The impact of iron overload and its treatment on quality of life: results from a literature review

Geographical variations in current clinical practice on transfusions and iron chelation therapy across various transfusion-dependent anaemias

BACKGROUND AND OBJECTIVES

Many patients with chronic anaemia require blood transfusions as part of their treatment regimen. As a result, iron overload will inevitably develop if not adequately managed by iron chelation therapy. There are many guidelines relating to transfusion and chelation practices for patients with transfusion-dependent anaemia; however, there is a lack of information on how treatment practices differ around the world. The objective of this manuscript is to highlight key features of current transfusion and chelation management, including similarities and differences across various anaemias and between geographical regions worldwide.

MATERIALS AND METHODS

Data collected at study entry to the multicentre Evaluation of Patients' Iron Chelation with Exjade (EPIC) study, which recruited 1,744 patients with a variety of transfusion-dependent anaemias across 23 countries from three geographic regions, were assessed. These analyses compared transfusion and chelation treatment prior to the start of study treatment, together with iron burden assessed at study entry by serum ferritin, liver iron concentration and labile plasma iron levels.

RESULTS AND CONCLUSIONS

Data show that transfusion and iron chelation practices differ between anaemias and between geographical regions; this may be linked to availability and accessibility of transfusion and chelation therapy, patients' compliance, physicians' attitudes, costs and use of treatment guidelines. Approximately 60% of these transfusion-dependent patients were severely iron overloaded with a serum ferritin level over 2,500 ng/mL, indicating that the risks of iron burden may have been underestimated and current iron chelation therapy, if considered, may not have been adequate to control iron burden.

Psychometric properties of the Specific Thalassemia Quality of Life Instrument for adults

BACKGROUND

No specific questionnaire has been developed to assess the health-related quality of life of thalassemia patients. Thus, the main objective of this study was to develop, according to psychometric standards, a self-administered Specific Thalassemia Quality of Life Instrument (STQOLI) for adult patients.

METHODS

First, a qualitative phase was conducted to generate items and identify domains using the critical analysis incident technique and a literature review. A list of easily comprehensible, non-redundant items was defined using the Delphi technique and a pilot study on ten thalassemia patients. This phase involved both patients and experts. The second step was a quantitative validation phase comprising a study of 128 thalassemia patients in a single hospital. It was designed to select items, identify dimensions, and measure reliability and internal and concurrent validity. The psychometric and scaling properties of the proposed 41-item Specific Thalassemia Quality of Life Instrument were then assessed among patients recruited from the Thalassemia Unit at the General Hospital of Nikaia, Greece.

RESULTS

The final questionnaire had 41 items comprising four main domains and one global item about general health. The factorial structure was satisfactory (loading > 0.40 on each factor of the four domains for all items). Interscale correlations ranged from 0.06 to 0.78, Cronbach's α-coefficients were 0.78 for the psychosocial domain, 0.77 for the chelation domain, 0.72 for the transfusion domain, 0.81 for the disease and symptoms domain, and 0.840 for the total score of the questionnaire.

CONCLUSION

The 41-item Specific Thalassemia Quality of Life Instrument seems to be a valid tool for assessing health-related quality of life for patients with thalassemia. More research is needed to explore the universal properties of the questionnaire.

A new tool for the assessment of satisfaction with iron chelation therapy (ICT-Sat) for patients with β-thalassemia major

BACKGROUND

High satisfaction with iron chelation is a major determinant for adherence to ICT in beta-thalassaemia major (β-TM) patients. In this study, a new tool to assess different domains of satisfaction for available forms of ICT was developed and validated. The impact of patients' satisfaction with ICT has been tested.

METHODS

Items were generated via focus groups and a preliminary version with 24 items (ICT-Sat) with an additional item for treatment preference and a knowledge questionnaire (KQ) was developed. 170 β-TM patients from three Thalassaemia centers in Egypt, aged 2-32 years received three questionnaires to fill in; the new ICT-Sat, a KQ, and a previously validated tool for satisfaction with ICT (SICT) and retested 4-6 weeks later to ensure re-test reliability. Type of chelation, drug related adverse events, compliance with ICT, and serum ferritin level (SF) during the year prior to the study as well as available cardiac T2*data were recorded.

RESULTS

One hundred and fifty two β-TM patients completed all questionnaires; median age was 12 years. The final 15 remaining ICT-Sat items, yielding to four domain scores, explained 70.6% of the total variance. The "perceived effectiveness" and "fear and worries" domains of the ICT-Sat correlated significantly with the domains "perceived effectiveness" and "acceptance" of the SICT. Patients treated with oral ICT were more satisfied with perceived effectiveness, and their side effects.

CONCLUSIONS

A new clinically based ICT-Sat tool was developed and revealed good psychometric characteristics. Adherence to ICT was better correlated with "perceived effectiveness" and SF level.

Phosphoproteomic analysis of apoptotic hematopoietic stem cells from hemoglobin E/β-thalassemia

Background

Hemoglobin E/β-thalassemia is particularly common in Southeast Asia and has variable symptoms ranging from mild to severe anemia. Previous investigations demonstrated the remarkable symptoms of β-thalassemia in terms of the acceleration of apoptotic cell death. Ineffective erythropoiesis has been studied in human hematopoietic stem cells, however the distinct apoptotic mechanism was unclear.

Methods

The phosphoproteome of bone marrow HSCs/CD34⁺ cells from HbE/β-thalassemic patients was analyzed using IMAC phosphoprotein isolation followed by LC-MS/MS detection. Decyder MS software was used to quantitate differentially expressed proteins in 3 patients and 2 normal donors. The differentially expressed proteins from HSCs/CD34⁺ cells were compared with HbE/β-thalassemia and normal HSCs.

Results

A significant change in abundance of 229 phosphoproteins was demonstrated. Importantly, the analysis of the candidate proteins revealed a high abundance of proteins that are commonly found in apoptotic cells including cytochrome C, caspase 6 and apoptosis inducing factors. Moreover, in the HSCs patients a significant increase was observed in a specific type of phosphoserine/threonine binding protein, which is known to act as an important signal mediator for the regulation of cell survival and apoptosis in HbE/β-thalassemia.

Conclusions

Our study used a novel method to investigate proteins that influence a particular pathway in a given disease or physiological condition. Ultimately, phosphoproteome profiling in HbE/β-thalassemic stem cells is an effective method to further investigate the cell death mechanism of ineffective erythropoiesis in β-thalassemia. Our report provides a comprehensive phosphoproteome, an important resource for the study of ineffective erythropoiesis and developing therapies for HbE/β-thalassemia.

Which psychosocial factors are related to chelation adherence in thalassemia? A systematic review

Good adherence to iron chelation therapy in thalassemia is crucial. Although there is evidence that adherence is related to regimen factors, there has been less emphasis on the relationship between psychosocial (psychological, demographic and social) factors and adherence. We present a systematic review of psychosocial correlates of chelation adherence in thalassemia. Nine studies met the inclusion criteria. Information was extracted regarding the study characteristics and the relationship between psychosocial factors and chelation adherence. Methodological quality was rated. The studies took place in a range of countries, were mostly cross sectional in design, and examined adherence to deferoxamine (DFO) only. Sample sizes ranged from 15 to 1573. A variety of psychosocial variables were examined. Definitions of adherence varied between studies and non adherence rates were also variable (9 to 66%). Older age was consistently associated with lower levels of chelation adherence. There were few other consistent findings. The methodological quality of studies was variable. There is a need for more methodologically sophisticated and theoretically informed studies on psychosocial correlates of chelation adherence. We offer specific suggestions.

An instrument assessing satisfaction with iron chelation therapy: Psychometric testing from an open-label clinical trial

INTRODUCTION

The Satisfaction with Iron Chelation Therapy (SICT) instrument was developed based on a literature review, in-depth patient and clinician interviews, and cognitive debriefing interviews. An, open-label, single arm, multicenter trial evaluating the efficacy and safety of deferasirox in patients diagnosed with transfusion-dependent iron overload, provided an opportunity to assess the psychometric measurement properties of the instrument.

METHODS

Psychometric analyses were performed using data at baseline from 273 patients with a range of transfusion-dependent iron overload conditions who were participating in a multinational study. Responsiveness was further evaluated for all patients who also had subsequent satisfaction domain scores collected at week 4.

RESULTS

Baseline SICT domain scores had acceptable floor and ceiling effects and internal consistency reliability (Cronbach's alpha: 0.75-0.85). Item discriminant and item convergent validity were both excellent although one item in each analysis did not meet the specified criterion. Small to moderate correlations were observed between SICT and Short Form 36 Health Survey (SF-36) domain scores. Patients with the highest levels of serum ferritin at baseline (>3100 ng/mL) were the least satisfied about the Perceived Effectiveness of ICT and vice versa. Satisfaction improved in all patients, although there were no clear differences observed between groups of patients defined according to changes in serum ferritin levels from baseline to week 4 (stable, improved, or worsened).

CONCLUSIONS

The SICT domains are reliable and valid. Further testing using a more specific criterion (such as assessing patient global ratings of change in satisfaction domains that correspond to the SICT domains) could help to establish with greater confidence the responsiveness of the instrument.

Socio-psychological impact of infused iron chelation therapy with deferoxamine in metropolitan France: ISOSFER study results

Deferoxamine (DFO) is an iron chelator used to treat iron overload in patients receiving chronic blood transfusions, and is usually administered as overnight subcutaneous infusions. ISOSFER was a prospective, observational, cross-sectional study conducted in metropolitan France that evaluated patient characteristics, quality of life (QoL), compliance and patient satisfaction with DFO monotherapy. Of 70 patients with either thalassemia, sickle cell disease or myelodysplastic syndromes, 30% were 'satisfied' or 'very satisfied' with DFO. Patients' SF-36 scores were lower than those of the general French population, and lower among patients with comorbidities and those dissatisfied with treatment. Although 72% of patients had good compliance to DFO, 57% reported missing at least one infusion in the previous month, and 82% of patients expressed a preference for oral therapy. These results suggest that QoL is severely compromised in patients receiving DFO, and that compliance is not optimal.

Economic burden of beta-thalassemia/Hb E and beta-thalassemia major in Thai children

Background

Hemoglobin E beta-thalassemia (β-thalassemia/Hb E) has a variable severity, and the cost of treatment has not been well studied. The aim of this study was to analyze the societal cost of caring for children with β-thalassemias in Thailand. The study was designed as a prevalence-based cost-of-illness analysis in a societal perspective. Medical records from three public hospitals of children aged 2-18 years with β-thalassemia/Hb E and homozygous β-thalassemia were reviewed for direct medical cost determination. For direct non-medical cost and indirect cost, a family member was interviewed.

Findings

It was found that 201 patients with β-thalassemia/Hb E (91%) and homozygous β-thalassemia (9%) were recruited for this study. Ninety-two (46%) were severe thalassemia and 109 (54%) were mild to moderate severity. The annual average cost of treatment was US$950; 59% was direct medical cost, 17% direct non-medical cost, and 24% indirect cost. The costs were differentiated by some potential predictors. Significant predictor variables were: hospital, health insurance scheme, blood transfusion pattern, and iron chelation drug use.

Conclusions

The average annual cost per patient was calculated, and the cost model was estimated. These would be applied for national planning, economic evaluation of treatment and prevention interventions, and budget impact analysis.

Factors affecting health-related quality of life in Thai children with thalassemia

Background

Knowledge of the factors associated with health-related quality of life (HRQOL) among patients with thalassemia is essential in developing more suitable clinical, counseling, and social support programs to improve treatment outcomes of these patients. In light of the limited research in this area, this study aims to examine factors associated with HRQOL among children and adolescents with thalassemia in Thailand.

Methods

A cross-sectional survey was conducted in three selected hospitals in Thailand during June to November 2006. PedsQL™ 4.0 Generic Core Scale (Thai version) was used to assess HRQOL in 315 thalassemia patients between 5 and 18 years of age. Other related clinical characteristics of the patients were collected via medical record review.

Results

The mean (SD) of the total summary score was 76.67 (11.40), while the means (SD) for the Physical Health Summary score and Psychosocial Health Summary score were 78.24 (14.77) and 75.54 (12.76), respectively. The school functioning subscale scored the lowest, with a mean of 67.89 (SD = 15.92). The following factors significantly affected the HRQOL of the patients: age; age at onset of anemia and age at first transfusion; pre-transfusion hemoglobin (Hb) level; receiving a blood transfusion during the previous three months; and disease severity. In addition, iron chelation therapy had a significant negative effect on HRQOL in the school functioning subscale. In contrast, serum ferritin level, frequency of blood transfusions per year, and gender were not significantly related to HRQOL among these patients. The results from multivariate analysis also confirmed these findings.

Conclusions

To improve HRQOL of thalassemia patients, suitable programs aimed at providing psychosocial support and a link between the patient, school officials, the family and the physician are important, especially in terms of improving the school functioning score. The findings also confirmed the importance of maintaining a pre-transfusion Hb level of at least 9-10.5 g/dL. In addition, special care and attention should be given to patients with a severe condition, and those who are receiving subcutaneous iron chelation therapy.

Cost effectiveness of deferasirox compared to desferrioxamine in the treatment of iron overload in lower-risk, transfusion-dependent myelodysplastic syndrome patients

OBJECTIVE

The study evaluated the cost effectiveness of deferasirox (Exjade * ) compared to non-proprietary desferrioxamine (DFO) for the control of transfusional iron overload in lower risk myelodysplastic syndromes (MDS) patients. A UK National Health Service perspective was adopted.

METHODS

Recent clinical evidence has demonstrated the efficacy and safety of deferasirox in transfusion-dependent MDS patients with elevated serum ferritin levels. An economic model was used to extrapolate the clinical benefits of iron chelation therapy (ICT) in a cohort of lower risk MDS patients. Costs for drug acquisition, drug administration and monitoring, and quality of life (utility) outcomes associated with mode of drug administration were derived from a variety of sources. The incremental cost per QALY gained for deferasirox was estimated. Costs and outcomes were discounted at 3.5% in line with UK standards.

RESULTS

The base-case cost effectiveness of deferasirox versus DFO was estimated to be £20,822 per QALY gained, the key driver being the additional quality of life benefits associated with a simpler mode of administration for deferasirox. A mean survival benefit for both forms of ICT of 4.5 years was estimated. The results were sensitive to drug dose, days of DFO administration, and patient weight.

CONCLUSIONS

In the UK, a cost per QALY below £20,000-30,000 is considered cost effective. Hence, the results from this economic analysis suggest deferasirox is cost effective in lower risk, transfusion-dependent, MDS patients. Limitations with the analysis include a lack of comparative randomised controlled trial evidence, in particular to differentiate survival and clinical outcomes for deferasirox and DFO.

A time-cost augmented economic evaluation of oral deferasirox versus infusional deferoxamine [corrected] for patients with iron overload in South Korea

OBJECTIVES

This study aims to conduct an economic evaluation of oral deferasirox (DSX) compared with infusional deferoxamine (DFO) in patients with transfusional iron overload.

METHODS

Depending on the methods for measuring time-cost and convenience associated with the mode of administration, either cost-utility analysis or cost-effectiveness analysis was undertaken. The difference in compliance rate between DSX and DFO was applied.

RESULTS

Although the drug cost of DSX was US$124,070 higher than that of DFO (US$96,039 vs. US$220,199), all other costs were lower in patients with DSX than in patients with DFO. In the cost-utility analysis, DSX resulted in US$3197 savings with a gain of 2.63 quality-adjusted life-years per patient. The result of the cost-effectiveness analysis also showed that DSX dominated DFO.

CONCLUSIONS

With a considerable improvement in convenience and injection time rather than efficacy, DSX is considered as a dominant therapy for patients with iron overload.

Satisfaction and adherence in patients with iron overload receiving iron chelation therapy as assessed by a newly developed patient instrument

OBJECTIVES

This study assesses satisfaction with iron chelation therapy (ICT) based on a reliable and valid instrument, and explores the relationship between satisfaction and adherence to ICT.

METHODS

Patients in the USA and UK completed a new "Satisfaction with ICT" (SICT) instrument consisting of 28 items, three pertaining to adherence. Simple and multivariate regression analyses assessed the relationship between satisfaction with different aspects of ICT and adherence.

RESULTS

First assessments of the SICT instrument indicate its validity and reliability. Recommended thresholds for internal consistency, convergent validity, discriminant validity, and floor and ceiling effects were met. A number of variables were identified in the simple linear regression analyses as significant predictors of "never thinking about stopping ICT," a proxy for adherence. These significant variables were entered into the multivariate model to assess the combined factor effects, explaining 42% of the total variance of "never thinking about stopping ICT." A significant and positive relationship was demonstrated between "never thinking about stopping ICT" and age (P = 0.04), Perceived Effectiveness of ICT (P = 0.003), low Burden of ICT (P = 0.002), and low Side Effects of ICT (P = 0.01).

CONCLUSIONS

The SICT is a reliable and valid instrument which will be useful in ICT clinical trials. Furthermore, the administration of ICT by slow subcutaneous infusion negatively impacts on satisfaction with ICT which was shown to be a determinant of adherence. This points to the need for new more convenient and less burdensome oral iron chelators to increase adherence, and ultimately to improve patient outcomes.

Quality of life in patients with transfusion-dependent thalassemia after hematopoietic SCT

In this cross-sectional study, we compared the quality of life (QOL) in transfusion-dependent thalassemic patients who survived matched sibling hematopoietic SCT (HSCT, n=24) with patients treated conventionally with transfusion and iron chelation (n=74). WHOQOL-BREF(HK) and PedsQL questionnaires were administered to patients aged >18 years and 5-12 years, respectively. Patients aged 12-18 years received both questionnaires. WHOQOL-BREF(HK) revealed post transplant patients rated overall health better than those treated conventionally (score 3.67 vs 3.06, P=0.01). They are less dependent on medical aids (3.87 vs 2.96, P=0.006), having higher activity level (4.00 vs 3.36, P=0.026) and better personal relationships (4.13 vs 3.69, P=0.014). Physical health domain score was better (75.20 vs 63.94, P=0.007). These differences remained significant after adjustment for comorbidities. PedsQL revealed post transplant patients rated better for running (3.53 vs 2.72, P=0.001) and sports (3.20 vs 2.64, P=0.038), even after adjustment for comorbidities, but were less satisfied for school absence to attend hospital (2.53 vs 3.29, P=0.03). Post transplant patients were significantly more likely to consider marriage (100 vs 75.7%, P=0.033), but not childbearing (66.7 vs 51.4%, P=0.28). In conclusion, transplanted thalassemic patients enjoy better QOL, mainly in physical health, compared with conventionally treated patients. This information is important to patients considering HSCT.

Iron chelation therapy: clinical effectiveness, economic burden and quality of life in patients with iron overload

INTRODUCTION

This study of UK patients examines clinical, health-related quality of life (HRQOL) and economic outcomes associated with iron chelation therapy (ICT). Desferrioxamine (DFO) (Desferal; Novartis, Switzerland) and Deferiprone (Ferriprox; Apotex, Canada) are ICTs used to treat iron overload. DFO requires 8-to 12-hour infusions a minimum of five times per week. Deferiprone is administered in an oral daily regimen. Although pharmacologically efficacious, clinical effectiveness of ICT within the real-world setting is yet to be fully elucidated.

METHODS

A naturalistic cohort study of 60 patients (beta-thalassaemia, n=40; sickle cell disease, n=14; myelodysplastic syndromes, n=6; 63% female) receiving ICT in four UK treatment centres was conducted. Serum ferritin level data were abstracted from medical charts. Compliance, HRQOL, satisfaction and resource utilisation data were collected from interviews. Maximum ICT costs were estimated using the resource utilisation data associated with DFO.

RESULTS

Mean serum ferritin levels, generally, remained elevated despite ICT. Compliance was suboptimal and HRQOL scores were lower than population norms. The total estimated mean weighted annual per-patient cost of DFO treatment was approximately pound19,000. DFO-related equipment, DFO drug, and home healthcare were estimated to account for 43%, 19% and 24% of costs, respectively. Other more minor components of total annual costs were for in-patient infusions, ICT home delivery services and monitoring costs.

CONCLUSION

Generally, patients are not achieving target serum ferritin thresholds despite chronic treatment for iron overload. ICT appears to negatively impact HRQOL; compliance with ICT is poor; and, in the case of DFO, treatment costs well exceed the cost of DFO alone. These results suggest that current ICT in the real-world setting is suboptimal with respect to various clinical, HRQOL and economic outcomes.

Cost-utility analysis of deferasirox compared to standard therapy with desferrioxamine for patients requiring iron chelation therapy in the United Kingdom

OBJECTIVE

The primary objective of the study was to evaluate the cost-utility of deferasirox (Exjade) compared to standard therapy using desferrioxamine (Desferal) for the control of iron overload in patients receiving frequent blood transfusions. The perspective adopted was that of the National Health Service in the UK.

METHODS

Phase II/III clinical trials have shown deferasirox in the recommended doses of 20-30 mg/kg per day to have similar efficacy to desferrioxamine at equivalent doses in the control of chronic iron overload. The main difference between them is in the mode of administration. Desferrioxamine is administered parenterally as a slow subcutaneous infusion typically infused 8-12 hours a day for 5-7 days a week. In comparison, deferasirox provides 24 hour chelation via a once daily oral tablet dispersed in water or juice. An excel based economic model was developed to evaluate the annual healthcare costs and quality of life, or utility, benefits associated with differences in mode of administration, using beta-thalassaemia as the reference case. A community utility study using time trade-off methods was performed to determine utility outcomes associated with iron chelation therapy (ICT) mode of administration.

RESULTS

In the reference case (patient mean weight 42 kg), deferasirox 'dominated' desferrioxamine, i.e. resulted in lower net costs and higher quality adjusted life years (QALYs). Drug dose and cost is patient weight related. Incremental cost per QALY gained was pound 7775 for patients with a mean weight of 62 kg.

CONCLUSIONS

The cost-utility analysis did not take drug compliance into account. However, Deferasirox is cost-effective compared to standard iron chelation therapy with desferrioxamine, due to the cost and quality of life benefits derived from a simpler and more convenient oral mode of administration.

Quality of life related to oral versus subcutaneous iron chelation: a time trade-off study

OBJECTIVE

To investigate the utility associated with subcutaneous infusion (deferoxamine) compared with once-daily oral administration (deferasirox) of iron chelation therapy.

METHODS

Interviews using the time trade-off technique were used to estimate preferences (utility) for health states by finding the point at which respondents were indifferent between a longer but lower quality of life (QoL) and a shorter time in full health. Participants (n = 110) were community-based, 51% women, median age 35 years, from four regions in Sydney, Australia. Respondents rated three health states involving equal outcomes for people with thalassemia but with different treatment modalities for iron chelation; an "anchor state" describing a patient receiving iron chelation without administration mode specified, anchor state plus iron chelation via subcutaneous infusion, and anchor state plus iron chelation through once-daily oral medication.

RESULTS

On an interval scale between 0 (death) and 1 (full health), median (interquartile range) utility of 0.80 (0.65-0.95) for the anchor state, 0.66 (0.45-0.87) for subcutaneous infusion, and 0.93 (0.80-0.97) for once-daily oral administration was obtained. The mean (median) difference of 0.23 (0.27) between the two treatments was statistically significant (Wilcoxon-signed rank test, P < 0.001). Subcutaneous infusion was associated with a mean (median) utility 0.13 (0.14) lower than the anchor state (P < 0.001), and once-daily oral treatment had a utility 0.10 (0.13) higher (P < 0.001).

CONCLUSION

Community respondents associate oral administration of an iron chelator such as deferasirox with enhanced QoL compared with subcutaneous treatment. Assuming equal safety and efficacy, QoL gains from once-daily oral treatment compared with subcutaneous infusion are significant.