Growth hormone (GH) replacement in hypopituitary adults with GH deficiency evaluated by a utility-weighted quality of life index: a precursor to cost-utility analysis

Metabolic and quality of life effects of growth hormone replacement in patients with TBI and AGHD: A pilot study

OBJECTIVE

Traumatic brain injury (TBI), a common cause of adult growth hormone deficiency (AGHD), affects 20% of Veterans returning from Iraq and Afghanistan (OEF/OIF/OND). Growth hormone replacement therapy (GHRT) improves quality of life (QoL) in AGHD but remains unexplored in this population. This pilot, observational study investigates the feasibility and efficacy of GHRT in AGHD following TBI.

DESIGN

In this 6-month study of combat Veterans with AGHD and TBI starting GHRT (N = 7), feasibility (completion rate and rhGH adherence) and efficacy (improvements in self-reported QoL) of GHRT were measured (primary outcomes). Secondary outcomes included body composition, physical and cognitive function, psychological and somatic symptoms, physical activity, IGF-1 levels and safety parameters. It was hypothesized that participants would adhere to GHRT and that QoL would significantly improve after six months.

RESULTS

Five subjects (71%) completed all study visits. All patients administered daily rhGH injections, 6 (86%) of whom consistently administered the clinically-prescribed dose. While QoL demonstrated numeric improvement, this change did not reach statistical significance (p = 0.17). Significant improvements were observed in total lean mass (p = 0.02), latissimus dorsi strength (p = 0.05), verbal learning (Trial 1, p = 0.02; Trial 5, p = 0.03), attention (p = 0.02), short-term memory (p = 0.04), and post-traumatic stress disorder (PTSD) symptoms (p = 0.03). Body weight (p = 0.02) and total fat mass (p = 0.03) increased significantly.

CONCLUSION

GHRT is a feasible and well-tolerated intervention for U.S. Veterans with TBI-related AGHD. It improved key areas impacted by AGHD and symptoms of PTSD. Larger, placebo-controlled studies testing the efficacy and safety of this intervention in this population are warranted.

'Mapping' Health State Utility Values from Non-preference-Based Measures: A Systematic Literature Review in Rare Diseases

BACKGROUND

The use of patient-reported outcome measures (PROMs) to monitor the effects of disease and treatment on patient symptomatology and daily life is increasing in rare diseases (RDs) (i.e. those affecting less than one in 2000 people); however, these instruments seldom yield health state utility values (HSUVs) for cost-utility analyses. In such a context, 'mapping' allows HSUVs to be obtained by establishing a statistical relationship between a 'source' (e.g. a disease-specific PROM) and a 'target' preference-based measure [e.g. the EuroQol-5 Dimension (EQ-5D) tool].

OBJECTIVE

This study aimed to systematically review all published studies using 'mapping' to derive HSUVs from non-preference-based measures in RDs, and identify any critical issues related to the main features of RDs, which are characterised by small, heterogeneous, and geographically dispersed patient populations.

METHODS

The following databases were searched during the first half of 2019 without time, study design, or language restrictions: MEDLINE (via PubMed), the School of Health and Related Research Health Utility Database (ScHARRHUD), and the Health Economics Research Centre (HERC) database of mapping studies (version 7.0). The keywords combined terms related to 'mapping' with Orphanet's list of RD indications (e.g. 'acromegaly') in addition to 'rare' and 'orphan'. 'Very rare' diseases (i.e. those with fewer than 1000 cases or families documented in the medical literature) were excluded from the searches. A predefined, pilot-tested extraction template (in Excel^®) was used to collect structured information from the studies.

RESULTS

Two groups of studies were identified in the review. The first group (n = 19) developed novel mapping algorithms in 13 different RDs. As a target measure, the majority used EQ-5D, and the others used the Short-Form Six-Dimension (SF-6D) and 15D; most studies adopted ordinary least squares (OLS) regression. The second group of studies (n = 9) applied previously published algorithms in non-RDs to comparable RDs, mainly in the field of cancer. The critical issues relating to 'mapping' in RDs included the availability of very few studies, the relatively high number of cancer studies, and the absence of research in paediatric RDs. Moreover, the reviewed studies recruited small samples, showed a limited overlap between RD-specific and generic PROMs, and highlighted the presence of cultural and linguistic factors influencing results in multi-country studies. Lastly, the application of existing algorithms developed in non-RDs tended to produce inaccuracies at the bottom of the EQ-5D scale, due to the greater severity of RDs.

CONCLUSIONS

More research is encouraged to develop algorithms for a broader spectrum of RDs (including those affecting young children), improve mapping study quality, test the generalisability of algorithms developed in non-RDs (e.g. HIV) to rare variants or evolutions of the same condition (e.g. AIDS wasting syndrome), and verify the robustness of results when mapped HSUVs are used in cost-utility models.

In primary care, is measuring free-thyroxine plus thyroid-stimulating hormone to detect hypopituitarism cost-effective? A cost utility analysis using Markov chain models

OBJECTIVE

We examined whether it is cost-effective to measure free thyroxine (FT4) in addition to thyrotropin (thyroid-stimulating hormone (TSH)) on all requests for thyroid function tests from primary care on adult patients.

BACKGROUND

Hypopituitarism occurs in about 4 people per 100 000 per year. Loss of thyrotropin (TSH) secretion may lead to secondary hypothyroidism with a low TSH and low FT4, and this pattern may help to diagnose hypopituitarism that might otherwise be missed.

DESIGN

Markov model simulation.

PRIMARY OUTCOME MEASURE

Incremental cost-effectiveness ratio (ICER), the ratio of cost in pounds to benefit in quality-adjusted life years of this strategy.

RESULTS

The ICER for this strategy was £71 437. Factors with a large influence on the ICER were the utilities of the treated hypopituitary state, the likelihood of going to the general practitioner (GP) and of the GP recognising a hypopituitary patient. The ICER would be below £20 000 at a cost to the user of an FT4 measurement of £0.61.

CONCLUSION

With FT4 measurements at their present cost to the user, routine inclusion of FT4 in a thyroid hormone profile is not cost-effective.

Health-related quality of life in pituitary diseases

In the last 15 years, worse health-related quality of life (QoL) has been reported in patients with pituitary diseases compared with healthy individuals. Different QoL questionnaires have shown incomplete physical and psychological recovery after therapy. Residual impairments often affect QoL even long-term after successful treatment of pituitary adenomas. In this article, knowledge of factors that affect QoL in pituitary diseases is reviewed. The focus is on 5 pituitary diseases: Cushing syndrome, acromegaly, prolactinomas, nonfunctioning pituitary adenomas, and hypopituitarism.

Cost effectiveness of proton versus photon radiation therapy with respect to the risk of growth hormone deficiency in children

BACKGROUND

Proton therapy in pediatrics may improve the risk/benefit profile of radiotherapy at a greater upfront financial cost, but it may prove to be cost effective if chronic medical complications can be avoided. Tools to assist with decision making are needed to aid in selecting pediatric patients for protons, and cost-effectiveness models can provide an objective method for this.

METHODS

A Markov cohort-simulation model was developed to assess the expected costs and effectiveness for specific radiation doses to the hypothalamus with protons versus photons in pediatric patients. Costing data included cost of investment and the diagnosis and management of growth hormone deficiency. Longitudinal outcomes data were used to inform risk parameters for the model. With costs in 2012 US dollars and effectiveness measured in quality-adjusted life years, incremental cost-effectiveness ratios were used to measure outcomes.

RESULTS

Proton therapy was cost effective for some scenarios based on the difference in hypothalamic sparing. Although some scenarios were not cost effective, others were not only cost effective for proton therapy but also demonstrated that protons were cost saving compared with photons.

CONCLUSIONS

The current results provide the first evidence-based guide for identifying children with brain tumors who may benefit the most from proton therapy with respect to endocrine dysfunction. Proton therapy may be more cost effective for scenarios in which radiation dose to the hypothalamus can be spared, but protons may not be cost effective when tumors are involving or directly adjacent to the hypothalamus if there is a high dose to this structure.

An audit of growth hormone replacement for GH-deficient adults in Scotland

OBJECTIVE

Guidelines on the clinical use of growth hormone therapy in adults were issued by the UK National Institute for Clinical Excellence (NICE) in August 2003. We conducted a retrospective clinical audit on the use of growth hormone (GH) in Scotland to evaluate the use of these guidelines and their impact on clinical practice. The audit had two phases. In phase I, the impact of NICE criteria on specialist endocrine practice in starting and continuing GH replacement was assessed. In phase II, the reasons why some adults in Scotland with growth hormone deficiency were not on replacement therapy were evaluated.

METHODS

A retrospective cross-sectional case note review was carried out of all adult patients being followed up for growth hormone deficiency during the study period (1 March 2005 to 31 March 2008). Phase I of the audit included 208 patients and phase II 108 patients.

RESULTS

Sellar tumours were the main cause of GH deficiency in both phases of the audit. In phase I, 53 patients (77%) had an AGHDA-QoL score >11 documented before commencing GH post-NICE guidance, compared with 35 (25%) pre-NICE guidance. Overall, only 39 patients (18%) met the full NICE criteria for starting and continuing GH (pre-NICE, 11%; post-NICE, 35%). Phase II indicated that the main reasons for not starting GH included perceived satisfactory quality of life (n = 47, 43%), patient reluctance (16, 15%) or a medical contraindication (16, 15%).

CONCLUSIONS

Although the use of quality of life assessments has increased following publication of the NICE guidelines, most adults on GH in Scotland did not fulfil the complete set of NICE criteria. The main reason for not starting GH therapy in adult GH-deficient patients was perceived satisfactory quality of life.

Improving Quality of Life in Patients with Pituitary Tumours

Evaluation of health-related quality of life (QoL) in people with pituitary tumours has received much attention over the last 10-15 years. Most of them show impaired QoL, but little is known about how to prevent impairment or how to improve QoL. Our aim is to review what is known about QoL in pituitary tumours patients and to highlight the areas worth improving, for the patient's well being. The article has four sections: acromegaly, Cushing's syndrome, prolactinomas and non-functioning adenomas. Control of comorbidities is usually an important factor to prevent QoL impairment; however, each disease has specific characteristics that should be properly addressed in order to obtain full patient recovery after successful therapy.

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.

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.

Quality of life in patients with pituitary tumors

PURPOSE OF REVIEW

Quality of life (QoL) is impaired in patients with pituitary tumors, even after biochemical cure. However, it is not usually assessed in daily practice. The aim of this study is to highlight recent findings on QoL in the different types of pituitary adenomas and hypopituitarism.

RECENT FINDINGS

Patients with acromegaly or Cushing's syndrome have the greatest impairment of QoL, and concomitant hypopituitarism worsens it further. The use of disease-generated QoL questionnaires allows dimensions specifically affected in that disease to be addressed and these dimensions are more sensitive to change after successful therapy; in some cases, improvement in patients' sense of well-being has been shown despite no hormonal change, indicating that evaluation of QoL is not such a soft end-point as thought by some.

SUMMARY

Systematic evaluation of QoL in patients with pituitary diseases provides information not always contemplated by hormonal and routine clinical evaluation; this allows detection of not often contemplated health problems, which may then be approached and treated, improving the care provided to these patients.

[Growth hormone deficiency in adulthood: how to diagnose and when to treat?]

Adult growth hormone deficiency (AGHD) is a well-established clinical entity with heterogeneous characteristics, in which the main causes are hypothalamus-pituitary tumors and/or their treatment. The diagnosis of ADGH should be considered in patients with a prior history of childhood-onset GH deficiency or a history of organic hypothalamus-pituitary disease. In these patients diagnosis is performed biochemically by provocative tests of GH secretion, once the measurement of the biological markers for GH action:IGF-l and IGFBP-3 levels, can be in the normal range in an important percentage of AGHD patients. The current treatment using an initial low dose of hrGH followed by individualised dose titration adjusted according to serum IGF-1 levels, leads to similar beneficial effects with less incidence of side effects, improved tolerance to treatment and a lower stable GH dose as compared to hrGH replacement therapy based on body weight or body surface area. As some patients might not profit from hrGH therapy, the potential beneficial effects of hrGH replacement therapy should be analyzed on individualized basis. Alternative available therapies with similar efficacy should be taken into consideration. Physical activity may improve body compostion, cardiovascular perfomance and well being in ADGH subjects not submitted to hrGH treatment. An important target of hrGH replacement therapy is its impact on quality of life, leading to social and professional improvement. Epidemiological evidence points to a decreasing life expectancy in ADGH patients but data regarding the impact of hrGH replacement on life expectancy are still lacking.