Type of intervention Treatment. Economic study type Cost-effectiveness analysis.

Transcription

1 Costs and consequences of botulinum toxin type A use: management of children with cerebral palsy in Germany Ruiz F J, Guest J F, Lehmann A, Davie A M, Guttler K, Schluter O, Dreiss G Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The use of botulinum toxin injections for the treatment of children with cerebral palsy was compared with no such injections. No further details of the medical treatment were provided. Type of intervention Treatment. Economic study type Cost-effectiveness analysis. Study population The study population comprised children with cerebral palsy who were eligible to receive botulinum toxin. No further inclusion or exclusion criteria were reported. Setting The setting was tertiary care, the Seepark Hospital (Debstedt, Germany) which is a tertiary referral centre for managing children with cerebral palsy and spasticity. The economic study was carried out in Germany. Dates to which data relate The dates during which the effectiveness data were collected were not reported explicitly. Data for the botulinum toxin group were collected retrospectively on patients treated at the centre after Data for the control group were collected retrospectively from case notes made from 1990 to Much of the data on resource use and costs were derived during the fiscal year 2001/02. The authors did not report dates for cost data that were derived from earlier sources. All the cost data were reported for the fiscal year 2001/02. Source of effectiveness data The effectiveness data were derived from a single study. Link between effectiveness and cost data It appears that costing has been conducted retrospectively on the same sample of patients as that used in the effectiveness study. Study sample The sample size was not determined during the planning phase of the study. In addition, power calculations were not conducted retrospectively based on the existing sample. The method used to select the samples was not described, and Page: 1 / 5

2 no patients were reported to have been excluded from the study. Overall, 214 patients were recruited into the study, 107 in each of two groups. The mean age was 9.9 (+/- 4.5) years in the botulinum toxin group and 9.3 (+/- 4.0) years in the control group (no use of botulinum toxin injection). In both groups 61% of the patients were male. Study design The analysis was based on a retrospective single-centred cohort study. The controls were matched to the botulinum cases using the following criteria: age, gender, extent of cerebral palsy (i.e. hemiplegia, diaplegia, tetraplegia) and aetiology (i.e. type of injury causing the cerebral palsy, such as premature birth and asphyxiation). The timeframe of data collected for the botulinum toxin group was not reported. Data for each patient were collected for 12 months (follow-up period). Blinded assessment was not reported. Analysis of effectiveness It was not reported whether the analysis was conducted on an intention to treat basis or for treatment completers only. The primary outcomes were: ambulatory rating and manual disability using the patient categorisation scale of Pharaoh et al. (see 'Other Publication of Related Interest' below for bibliographic details); and tolerance to brace wear at the start and end of the study period, measured using the scale developed by Pierson et al. (see 'Other Publication of Related Interest' below for bibliographic details). The patient groups were comparable at baseline in terms of the demographic characteristics. It was only reported that more patients in the botulinum toxin group used an orthotic at the beginning of the study period than in the control group (64% versus 42%; p<0.001). Effectiveness results The authors reported that there were no statistical differences between the two groups in terms of ambulatory rating, manual disability or brace wear tolerance at the start of the study period and at 12 months. Clinical conclusions The authors concluded that there was no statistically significant difference in clinical outcomes between the two groups. Measure of benefits used in the economic analysis The authors did not use a summary measure of benefit in the economic analysis. As therapeutic equivalence was demonstrated in the effectiveness analysis, the study could be characterised as a cost-minimisation analysis. Direct costs The health care costs included in the analysis were for the botulinum toxin, biochemistry test, blood gas test, blood glucose measure, coagulation test, complete blood count, computerised tomography, cross-matching blood, electrocardiogram, electroencephalogram, hospital inpatient stay per day in ward 3 and 7, microbiological test, occupational therapy session, outpatient visit, physiotherapy session, stool assessment, surgical procedure for muscle lengthening, surgical procedure for tendon lengthening, tendon release or tendon transfer, urinalysis and X-ray. The economic analysis also included orthotic and mobility aid costs, as well as medication costs (e.g. anaesthetic, analgesic, anti-asthmatic, antibiotic, anticoagulant, anti-emetic, anti-spasmodic, hypnotics, laxative, muscle relaxant, nutritional supplement and other drugs). The quantities of resources used were collected from patient records or case notes, while the unit costs were derived primarily from the finance department of the authors' setting and from official sources (drug costs were derived from the Rote Liste 2002). The unit costs were reported for all costs except those of the drugs, orthotics and the mobility Page: 2 / 5

3 aids. The authors reported that all costs were appropriately adjusted for inflation and were reported for the fiscal year 2001/02. Discounting was not relevant as the costs were incurred during less than 2 years. The costs were accounted for over a 1-year period. Statistical analysis of costs The cost estimates were treated deterministically. The authors used a chi-squared test or the Mann-Whitney U-test to estimate differences between the two groups. Indirect Costs The indirect costs were not included in the analysis. Currency Euros (Euro). Sensitivity analysis A multivariate probabilistic sensitivity analysis using Crystal Ball 2000 software (version ; Decisioneering Inc.) was undertaken to test variability in the data. For estimates of resource use, the authors conducted 1,000 interactions in Monte Carlo simulations. The range of the estimates used in Monte Carlo analysis varied randomly between the upper and lower 95% confidence interval. Estimated benefits used in the economic analysis See the 'Effectiveness Results' section. Cost results There was an 85% reduction in the percentage of children needing surgery in the botulinum group compared with the control group, (p<0.0001). In addition, there was a 60% reduction in hospitalisation bed days, (p<0.0001). Eighty-seven per cent of the botulinum toxin group needed multiple orthotics during the 12-month study period compared with 91% of the control group. During the equivalent period, 45% of patients in the botulinum group and 23% in the control group required no amendment to orthotics, while 37% of patients in the botulinum group and 68% in the control group needed a new orthotic. The total costs were reported per patient. The total costs during the first year of treatment were Euro 16,700 per child treated in the botulinum toxin group, while the equivalent cost in the control group was Euro 33,800. The length of hospital stay and the cost of orthotics and mobility aids collectively accounted for 88% of the cost of treating patients in both groups. Synthesis of costs and benefits Not applicable as the study could be characterised as a cost-minimisation analysis. Authors' conclusions The use of botulinum toxin led to a significant reduction in the requirement for surgery and the use of health care resources during the first year following treatment, without any loss of clinical improvement. Page: 3 / 5

4 CRD COMMENTARY - Selection of comparators The use of botulinum toxin seems to have represented a common approach in the authors' setting for the treatment of children with cerebral palsy. The authors chose to compare this drug treatment against no drug. This allowed the active value of the treatment to be evaluated but does not include an active agent as an alternative. You should decide if this represents a widely used technology in your own setting. Validity of estimate of measure of effectiveness The analysis was based on a retrospective cohort study, and effectiveness data were collected from case notes kept on patients at the authors' setting. Although the retrospective nature of the study represents a limitation to the internal validity, the authors reported that the data were screened for accuracy of transcription and completeness, assuming that the quality of the data was good. The study sample was representative of the study population, and the patient groups were shown to be comparable at analysis. However, no power calculations were conducted. Thus, it is not possible to ascertain whether the results obtained were due to the intervention or due to chance. Validity of estimate of measure of benefit As the analysis demonstrated that both treatments were equally effective, only the costs were analysed. A costminimisation analysis was conducted. Validity of estimate of costs The hospital perspective (health care payer) was adopted in the economic analysis. It appears that all the relevant categories of costs have been included in the analysis. The unit costs were reported for most cost categories, thus enhancing the reproducibility of the results to other settings. The quantities of resource use were obtained from case notes on patients and an appropriate statistical analysis was conducted. The costs were derived from official published sources and from the authors' setting. An extensive sensitivity analysis was conducted on the costs and quantities to assess the robustness of the estimates used. All the costs were appropriately inflated and the price year was reported, which will aid any future reflation exercise. Other issues The authors compared their findings with two published studies, generally finding consistency in their conclusions. The issue of generalisability of the results to other settings was directly addressed. Namely, several tools that measure ambulation and manual disability, or the tolerance to brace wear scale, have been accordingly adapted by the authors for the purpose of the retrospective study, and were not used exactly in the way that were originally designed. Therefore, the study findings might have been exposed to recall bias of the clinicians and should be treated with caution. The authors do not appear to have presented their results selectively. The study enrolled children with cerebral palsy and this was reflected in the authors' conclusions. The authors reported several limitations to their study. For example the analysis was based on a single-centre retrospective study and the data were derived from the patients' case notes. Therefore, clinical practice in different settings was not taken into consideration. The study period of 12 months was inadequate to account for long-term effects of the treatment. Finally, the study did not account for indirect societal costs or effects on quality of life. Implications of the study The authors did not make explicit recommendations for changes in policy or practice, or for future research. However, their discussion highlighted areas where more information is needed. Source of funding Supported by Allergan. Page: 4 / 5

5 Powered by TCPDF ( Bibliographic details Ruiz F J, Guest J F, Lehmann A, Davie A M, Guttler K, Schluter O, Dreiss G. Costs and consequences of botulinum toxin type A use: management of children with cerebral palsy in Germany. European Journal of Health Economics 2004; 3(5): Other publications of related interest Pharoah PO, Cooke T, Johnson MA, King R, Mutch L. Epidemiology of cerebral palsy in England and Scotland, Arch Dis Child Fetal Neonatal Ed 1998;79:F21-5. Pierson SH, Katz DI, Tarsy D. Botulinum toxin A in the treatment of spasticity: functional implications and patient selection. Arch Phys Med Rehabil 1996;77: Arroyave Loaiza G, Jarillo Soto EC, Garfias Garnica MG, Ribera Ibarra DB, Uribe Zamarripa JA. Cost-benefit of the pharmacologic treatment of cerebral palsy with spasticity in Mexico. Rev Esp Salud Publica 2000;74: Houltram J, Noble I, Boyd RN, Corry I, Flett P, Graham HK. Botulinum toxin type A in the management of equinus in children with cerebral palsy: an evidence-based economic evaluation. Eur J Neurol 2001;8: Indexing Status Subject indexing assigned by NLM MeSH Adolescent; Botulinum Toxin Type A /administration & dosage /economics /therapeutic use; Cerebral Palsy /drug therapy /economics /surgery; Child; Child, Preschool; Cohort Studies; Comparative Study; Costs and Cost Analysis; Female; Germany; Health Resources /utilization; Humans; Length of Stay; Male; Multivariate Analysis; Neuromuscular Agents /administration & dosage /economics /therapeutic use; Patient Selection; Research Support, Non-U.S. Gov't; Retrospective Studies; Time Factors; Treatment Outcome AccessionNumber Date bibliographic record published 30/04/2006 Date abstract record published 30/04/2006 Page: 5 / 5