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

Transcription

1 Clinical and economic consequences of volume- or time-dependent intermittent catheterization in patients with spinal cord lesions and neuropathic bladder Polliack T, Bluvshtein V, Philo O, Ronen J, Gelernter I, Luttwak Z P, Hart J, Catz A 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 study compared the use of volume-dependent catheterisation (VDIC) with time-dependent intermittent catheterisation (TDIC) in patients with spinal cord lesions and neuropathic bladder. Type of intervention Treatment. Economic study type Cost-effectiveness analysis. Study population The study population comprised patients with spinal cord lesions and neuropathic bladder requiring intermittent catheterisation by a caregiver. No patients had any additional neurological problems or sores in the sphincteric region. Setting The study setting was secondary care. The economic study was undertaken at the Loewenstein Rehabilitation Hospital, Israel. Dates to which data relate The dates to which the effectiveness and resource use data referred were not reported. The price year was Source of effectiveness data The effectiveness data were derived from a single study. Link between effectiveness and cost data The costing was undertaken prospectively on a sub-group of patients derived from the same study sample as that used in the effectiveness study (9 patients from the control group and 13 patients from the study group). Study sample No sample size appears to have been determined in the planning phase of the study. In addition, no retrospective power calculations were performed. Patients with spinal cord lesions and neuropathic bladder were eligible for inclusion in the study, whereas those who switched to self-catheterisation during the initial days of the study were excluded from the analysis. Twenty-four patients were included in the study, of which 13 were in the study group treated by VDIC and the remaining 11 were in the control group treated by TDIC. The study group comprised 9 men and 4 women, with a mean age of (standard deviation, SD=17.9) years. The control group comprised 6 men and 5 women, with a mean age Page: 1 / 5

2 of 42.7 (SD=20.6) years. Study design The study was a randomised controlled trial (RCT) that was undertaken at the Department of Spinal Rehabilitation, Loewenstein Rehabilitation Hospital, Israel. The authors did not report the method of randomisation. The patients were followed up for 12 to 30 days. The mean follow-up was 19 days in the study group and 20 days in the control group, (p=0.605). No blinded assessment or loss to follow-up was reported. Analysis of effectiveness It appears that the effectiveness data have been analysed on an intention to treat basis. The primary outcomes used were: the decrease in Spinal Cord Independence Measure (SCIMU 1) during the study, which represents the bladder functioning management; the increase in blood creatinine level during the study; and the number of clinical urinary infections. No significant differences were found between the groups in terms of their gender, age or other baseline characteristics. Such characteristics were the as legs American Spinal Injury Association impairment scale Motor Score, which represents the severity of lower body neurological deficit, SCIMU 1 scores and cystometric pressure. Effectiveness results The mean increase in SCIMU values during the study was 6.32 (SD=4.28) in the study group treated with VDIC, and 4.82 (SD=3.25) in the control group treated with TDIC, (p=0.129). The mean increase in blood creatinine levels during the study was (SD=0.072) in the study group treated with VDIC, and (SD=0.102) in the control group treated with TDIC, (p=0.715). No clinical urinary infection was found in any of the patients in the study group treated by VDIC. However, infections were found in 3 patients in the control group treated by TDIC, (p=0.49). Clinical conclusions The authors found no statistically significant differences in outcomes between the two treatment groups. Measure of benefits used in the economic analysis The authors did not derive a summary measure of health benefit. However, as no statistically significant differences in effectiveness were demonstrated, the study could be classified as a cost-minimisation analysis. Direct costs The direct costs included in the analysis were those of the hospital. These included the costs of the equipment used in every catheterisation and the nurse's time devoted to measurement of urine volume and catheterisation. The quantities and the costs were reported and analysed separately. The unit costs were obtained from the administration of the hospital in December Discounting was not required, as the costs were incurred during a short time, and was therefore not performed. The mean costs per patient per day were reported in the study. Statistical analysis of costs The costs were treated stochastically. The comparisons between the groups were performed by t-tests. Statistical Page: 2 / 5

3 significance was set at p<0.05. Indirect Costs The indirect costs were not included. Currency Israel new shekels (ILS). The authors reported that ILS 10 were equivalent to approximately US dollars 2.2. Sensitivity analysis No sensitivity analyses were performed. Estimated benefits used in the economic analysis See the,effectiveness Results- section. Cost results The mean cost per day was ILS (SD=12.35) per patient treated by VDIC and ILS (SD=16.64) per patient treated by TDIC, (p<0.001). Therefore, the total costs were reduced by ILS (46%) per day with VDIC in comparison with TDIC. Synthesis of costs and benefits Not applicable, as the study was a cost-minimisation analysis. Authors' conclusions Treating patients with volume-dependent intermittent catheterisation (VDIC) had economic advantages over timedependent intermittent catheterisation (TDIC). Although the authors could not demonstrate a significant impact of the intermittent catheterisation type on clinical variables, they concluded that VDIC probably had clinical advantages over TDIC. CRD COMMENTARY - Selection of comparators A justification was given for using TDIC as the comparator. It represented current practice in the authors' setting. You should decide if the comparator represents current practice in your own setting. Validity of estimate of measure of effectiveness The analysis was based on an RCT. This was appropriate for the study question, as well-conducted RCTs are considered to be the,gold- standard when comparing health care interventions. The study sample appears to have been representative of the study population. The authors found no statistically significant differences between the two patient groups in terms of their age, gender and prognostic features. However, the authors acknowledged that the study sample was very small and, therefore, the study would appear to be underpowered to detect any differences in baseline characteristics or clinical outcomes between the two groups. The authors also acknowledged that the follow-up period might have been too short for the study question. In addition, blinding of the outcome assessment and randomisation concealment were not reported. These factors may introduce potential bias. Validity of estimate of measure of benefit The authors did not derive a summary measure of health benefit. Page: 3 / 5

4 Validity of estimate of costs All the categories of cost relevant to the health care provider perspective were included in the analysis. However, some relevant costs were excluded from the analysis, such as the costs of urinary tract infections or other adverse events prevented or caused by catheterisation. Such omissions would appear to be biased against the study treatment (i.e. VDIC) as this treatment was associated with lower infections. The costs and the quantities were reported separately, thus enhancing the reproducibility of the study in other settings. The costs were derived from the administration of the authors' hospital. Appropriate statistical analyses of the mean costs between the two treatment groups were performed and, although the study was based on a very small patient sample, statistically significant differences in costs were found by the authors. The authors reported costs in Israeli new shekels (ILS), but provided relevant exchange rates to convert their cost estimates into US dollars. Since the costs were incurred during a short timeframe, discounting was unnecessary and was therefore not performed. The price year was reported, which will aid any possible inflation exercises. Other issues The authors reported that previous studies had also documented the advantages of VDIC. However, according to the authors, these studies were based on a limited number of patients with spinal cord lesions. The issue of generalisability to other settings was not addressed. The authors do not appear to have presented their results selectively, and their conclusions reflected the scope of the analysis. The authors reported a number of further limitations to their study. First, their study sample was possibly too small and/or follow-up was too short to detect any significant differences in clinical outcomes. Second, the exclusion of patients who switched to self-intermittent catheterisation earlier could have biased their results, as some of these patients might have started self-catheterisation earlier because they required less catheterisation even with TDIC, hence increasing the average number of catheterisations in the control group. Implications of the study The authors reported that, despite the study's limitations, the findings of their study demonstrated the advantages of VDIC over TDIC. Source of funding Supported by the Israel Ministry of Defence. Bibliographic details Polliack T, Bluvshtein V, Philo O, Ronen J, Gelernter I, Luttwak Z P, Hart J, Catz A. Clinical and economic consequences of volume- or time-dependent intermittent catheterization in patients with spinal cord lesions and neuropathic bladder. Spinal Cord 2005; 43(10): PubMedID DOI /sj.sc Other publications of related interest Anton HA, Chambers K, Clifton J, et al. Clinical utility of a portable ultrasound device in intermittent catheterisation. Arch Phys Med Rehab 1998;79: De Ridder D, Van Poppel H, Baert L, et al. From time dependent intermittent self-catheterisation to volume dependent self-catheterisation in multiple sclerosis using the PCI 5000 Bladder manager. Spinal Cord 1997;35: Indexing Status Page: 4 / 5

5 Powered by TCPDF ( Subject indexing assigned by NLM MeSH Adult; Cost-Benefit Analysis; Female; Humans; Male; Spinal Cord Injuries /economics /therapy; Time Factors; Urinary Bladder, Neurogenic /economics /therapy; Urinary Catheterization /adverse effects /economics /methods; Urinary Tract Infections /etiology AccessionNumber Date bibliographic record published 30/06/2006 Date abstract record published 30/06/2006 Page: 5 / 5