 vs 3.5, respectively, P=0.04) and was sustained over 8 years. In TBI patients, socialisation normalised after 1 year of GHR, self-confidence and tenseness after 6 years and no normalisation of tiredness and memory was observed.

CONCLUSION

Compared with NFPA, TBI patients presented biochemically with less severe hypopituitarism and worse QoL scores. GHR achieved clinically relevant, long-term benefit in QoL.

The cost-effectiveness of growth hormone replacement therapy (Genotropin®) in hypopituitary adults in Sweden

BACKGROUND

To evaluate the cost-effectiveness of growth hormone (GH) treatment (Genotropin®) compared with no GH treatment in adults with GH deficiency in a Swedish societal setting.

METHODS

A Markov-type cost-utility simulation model was constructed and used to simulate, for men and women, morbidity and mortality for GH-treated and -untreated individuals over a 20-year period. The calculations were performed using current available prices concerning morbidity-related healthcare costs and costs for Genotropin®. All costs and treatment effects were discounted at 3%. Costs were expressed in Euro (1€ = 9.03 SEK). GH-treated Swedish patients (n = 434) were identified from the KIMS database (Pfizer International Metabolic Database) and untreated patients (n = 2135) from the Swedish Cancer Registry and the Hospital Discharge Registry.

RESULTS

The results are reported as incremental cost per quality-adjusted life year (QALY) gained, including both direct and indirect costs for GH-treated versus untreated patients. The weighted sum of all subgroup incremental cost per QALY was €15,975 and €20,241 for men and women, respectively. Including indirect cost resulted in lower cost per QALY gained: €11,173 and €10,753 for men and women, respectively. Key drivers of the results were improvement in quality of life, increased survival, and intervention cost.

CONCLUSIONS

The incremental cost per QALY gained is moderate when compared with informal thresholds applied in Sweden. The simulations suggest that GH-treatment is cost-effective for both men and women at the €55,371 (SEK 500,000 - the informal Swedish cost-effectiveness threshold) per QALY threshold.

Effects of growth hormone treatment in adults with Prader-Willi syndrome

OBJECTIVE

Since limited data exist on adults with Prader-Willi syndrome (PWS) and growth hormone (GH) treatment, we report our experience on the effects of treatment for one year on body composition, physical activity, strength and energy expenditure, diet, general chemistry and endocrine data with quality of life measures.

DESIGN

We studied 11 adults with PWS (6F:5M; average age=32 yrs) over a 2 year period with GH treatment during the first year only. Electrolytes, IGF-I, glucose, thyroid, insulin, lipids, body composition, physical activity and strength, diet, energy expenditure and quality of life data were collected and analyzed statistically using linear modeling at baseline, at 12 months following GH therapy and at 24 months after treatment cessation for 12 months.

RESULTS

Total lean muscle mass was significantly increased (p<0.05) during GH treatment along with moderate-vigorous physical activity and plasma IGF-I and HDL levels, but returned to near baseline after treatment. Percent body fat decreased during the 12 months of GH treatment but increased after treatment.

CONCLUSIONS

Previously reported beneficial effects of GH treatment in children with PWS were found in our adults regarding body composition, physical activity and plasma HDL and IGF-I levels. Several beneficial effects diminished to near baseline after cessation of GH treatment for 12 months supporting the continuation of treatment in PWS into adulthood and possibly adults not previously treated during childhood.

IGF-I bioactivity might reflect different aspects of quality of life than total IGF-I in GH-deficient patients during GH treatment

CONTEXT

No relationship has been found between improvement in quality of life (QOL) and total IGF-I during GH therapy.

AIM

Our aim was to investigate the relationship between IGF-I bioactivity and QOL in GH-deficient (GHD) patients receiving GH for 12 months.

METHODS

Of 106 GHD patients, 84 on GH treatment discontinued therapy 4 weeks before establishing baseline values and 22 were GH-naive. IGF-I bioactivity was determined by IGF-I kinase receptor activation assay, total IGF-I by immunoassay (Immulite), and QOL by the disease-specific Question on Life Satisfaction Hypopituitarism (QLS-H) module and by the general SF-36 questionnaire (SF-36Q).

RESULTS

IGF-I bioactivity increased after 6 months (-2.5 vs -1.9 SD, P < .001) and did not further increase after 12 months (-1.8 SD, P = .23); total IGF-I increased from -2.3 to -0.9 SD (P < .001) and to -0.6 SD (P = .005), respectively. QLS-H did not change over 12 months (-0.66 ± 0.16 to -0.56 ± 0.17 SD [P = .42] to -0.68 ± 0.17 SD [P = .22]). The mental component summary of the SF-36Q increased from 47.4 (38.7-52.8) to 50.2 (43.1-55.3) (P = .001) and did not further improve (49.4 [42.1-54.1], P = .19); the physical component summary did not change (47.5 [42.0-54.2] vs 47.0 [41.9-55.3], P = .91, vs 48.3 [39.9-55.4], P = .66). After 12 months, IGF-I bioactivity was related to QLS-H (r = 0.28, P = .01); total IGF-I was not (r = 0.10, P = .37). IGF-I bioactivity and total IGF-I were related to PCS (r = 0.35, P = .001; and r = 0.31, P = .003).

CONCLUSION

IGF-I bioactivity remained subnormal after GH treatment and was positively related to QLS-H, whereas total IGF-I was not. This suggests that IGF-I bioactivity reflects different aspects of QOL than total IGF-I in GHD patients during GH treatment.

Mortality and socioeconomic status in adults with childhood onset GH deficiency (GHD) is highly dependent on the primary cause of GHD

OBJECTIVE

Childhood onset GH deficiency (CO-GHD) is associated with increased morbidity and mortality; however, the patients' socioeconomic profile as adults is not fully known.

DESIGN

Register study using Danish nationwide registries. Two hundred and sixty GHD males and 156 GHD females and 25,358 male and 15,110 female controls were included.

METHODS

Information was obtained concerning cohabitation, parenthood, education, income, retirement, convictions, and death. Income was analyzed using conditional logistic regression, and other outcomes were analyzed using Cox regression. Subgroups of GHD patients with malignant tumors, craniopharyngioma, idiopathic GHD, and others were investigated separately.

RESULTS

Both male and female GHD patients had a significantly worse outcome on all studied socioeconomic parameters. Fewer GHD patients lived in partnerships and entered them later (male hazard ratio (HR): 0.31; female HR: 0.33), had fewer parenthoods (male HR: 0.26; female HR: 0.26), lower educational level (male HR: 0.58; female HR: 0.48), lower income, higher risk of retirement (male HR: 13.4; female HR: 24.2), and fewer convictions (male HR: 0.67; female HR: 0.49). Mortality was increased (male HR: 10.7; female HR: 21.4). Adjusted for marital and educational status, male HR of death was 5.2 and female HR 10.5. Patients with idiopathic GHD had a socioeconomic profile similar to controls.

CONCLUSION

The primary causes of CO-GHD and concomitant diseases severely impair socioeconomic conditions and impact mortality; only the subgroup of patients with idiopathic GHD conditions was similar to the background population.

The development of the Tuebingen Cushing's disease quality of life inventory (Tuebingen CD-25). Part II: normative data from 1784 healthy people

OBJECTIVE

In part I of the study, a health-related quality of life (HRQoL) inventory for Cushing's disease (CD), the Tuebingen Cushing-25 quality of life inventory (Tuebingen CD-25) was developed. In this second part, we aimed to assess normative data from healthy controls (HC) with which the individual patients' scores can be compared.

DESIGN

Cross-sectional study.

PARTICIPANTS

Sixty-three patients with CD (52 women, 11 men) and 1784 HC (1210 women, 574 men) filled out the Tuebingen CD-25.

MEASUREMENTS

HC received the inventory as a nondisease-specific quality of life questionnaire omitting the introductory sentence 'Because of my Cushing's disease' which was included in the CD group to be able to compare HRQoL in persons with and without CD. Slight and severe impairments were categorized according to the following principles: percent ranges >84.0% were classified as slight and percent ranges >95.0% as severe impairment.

RESULTS

In 28.6% of our patients with CD, we found slight and in 41.3% severe impairment in the Total Score of the Tuebingen CD-25 compared with HC. Less than one-third of our patient sample presented with unimpaired HRQoL. In the patient population, impairment was found in all scales of the Tuebingen CD-25 to a similar extent (P = 0.444), pointing to the fact that all HRQoL domains are similarly impaired. We observed that female patients perceived a worse HRQoL than men in the domains depressive symptoms and social environment (P < 0.05).

CONCLUSION

The Tuebingen CD-25 is a feasible instrument to assess HRQoL in CD in a clinical and investigative setting and provides normative data for all age groups and genders.

GH deficiency during the transition period: clinical characteristics before and after GH replacement therapy in two different subgroups of patients

OBJECTIVE

To study two subsets of patients with GH deficiency (GHD) during the transition period: childhood onset GHD (CO-GHD) and patients who develop GHD during the transition phase (TO-GHD) before and after GH replacement.

PATIENTS AND MEASUREMENTS

In 1340 GHD subjects from KIMS (Pfizer International Metabolic Database), CO (n=586) or TO (n=754), background characteristics, anthropometric measurements, IGF-1, lipids and quality of life (QoL) were evaluated at baseline and after 3 years of GH replacement.

RESULTS

Both groups responded similarly to GH treatment. Changes of clinical outcomes were mainly determined by their value at baseline. Onset of the disease in childhood or transition period did not appear to be a significant predictor of response in any of the clinical outcomes.

CONCLUSIONS

Age at GHD diagnosis was a significant predictor for many outcomes at baseline, but disease onset did not appear as an independent predictor concerning changes after 3 years of GH treatment. The results suggest that GH replacement during the transition period should be considered independently of the onset of the deficiency.

Prediction of improvement in quality of life (QoL-AGHDA) in adults with growth hormone deficiency by normative reference limits: data of the German KIMS cohort

OBJECTIVE

The objective of the present study was to calculate sex- and age-specific normative values for health-related quality of life (HRQoL) in Germany using quantile regression. Furthermore, we investigate the estimates of these normative data to and to predict the improvement of QoL-AGHDA scores in the German KIMS cohort during growth hormone treatment.

DESIGN

Normative data of HRQoL was assessed by quality of life assessment of growth hormone deficiency (GHD) in adults (QoL-AGHDA) in a representative sample of the German population (n=4172). Corresponding data for 888 patients with GHD were retrieved from the German KIMS cohort (Pfizer International Metabolic Database).

RESULTS

The overall mean QoL-AGHDA score of the general population was 4.8±5.2. ANOVA indicated that variability in QoL-AGHDA scores did not differ significantly across gender (p=0.20), whereas age was a significant predictor (p<0.001). Given the QoL-AGHDA score distribution of the general population, we calculated reference values based on quantile regression. In KIMS patients we observed significantly higher QoL-AGHDA scores, 7.9±6.5 (p<0.001), before GH treatment. The optimal predictive QoL-AGHDA score was 6 (70th percentile) with a sensitivity of 0.57 and a specificity of 0.70 in ROC analysis. Furthermore, a baseline QoL-AGHDA score above the 70th percentile allowed predicting an improvement of QoL by GH treatment.

CONCLUSIONS

This study established normative reference values for the QoL-AGHDA in a representative sample of the German population. Based on these normative data a QoL-AGHDA cut-off value for prediction of improvement was investigated for the German population, which may facilitate clinical assessment of HRQoL response to GH replacement for patients with GHD.

The brazilian version of the Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA): Four-stage translation and validation

OBJECTIVE

This study reports on the Brazilian Portuguese adaptation of the QoL-AGHDA (Quality of Life Assessment of Growth Hormone Deficiency in Adults) for use in adult growth hormone deficient (GHD) patients.

MATERIALS AND METHODS

The translation process adopted the dual panel methodology. The questionnaire was tested through field-test interviews (16 GHD patients). In the final stage, data from 120 GHD patients (81 included in a test-retest analysis) were analyzed for internal consistency, test-retest reliability, convergent validity and validity among known groups.

RESULTS

The translation panels were successful and the draft version was amended to improve the wording as a result of the field-test interviews. Cronbach's alpha was 0.90 and test-retest reliability 0.88. QoL-AGHDA scores had the expected pattern of association with NHP scale scores and QoL-AGHDA was able to differentiate significantly between patients based on patient-reported general health (p < 0.01) and QoL (p < 0.01).

CONCLUSIONS

The adaptation of the QoL-AGHDA for a Brazilian population was successful and the adapted questionnaire was shown to be reliable and valid.

Deriving reference values and utilities for the QoL-AGHDA in adult GHD

BACKGROUND

Quality of life (QoL) measures are important in growth hormone (GH) deficiency (GHD) in adults. Ideally, for use in health economics, QoL should be expressed in utilities. The aim of this study was to obtain reference values and utilities for QoL of GHD in adults in Belgium and the Netherlands.

METHODS

The study was conducted in three stages: (1) The Quality of Life-Assessment for Growth Hormone Deficiency in Adults (QoL-AGHDA) and the EQ-5D were administered in a representative sample of 6,875 individuals from the Belgian and 1,400 individuals from the general Dutch population. The EQ-5D(index) can be used to estimate utilities. Using a regression, utilities were predicted from the QoL-AGHDA. (2) QoL-AGHDA scores were obtained from 299 Belgian and 234 Dutch adult patients with GHD and no GH replacement. These scores were converted to utilities and compared the burden of disease with other patient groups. (3) To test the criterion validity, the 'standard' EQ-5D(index) was used in a subsample of 64 Dutch GHD patients and compared with the predicted utilities.

RESULTS

We obtained data from 1,026 Belgian (response rate = 15%) and 1,038 Dutch respondents (response rate = 74%). The Belgian mean QoL-AGHDA value was 6.95 (90% range = 14.00), and the Dutch mean was 5.48 (range = 13.00). The R (2) of the regression model to predict the EQ-5D(index) was 0.360 (Belgium) and 0.482 (the Netherlands). We demonstrated a considerable burden of disease in GHD patients, comparable to patients with hypertension or with type II diabetes. The criterion validity was 0.407 (intraclass correlation, ICC).

CONCLUSIONS

Interventions in GHD can now be evaluated more validly in Belgium and the Netherlands.

Application of the disease-specific Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA) questionnaire in a general population: results from a French panel study

OBJECTIVES

To assess the psychometric properties of the disease-specific Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA) questionnaire in a general population, and collect French normative data.

METHODS

A postal survey was conducted on 2900 adult panelists representative of the French population. The participants were asked to complete a questionnaire including the QoL-AGHDA and an evaluation of their overall health status (OHS). The QoL-AGHDA score ranges from 0 to 25, a lower score indicating better QoL. Psychometric properties of the QoL-AGHDA were assessed. The mean QoL-AGHDA scores were described by sex and age groups.

RESULTS

The return rate was 75%. The quality of completion and internal consistency reliability were good: 95% of the respondents completed all 25 QoL-AGHDA items and Cronbach's alpha was 0.86. The QoL-AGHDA score was able to discriminate between the respondents according to their OHS (from 1.5 for excellent to 12.3 for poor OHS, P < 0.001). The mean QoL-AGHDA score was 4.6 for the overall population, 5.1 for females and 4.2 for males, and ranged from 4.8 for the youngest to 6.1 for the oldest respondents.

CONCLUSIONS

The QoL-AGHDA questionnaire showed good psychometric properties when administered in the French population. French reference values were collected, completing the QoL-AGHDA normative database already available in several European countries.

Treatment of adult growth hormone deficiency: who, why and how? A review

Adult growth hormone deficiency (AGHD) is nowadays recognized as a distinct clinical entity and replacement therapy has become a standard practice. Reflecting on the accumulated evidence, questions nevertheless arise. Should all AGHD patients be treated? What dose of GH should be given and for how long? What are the real long-term benefits, in particular regarding life expectancy? if the diagnosis of severe GHD is firmly established and if there is no contra-indication (such as an active cancer or uncontrolled diabetes), it is worthwile initiating GH replacement therapy. Treatment can indeed correct the abnormal body composition, improve various adverse cardiovascular parameters and risk factors, increase muscle strength and bone mineral density and, although to a variable degree, improve the patient's quality of life and psychological well-being. Treatment should be started with very low doses to avoid side-effects related to fluid retention and should then be gradually titrated against IGF-I values, clinical response and individual tolerance.There is unfortunately no confirmed predictive factor for the overall therapeutic response in a given individual. Thus, the decision to whether or not pursue the therapy will depend on the ratio of perceived and expected benefits over cost and risks of treatment, as well as on the persistent motivation of the patient.

Assessment of quality of life in adult patients with GH deficiency: KIMS contribution to clinical practice and pharmacoeconomic evaluations

Quality of life (QoL) has emerged as an important construct that has found numerous applications across healthcare-related fields, ranging from research and clinical evaluation of treatment effects to pharmacoeconomic evaluations and global healthcare policy. Impairment of QoL is one of the key clinical characteristics in adult GHD and has been extensively studied in the Pfizer International Metabolic Database (KIMS). We provide summarized evidence on GH treatment effects for both clinical and health economic applications based on the KIMS data. The primary focus is on those aspects of QoL research that cannot be investigated in the traditional clinical trial setting, such as specific patient subgroups, cross-country comparisons and long-term follow-up. First, the impact of age, gender, disease onset, primary aetiology, extent of hypopituitarism, previous radiotherapy and obesity on QoL before and during long-term GH replacement is discussed. Secondly, the studies on QoL in relation to country-specific normative values are reviewed. Finally, health economic data derived from KIMS including both burden of disease and utility assessment are evaluated. We conclude that the wide spectrum of analyses performed on the KIMS data allows for practical application of the results not only to research and clinical practice but also to health policy and global medical decision making.

Reduced cardiac functional reserve and quality of life in adults with GH deficiency

INTRODUCTION

Patients with severe GH deficiency (GHD) suffer with a reduced quality of life in addition to diverse changes in cardiac size and performance. So far, the cardiac reserve ability to maintain the circulation during peak exercise has not been measured. We tested the hypothesis that patients with severe GHD have reduced cardiac reserve function compared with healthy controls and that this could explain, in part, their reduced quality of life.

AIMS

Eighteen patients with severe GHD and an assessment of GHD in adults (AGHDA) score > or =11 (mean 20.0, range 12-25) were studied and compared with 18 age-, sex- and body mass index-matched healthy controls. Peak cardiac power and cardiorespiratory fitness were investigated using noninvasive haemodynamic measurements during maximal cardiopulmonary exercise testing.

RESULTS

Compared with matched controls, the cardiac power of GHD patients during exercise to volitional exhaustion was significantly reduced by 15% (mean +/- SD 4.4 +/- 1.0 W vs. 5.2 +/- 1.0 W, P = 0.02). Patients with GHD also had lower cardiac chronotropic reserve (peak heart rate 154 +/- 21/min vs. 174 +/- 11/min, P = 0.001) and a lower cardiac pressure-generating capacity (systolic blood pressure 160 +/- 25 mmHg vs. 200 +/- 15 mmHg, P < 0.0001). We found no correlation between any measure of peak cardiac power or function and the AGHDA score.

CONCLUSION

Using this robust noninvasive method of assessing functional cardiac pumping capacity, we have for the first time shown that, while patients with severe GHD have a significantly impaired cardiac functional reserve associated with chronotropic incompetence and impaired pressure-generating capacity, this does not correlate with their reduced quality of life assessed using the current standard AGHDA score.

Quality of life in congenital, untreated, lifetime isolated growth hormone deficiency

Impaired quality of life (QoL) is commonly described as being associated with growth hormone (GH) deficiency (GHD), and beneficial effects of GH replacement therapy on QoL have been reported. However, most studies examined heterogeneous cohorts of patients GHD of varying etiologies, severities and age of onset. Most of these patients miss other pituitary hormones, whose replacement can also influence QoL. We studied the QoL of a homogeneous cohort of 20 adults with isolated GH deficiency (IGHD) due to the same mutation in the GH-releasing hormone receptor gene (IGHD, 10 men) using the Life Satisfaction Hypopituitarism Module (QLS-H), and compared them with 20 matched controls residing in the same community (CO, 10 men). Additionally, the IGHD group was evaluated after 6 months of treatment with bi-monthly depot GH, and after 12 months from its interruption. There was no difference in the total score of QoL (TSQoL) or in any of the nine categories that composes the questionnaire between IGHD and CO. Similar results were obtained when data were analyzed by sex. GH treatment only increased satisfaction with physical endurance, but did not cause an increase in the TSQoL. We conclude that in this unique population congenital, untreated, lifetime IGHD does not reduce QoL, and treatment with GH for 6 months only causes improvement in satisfaction with physical resistance.

Health-related quality of life and IGF-1 in GH-deficient adult patients on GH replacement therapy: analysis of the German KIMS data and the Study of Health in Pomerania

OBJECTIVE

To analyse 12-month response to GH treatment in a single-country cohort of hypopituitary adult patients with GH deficiency (GHD) in regards to health-related quality of life (HRQoL) and insulin-like growth factor-1 (IGF-1) compared with values from general population sample. Moreover, association between the response in HRQoL and the IGF-1 values in patients and in the background population was investigated.

DESIGN

HRQoL was assessed by quality of life assessment of GH deficiency in adults (QoL-AGHDA) in 651 patients retrieved from the German KIMS (Pfizer International Metabolic Database) before and after 12 months of GH replacement and in a sample drawn from a cross-sectional study in Germany (n=2734). IGF-1 was measured in KIMS patients and in the population-based study with the same assay technique.

RESULTS

In KIMS patients, mean QoL-AGHDA scores before GH replacement were 9.2+/-6.8 (8.7+/-6.8) in women (men) and in the general population sample 4.5+/-5.3 (4.3+/-5.0) in women (men). Mean differences in QoL-AGHDA scores were statistically significant for all age categories (P<0.05). The mean IGF-1 SDS of KIMS patients before GH replacement was -1.1+/-1.4 (-0.8+/-1.4) in women (men). After GH replacement, a significant increase of IGF-1 concentration and a significant decrease of QoL-AGHDA scores near to age- and gender-specific population-based values were observed.

CONCLUSIONS

This study confirms an improvement in HRQoL and an increase of IGF-1 SDS in GH-replaced adults, which approximated the values of general population. However, there was no association between IGF-1 values and HRQoL assessment as one of the important treatment outcomes.

Quality of life in growth hormone deficiency and acromegaly

Quality of life (QoL) has emerged as an end point in the evaluation of adults with growth hormone deficiency and acromegaly. QoL is measured with questionnaires designed to be used in general population or any kind of disease (generic) or aimed at the specific dimensions affected in a determined condition; these latter ones are more likely to identify the impairments caused by the underlying disease and the benefits of treatment. QoL, which is severely impaired in adults with growth hormone deficiency, improves and normalizes after growth hormone replacement therapy and this effect is maintained over several years. Acromegalic patients also exhibit severe impairment of QoL, which despite improvement after successful therapy still remains below the reference values of normal population. QoL in these chronic endocrine diseases can be used as an measure for clinical and therapeutic evaluation.

Rasch analysis of the scoring scheme of the HADS Depression subscale in Chinese stroke patients

The Hospital Anxiety and Depression Scale (HADS) is a widely used screening instrument for depression in medically ill patients. The purpose of this study was to examine the optimal scoring scheme, unidimensionality and item fit of the depression subscale of the HADS (HADS-D) in stroke survivors. A research assistant administered the HADS-D to 100 Chinese patients with acute stroke who were consecutively admitted to a general hospital. A psychiatrist, who was blind to the HADS-D scores, administered the SCID-DSM-III-R to all 100 patients and made a DSM-IV diagnosis of depression, which served as the benchmark for judging the performance of the HADS-D in screening for depression. Rasch analysis has shown that the HADS-D was unidimensional; low endorsements for the higher coded alternative response categories were found in the sample. In clinical samples with a low frequency of depression, the scoring categories of the HADS-D may be reduced.

Using EQ-5D to derive general population-based utilities for the quality of life assessment of growth hormone deficiency in adults (QoL-AGHDA)

OBJECTIVE

Disease-oriented quality of life (QoL) measures that are not preference-based lack legitimacy for direct use in cost-utility analyses. This has prompted the search for other methods for deriving utilities. The QoL Assessment of Growth Hormone Deficiency in Adults questionnaire (QoL-AGHDA) is a disease-oriented measure used to assess impairment in QoL in adults with growth hormone deficiency. The present study was designed to generate a model for deriving utilities from the QoL-AGHDA.

METHODS

The EQ-5D, the QoL-AGHDA, and demographic questions were mailed to a random sample (n = 3005) of the Swedish population (response rate 65%). Multiple regression analysis was used to obtain cross-validated parameters of QoL-AGHDA-based utilities. Two models were developed (simple and full versions). The simple version used the EQ-5D(index) (derived from European values) as the dependent variable, and age, sex, and QoL-AGHDA score as independent variables in a regression analysis. The full model utilized all available demographic information. The QoL-AGHDA scores were thus transformed into a single score (0-1), corresponding to the QoL-AGHDA-based utility.

RESULTS

The simple transformation algorithm was U (QoL-AGHDA-based utilities) = 1.05 - 0.0189 x QoL-AGHDA score - 0.00238 x age - 0.0127 x sex (male = 0; female = 1). The mean of the weighted estimate for the population (n = 1752) was 0.85 (SD 0.10). The estimate for men (n = 861; mean 0.86; SD 0.10) was higher (P < 0.001) than for women (n = 891; mean 0.84; SD 0.10).

CONCLUSION

For practical reasons, the simple model can be recommended for deriving utilities directly from the QoL-AGHDA for the Swedish population.

Validation of the Japanese version of the Quality of Life-Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA)

OBJECTIVE

To evaluate validity and reliability of the Japanese version of the Quality of Life-Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA).

DESIGN

Observational study; cross-sectional, longitudinal.

METHODS

Seventy-five adults with growth hormone deficiency completed the SF-36 (a generic health-related QOL scale) and the QoL-AGHDA before growth hormone replacement therapy and approximately 3 weeks later (when the therapy began). A sample (n=1000) of controls from the general population was also studied. We computed rates of missing data, measured reproducibility and internal consistency reliability, and tested for known-groups validity, concurrent validity, unidimensionality (by principle component analysis), and content validity.

RESULTS

Rates of missing data were low (0-1.4%). The mean of QoL-AGHDA scores in the patients was 8.2 (SD, 6.4). The scores were reproducible (k=0.41-0.78), and internally consistent (alpha=0.91) and the scale was unidimensional. QoL-AGHDA scores were associated with SF-36 scores as hypothesized. Scores were significantly higher in the patients than in controls (8.1+/-0.7, and 5.6+/-0.2, P<0.001). Discrimination between patients and controls was slightly better using scores on the "General Health" and "Role Physical" subscale of the SF-36 as explanatory variables than using QoL-AGHDA scores.

CONCLUSIONS

The QoL-AGHDA's reliability, validity, and rates of missing data were satisfactory, and the scale was confirmed to be unidimensional. However, because some subscales of the SF-36 were better for discriminating patients from controls, the content validity of the QoL-AGHDA may need to be re-evaluated.

Efficacy and safety of growth hormone (GH) in the treatment of adult Japanese patients with GH deficiency: a randomised, placebo-controlled study

OBJECTIVE

The aim of this study was to assess the effect of growth hormone (GH) replacement therapy on lean body mass (LBM) and other variables including body fat mass, serum lipids and quality of life measures in GH-deficient Japanese adults.

DESIGN

This was a multicentre, double-blind, placebo-controlled, parallel group study. Following initial screening, patients were randomly assigned to GH treatment (n=37) or placebo (n=36). GH treatment was started at an initial dose 0.003 mg/kg/day s.c. each day for the first 4 weeks after which the dose was increased to 0.006 mg/kg/day for 4 weeks and then to 0.012 mg/kg/day for the last 16 weeks (n=37). Body composition, serum lipids, serum IGF-I and IGFBP-3 levels were measured during the 24-week study. Short Form-36 and Quality of Life Assessment of GH Deficiency in Adults scores were also determined.

RESULTS

LBM was significantly increased from baseline at 24 weeks in GH-treated patients, with a mean (+/-SD) increase of 4.7% (+/-5.3%) compared with an increase of 1.0% (+/-4.4%) in the placebo group (p<0.0001 versus baseline, p=0.0003 versus placebo). Percentage body fat decreased significantly from baseline in GH-treated patients (9.3%, p<0.0001), compared with a non-significant 0.2% increase in the placebo group (p<0.0004 for difference between treatment groups). In addition, significantly increased serum IGF-I and IGFBP-3 levels and improvements in the patients' serum lipid profiles were observed in patients who received GH therapy. Changes in quality of life measures did not differ between treatments, probably because of the small number of patients studied. GH therapy was well tolerated, with adverse events of any cause reported in 86.5% of the GH treatment group and 83.3% of the placebo group.

CONCLUSION

GH treatment significantly improved body composition and serum lipid profiles in adult Japanese patients with GH deficiency compared with placebo and had no clinically relevant adverse effects.

Effects of Growth Hormone on Cognitive Function

Whether growth hormone deficiency (GHD) and/or treatment in childhood and adolescence influences cognitive outcome in children with GHD or girls with Turner syndrome (TS) is controversial. Previous studies also suggest that quality of life (QoL) is reduced in adults with GHD, particularly in the areas of social isolation and fatigue. Baseline QoL scores were significantly lower in patients with GHD than in the general population of the same age, gender, and nationality. Unfortunately, few data are available describing QoL in children with GHD. TS is a genetic disorder characterized by short stature, gonadal dysgenesis, and a particular neurocognitive profile of normally developed language abilities (particularly verbal intelligence quotients) and impaired visual-spatial and/or visual-perceptual abilities. This study evaluated the effects of GH treatment on neurocognitive function in girls with TS who were enrolled in a long-term, double-blind, placebo-controlled trial of the effects of GH treatment on final adult height. Treatment duration ranged from 1 to 7 years. The major result of this study was the absence of GH treatment effects on cognitive function in girls with TS. GHD and/or treatment in childhood and adulthood influences cognitive and/or QoL outcomes in some but not all studies. This study did not support a role for GH in influencing the characteristic nonverbal neurocognitive deficits associated with TS. However, evaluation of QoL should be a part of the routine clinical management of patients with GHD or TS.

Quality of life assessment of growth hormone deficiency in adults (QoL-AGHDA): comparison of normative reference data for the general population of England and Wales with results for adult hypopituitary patients with growth hormone deficiency

BACKGROUND/AIM

Age- and gender-specific reference values for the quality of life (QoL) measures used in assessing the impact of growth hormone deficiency (GHD) are important. The objective of this study was to develop such data for the QoL-AGHDA instrument for the population of England and Wales and to demonstrate the QoL deficit in patients with GHD.

METHODS

For the purpose of this study, a questionnaire was developed that contained the EurQoL EQ-5D, QoL-AGHDA, questions recording an individual's general situation and social functioning, and a self-reported five-point rating scale of general health. The questionnaire was mailed out to a sample of 1,190 individuals drawn from the general population of England and Wales. Corresponding data for 836 patients were retrieved from KIMS (Pfizer International Metabolic Database). The postal survey data were weighted to ensure that they were representative of the general population.

RESULTS

The mean weighted QoL-AGHDA scores for the general population were 6.2 and 7.1 for men and women, respectively, compared with 13.6 and 15.7 for patients. For both males and females the differences in mean QoL-AGHDA scores between the general population and patients were statistically significant for all age categories (p < 0.01). In the general population the mean QoL-AGHDA score for each category of self-assessed health status increased progressively, indicating a poorer QoL as health status declined.

CONCLUSIONS

This study reports QoL-AGHDA normative values for the population of England and Wales and confirms the extent of QoL impairment in patients with GHD in comparison with the general population.

The Geriatric Depression Scale should be shortened: results of Rasch analysis

BACKGROUND

The purpose of this study was to examine the unidimensionality, item fit, redundancy and differential item functioning (DIF) of the 15-item version of the Geriatric Depression Scale (GDS) in a community sample of 300 Hong Kong Chinese patients with pneumoconiosis.

METHODS

Participants were randomly selected from the case register of the Pneumoconiosis Compensation Fund Board of Hong Kong. A trained research assistant administered the GDS to all participants. A psychiatrist, who was blind to the GDS scores, conducted a structured clinical interview to diagnose depressive disorders according to the Diagnostic and Statistical Manual for Mental Disorders, Version IV (DSM-IV) criteria.

RESULTS

Of the 300 participants, 37 (12.3%) had a DSM-IV diagnosis of depressive disorders. Eleven out of 15 items (73.3%) had INFIT/OUTFIT statistics between 0.7-1.3. Abbreviated versions were created by removal of misfit and redundant items resulting in similar overall performance as the original 15-item GDS. None of the items had significant DIF for age, level of education and cognitive impairment.

CONCLUSIONS

Although the GDS was overall unidimensional, there was evidence of item redundancy indicating that a shortened version would be as adequate as the original version.

Limited efficacy of growth hormone (GH) during transition of GH-deficient patients from adolescence to adulthood: a phase III multicenter, double-blind, randomized two-year trial

CONTEXT

Treatment of GH-deficient adolescents in transition to adulthood remains challenging.

OBJECTIVE

The objective was to assess the safety and efficacy of GH in GH-deficient adolescents in transition.

PATIENTS

Fifty-eight GH-deficient adolescents (mean age, 15.8 +/- 1.8 yr; 33 males) at near completion of their linear growth participated in the study.

INTERVENTION

Baseline studies were done while subjects were on GH. Subjects were retested (insulin-induced hypoglycemia) 4 wk after GH discontinuation and reclassified as persistently GH-deficient or controls (n = 18). GH-deficient subjects were randomized to GH (n = 25, approximately 20 microg/kg.d) or placebo (n = 15).

SETTING

The multicenter study was conducted over a 2-yr period.

MAIN OUTCOMES

Changes in body composition, bone mineral density (BMD), quality of life (QOL), cardiovascular and metabolic markers were measured.

RESULTS

All groups had normal measures of lipid and carbohydrate metabolism, body composition, BMD, cardiac function, muscle strength, and QOL at baseline and after 2 yr. IGF-I concentrations decreased in all, but less so in the GH-group (P = 0.013). There was a greater increase in lean body mass (lesser adiposity) in the GH group than placebo at 12 months, but not at 24 months.

CONCLUSIONS

1) GH-deficient patients properly treated in childhood can have normal BMD, body composition, cardiac function, muscle strength, carbohydrate and lipid metabolism, and QOL when reaching adult height; and 2) continuation of GH therapy for 2 yr did not change these measures as compared to placebo-treated or control subjects. GH-deficient adolescents in good metabolic status at the time of epiphyseal fusion may safely discontinue GH for at least 2 yr. Follow-up is needed to determine whether GH therapy is eventually warranted in subjects treated with GH during childhood.

Cost-effectiveness of proton radiation in the treatment of childhood medulloblastoma

BACKGROUND

Radiation therapy is an important component in the treatment of medulloblastoma; however, in many patients, it is associated with risk of late adverse events. Proton radiation therapy has potential to reduce the risk of adverse events compared with conventional radiation, but it is associated with a higher treatment cost. The objective of the current study was to assess the cost-effectiveness of proton therapy compared with conventional radiation therapy in the treatment of childhood medulloblastoma.

METHODS

The consequences of radiation therapy were evaluated using a Markov simulation model. Children age 5 years with medulloblastoma were followed. The patients were at risk of several types of adverse events, including hearing loss, intelligence quotient (IQ) loss, hypothyroidism, growth hormone deficiency (GHD), osteoporosis, cardiac disease, and secondary malignancies. The patients also were at risk of death and were divided into risk groups for normal death, death due to tumor recurrence, treatment-related cardiac death, treatment-related subsequent tumor death, or treatment-related other death. A review of the literature was conducted to estimate the parameters in the model.

RESULTS

The base-case results showed that proton therapy was associated with 23,600 in cost savings and 0.68 additional quality-adjusted life-years per patient. The analyses showed that reductions in IQ loss and GHD contributed to the greatest part of the cost savings and were the most important parameters for cost-effectiveness.

CONCLUSIONS

The results of the current study indicated that proton radiation therapy can be cost-effective and cost-saving compared with conventional radiation therapy in the treatment of children with medulloblastoma if the appropriate patients are selected for the therapy. However, there have been few long-term follow-up studies, and more much information on the long-term consequences of radiation therapy is needed.

The scoring scheme of the informant questionnaire on cognitive decline in the elderly needs revision: results of rasch analysis

The purpose of this study was to examine the optimal scoring scheme (category use), unidimensionality, item fit, and redundancy of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) in a cohort of Hong Kong Chinese stroke survivors. At 3 months after the index stroke, a research assistant administered the IQCODE to relatives of 284 Chinese patients with acute stroke who were consecutively admitted to a general hospital. A psychiatrist, who was blinded to the IQCODE scores, interviewed all 284 patients and made DSM-IV diagnosis of dementia, which served as the benchmark for judging the performance of IQCODE in screening dementia. The results suggest that the optimal IQCODE scoring scheme has 2 rather than the original 5 categories. Although the IQCODE was unidimensional overall, there was evidence of item redundancy, thus indicating that a shortened version is desirable.

Le questionnaire de qualité de vie QLS-H© : validation de la version française chez les patients avec déficit en hormone de croissance et acquisition des valeurs de référence dans la population générale

The QLS-H(c) (Questions on Life Satisfaction- Hypopituitarism) is new a quality of life (QoL) self-administered questionnaire addressing the complaints of adult patients with growth hormone deficiency. The French version of the QLS-H(c) (16 items) has been psychometrically evaluated during a randomized, open label study comparing two strategies of growth hormone (GH) replacement therapy. Seventy-three patients were included and received an 8-month GH replacement therapy. QoL was explored at baseline, 4 and 8 months using the QLS-H(c) questionnaire and the Nottingham Health Profile (NHP) reference scale. Acceptance of the QLS-H(c) was excellent as 92% of the questionnaires were suitable for analysis. All the items demonstrated good selectivity. The homogeneity of the questionnaire was confirmed (Cronbach's alpha, 0.87). The external validity construct was assessed and confirmed using the NHP scores. Sensitivity to change was confirmed. Following an 8-month replacement therapy, the perception of the QoL assessed with the QLS-H(c) questionnaire was significantly improved, irrespective to the treatment strategy. Finally, redundant items of the questionnaire were removed. As a result, the final version of the QLS-H(c) contained 9 items. In a parallel study, reference data of the QLS-H(c) (9 items) were collected from a representative sample of 989 subjects from the French population. With these reference ranges, algorithms to calculate Z scores adjusted for age and gender were developed as a measure for the deviation of patients' scores from those of the general population, and also to evaluate changes along time. In summary, the French version of the quality of life QLS-H(c) questionnaire is a relevant, validated investigational tool for the evaluation and follow-up of an adult patient with growth hormone deficiency.

Application of Rasch analysis in the development and application of quality of life instruments

This paper discusses recent advances that have been made in the field of psychometrics, specifically, the application of Rasch analysis to the instrument development process. It emphasizes the importance of assessing the fundamental scaling properties of an instrument prior to consideration of traditional psychometric indicators. The paper introduces Rasch analysis and shows how it has been applied in the development of needs-based measures in order to ensure that they provide unidimensional measurement. By ensuring that scales are based on the same measurement model and that they fit the Rasch model it is possible for QoL scores to be compared across diseases by means of cocalibration and item banking.

Decreased quality of life in adult patients with growth hormone deficiency compared with general populations using the new, validated, self-weighted questionnaire, questions on life satisfaction hypopituitarism module

To develop reference ranges for the Questions on Life Satisfaction Hypopituitarism Module (QLS-H), a new quality of life questionnaire for patients with hypopituitarism, data from 8177 adults were collected in France, Germany, Italy, The Netherlands, Spain, the United Kingdom, and the United States QLS-H scores declined with age, were lower in females than males, and differed significantly among countries. From these reference ranges we derived equations for z-scores, which adjust for age, gender, and country. QLS-H results from 957 adults with GH deficiency (GHD) participating in clinical trials were analyzed. At baseline, QLS-H scores were lower in females and differed significantly among countries. QLS-H scores significantly increased after GH treatment (6-8 months), but differences by country persisted. Calculating z-scores for patients eliminated all gender and most country differences. Pooled z-scores (mean +/- SD) from all patients increased from -0.99 +/- 1.39 at baseline to -0.14 +/- 1.30 after GH treatment. Quality of life assessment in adults with GHD requires the use of z-scores to correct for age, gender, and country differences. This approach allows pooling of data from different cohorts and comparison with general populations. QLS-H scores in adults with GHD were significantly decreased at baseline and were almost normalized after 6-8 months of GH therapy.

Rasch analysis of a new stroke-specific outcome scale: the Stroke Impact Scale

OBJECTIVES

To assess multiple psychometric characteristics of a new stroke outcome measure, the Stroke Impact Scale (SIS), using Rasch analysis, and to identify and remove misfitting items from the 8 domains that comprise the SIS.

DESIGN

Secondary analysis of 3-month outcomes for the Glycine Antagonist in Neuroprotection (GAIN) Americas randomized stroke trial.

SETTING

A multicenter randomized trial performed in 132 centers in the United States and Canada.

PARTICIPANTS

A total of 696 individuals with stroke who were community-dwelling and independent prior to acute stroke.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Rasch analysis was performed using WINSTEPS, version 3.31, to evaluate 4 psychometric characteristics of the SIS: (1) unidimensionality or fit (the extent to which items measure a single construct), (2) targeting (the extent to which the items are of appropriate difficulty for the sample), (3) item difficulty (the ordering of items from least to most difficult to perform), and (4) separation (the extent to which the items distinguish distinct levels of functioning within the sample).

RESULTS

(1) Within each domain, most of the items measured a single construct. Only 3 items misfit the constructs and were deleted ("add and subtract numbers," "get up from a chair," "feel emotionally connected") and 2 items ("handle money," "manage money") misfit the combined physical domain. These items were deleted to create SIS, version 3.0. (2) Overall, the items are well targeted to the sample. The physical and participation domains have a wide range of items that capture difficulties that most individuals with stroke experience in physical and role functions, while the memory, emotion, and communication domains include items that capture limitations in the most impaired patients. (3) The order of items from less to more difficult was clinically meaningful. (4) The individual physical domains differentiated at least 3 (high, average, low) levels of functioning and the composite physical domain differentiated more than 4 levels of functioning. However, because difficulties with communication, memory, and emotion were not as frequently reported and difficulties with hand function were more frequently reported, these domains only differentiated 2 (high, low) to 3 (high, average, low) strata of patients. Time from stroke onset to administration of the SIS had little effect on item functioning.

CONCLUSION

Rasch analysis further established the validity of the SIS. The domains are unidimensional, the items have an excellent range of difficulty, and the domain scores differentiated patients into multiple strata. The activities of daily living/instrumental activities of daily living, mobility, strength, composite physical, and participation domains have the most robust psychometric characteristics. The composite physical domain is most able to discriminate difficulty in function in individuals after stroke, while the communication, memory, and emotion domain items only capture limitations in function in the more impaired groups of patients.

Disease activity score for children with juvenile dermatomyositis: reliability and validity evidence

OBJECTIVE

To assess the reliability and validity of the Disease Activity Score (DAS), an instrument used to evaluate children with juvenile dermatomyositis (JDM).

METHODS

Psychometric study of internal consistency, reliability, rater agreement, and the relationship with measures of muscle strength and disability was conducted.

RESULTS

The DAS ratings are internally consistent (reliability = 0.89) and describe a wide range of disease activity. The pediatric rheumatologists in this study agree on the presence of most of the disease indicators. Their disagreements tend to cancel each other, resulting in highly correlated (r = 0.79) overall measures across raters. Estimates of muscle weakness using the DAS and ratings of muscle strength obtained independently from therapists are highly related (r = -0.77), but estimates of disease activity and disability are weakly related (r = 0.20).

CONCLUSION

The DAS exhibits evidence of good reliability and validity. The combination of skin and muscle strength assessments makes this easily administered instrument a useful addition in the evaluation of children with JDM.

Childhood-onset growth hormone (GH) deficiency in adult life

Over the last decade GH replacement therapy for adults has progressed in status from research study to a mainstream clinical indication. An area ripe for further research, however, is the difference between adults who developed GHD before and after completion of growth and puberty. That differences exist, not only in aetiology, but also in phenotype and response to GH therapy is clear. However, whether these differences are intrinsic to the timing of onset of GHD, or related to secondary factors including the method of assessment or dose of GH employed is uncertain. This chapter discusses the current state of knowledge in this area and poses further questions, not only for the researcher attempting to understand the mechanisms underlying these differences, but also for the physician seeking to ameliorate the impact of GHD in patients who acquired GHD in childhood.

Interpretation and validity of changes in scores on the Graves' ophthalmopathy quality of life questionnaire (GO-QOL) after different treatments

OBJECTIVE

The Graves' ophthalmopathy quality of life questionnaire (GO-QOL) is the first instrument available to measure health-related quality of life (HRQL) of patients with Graves' ophthalmopathy. The main objective of this study was to define a minimal clinically important difference (MCID) in score on the GO-QOL that can be considered an important improvement in HRQL by examining changes in GO-QOL scores in patients who subjectively report improvement from their treatment. A secondary objective was to test the longitudinal validity of the GO-QOL, using prespecified hypotheses about expected treatment effects.

DESIGN

A prospective cohort study.

PATIENTS

We included 164 patients who were scheduled for radiotherapy (23), orbital decompression (10 for sight loss, 38 for exophthalmos), eye muscle surgery (31), eyelid lengthening (43) or blepharoplasty (19).

MEASUREMENTS

Patients completed the GO-QOL and three general HRQL questionnaires, before and three or six months after treatment, depending on the performed procedure. Clinical characteristics were collected from the medical records. Mean changes in GO-QOL scores and effect sizes were calculated after different treatments, and in subgroups of responders and nonresponders according to clinical characteristics and according to the patients themselves.

RESULTS

A clinical response to treatment was associated with a change in GO-QOL scores of approximately 10--20 points after major treatments (radiotherapy or decompression), and with a change of approximately 3--10 points after minor surgery (eye muscle surgery, eyelid lengthening, blepharoplasty). Changes in GO-QOL scores of about 6--10 points were considered important improvements by the patients themselves. The direction and amount of change in GO-QOL scores after different treatments were in accordance with our prespecified hypotheses about treatment effects. Effect sizes in the GO-QOL subscales were generally higher than effect sizes of the general HRQL subscales, supporting the longitudinal validity of the GO-QOL.

CONCLUSIONS

As a general guideline, one could consider a mean change of at least 6 points on one or both subscales an important change in daily functioning for patients. For more invasive therapies, a change of at least 10 points is recommended as a minimal clinically important difference.