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Economic evaluation of a geriatric day hospital: cost-benefit analysis based on functional autonomy changes |
Tousignant M, Hebert R, Desrosiers J, Hollander M J |
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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 examined a geriatric day hospital (GDH) aimed at providing institutional care to elderly people. The programme, which was based on a multidisciplinary approach, delivered a wide spectrum of care. The care was provided by physicians, nurses, occupational therapists, physiotherapists, speech therapists, neuropsychologists, gerontopsychiatrists, dieticians and social workers.
Study population The study population comprised elderly people affected by functional decline and who were eligible for GDH programmes.
Setting The setting was a geriatric institution. The economic study was carried out in Canada.
Dates to which data relate The effectiveness and resource use data were gathered from April 1998 and March 1999 for the intervention group and from a study published in 1996 for the control group. The price year was 1998.
Source of effectiveness data The effectiveness evidence was derived from a single study.
Link between effectiveness and cost data The costing was carried out prospectively on the same sample of patients as that used in the effectiveness study.
Study sample Power calculations were not reported. Of the 171 patients initially identified in the GDH programme, 20 refused to participate. Thus, the final study sample included in the intervention group comprised 151 patients (53 men and 98 women) with a mean age of 76.8 (+/- 6.8) years. The control patients were identified from a published longitudinal study (Hebert et al., see Other Publications of Related Interest) and were matched with patients in the intervention group. There were 53 men and 98 women in the comparison group, and the mean age was 79.3 (+/- 4.2) years.
Study design The study was based on a quasi-experimental design with a historical cohort as the comparison group. The study was carried out at the Sherbrook Geriatric University Institute in the Province of Quebec, Canada. The patients in the intervention group remained in the GDH programme for an average of 15.6 (+/- 7.7) weeks. The control patients were followed for one year. Follow-up data were presumably available for all patients.
Analysis of effectiveness All of the patients included in the initial study sample were accounted in the effectiveness analysis. The main outcome measure used was the change in functional autonomy. This was estimated using the Functional Autonomy Measurement System (SMAF), which was administered by a trained health professional. The tool consisted of 29 functions scored from 0 to 3, with a total potential score of 87. Negative values suggested improvements in functional autonomy. The mean time to institutionalisation or death in the control group was also determined to define the summary benefit measure. In terms of the baseline comparability of the two study groups, despite the initial matching process, the control patients were significantly older and less disabled than the intervention patients.
Effectiveness results The SMAF score changed from 17.9 (+/- 10.5) to 14.8 (+/- 10.6) in the intervention group (difference -3.1 +/- 5.4), and from 15.9 (+/- 6.9) to 18.8 (+/- 12.1) in the control group (difference 2.9 +/- 9.5).
The mean time to institutionalisation or death in the control group was 51 months (1,551 days).
Clinical conclusions The effectiveness analysis showed that, compared with standard care, the GDH programme was effective in improving functional autonomy in elderly people.
Measure of benefits used in the economic analysis The summary benefit measure in the cost-benefit framework was the economic improvement in functional autonomy changes. This was derived from the effectiveness analysis and was then converted into monetary values using a published formula. In particular, the specific relationships between disability score (SMAF), nursing time and cost, in relation to different living settings, were determined using a regression equation. The difference in benefits associated with functional autonomy at admission and at discharge was estimated. Moreover, the difference in benefits associated with change in functional autonomy was adjusted to account for the natural decline in functional autonomy during the time interval of the GDH programme. The natural decline over time measured with the SMAF in the comparison group was used to adjust the difference in benefits from admission to discharge in the GDH programme. A survival analysis of the control group to institutionalisation or death was also used to estimate the time over which the benefit has to be spread. These calculations were described in more detail in the paper.
Direct costs Discounting was not relevant since the costs were incurred during less than 2 years. Both medical and non-medical direct costs were considered in the analysis. However, only GDH-related costs were considered and these were estimated as the incremental costs over usual care. The unit costs were presented separately from the quantities of resources used. The economic evaluation comprised general costs which were borne by the elderly. For example, the costs of the GDH unit, support services, and administrative support, specialised costs (i.e. specialised health professional caring for specific patients) and indirect costs (i.e. transportation and lunch). The costs of the GDH unit covered administration, staff, services related to patient care, and furniture.
The cost/resource boundary of the patient and service provider was adopted. Resource use was estimated using patient-level data derived from the sample of patients included in the clinical study. Economic data were obtained from multiple sources, including the Monthly Financial report and the Annual Financial report of the study institution, the Cost Allocation by Program report, and the Daily Statistics report. The cost calculations were described extensively in the paper. All of the costs were presented in 1998 values.
Statistical analysis of costs The costs were treated deterministically.
Indirect Costs The indirect costs were not considered in the economic evaluation.
Sensitivity analysis Sensitivity analyses were not performed.
Estimated benefits used in the economic analysis The total economic benefits for the 151 patients were Can$2,183,077. The mean economic benefit of the GDH programme per patients was Can$14,457 (+/- 18,978). The median economic benefit per patient was Can$7,775 (semi-interquartile range: 12,659).
Cost results The total costs for the 151 patients were Can$1,021,681.
The mean cost of the GDH programme per patient was Can$6,766 (+/- 3,584).
The median cost per patient was Can$6,090 (semi-interquartile range: 6,215).
Synthesis of costs and benefits The costs and benefits were combined by calculating the difference between the costs and benefits and by estimating the cost-to-benefit ratio. The difference between the costs and benefits was Can$1,161,395. The cost-to-benefit ratio showed that for Can$1 invested in the GDH programme, the benefit for society was Can$2.14 (95% confidence interval: 1.72 - 2.56).
Authors' conclusions The geriatric day hospital (GDH) programme was a cost-effective intervention for the management of elderly people affected by functional decline in Canada.
CRD COMMENTARY - Selection of comparators The selection of the comparators appears to have been appropriate as it reflected standard patterns of care in the study institution. However, there was no information on the characteristics of usual care. You should decide whether this is a valid comparator in your own setting.
Validity of estimate of measure of effectiveness The authors selected a quasi-experimental design because it was unethical to choose a fully experimental design. Therefore, the design of the study was appropriate for the study question. The two groups considered in the study were not evaluated simultaneously and despite the efforts made to create two comparable samples, statistically significant differences existed between the groups. Further, the length of follow-up was different in the two groups. However, the control group was not used for a direct comparison, but only to estimate the natural decline of functional autonomy (longitudinal study). Thus, although the lack of comparability between groups remains an issue, it is less important than in direct comparisons. Power calculations were not performed and there was no evidence that the sample size was appropriate. The evidence came from a single centre and it was unclear whether the study sample was representative of the patient population. These issues tend to limit the internal validity of the analysis.
Validity of estimate of measure of benefit The summary benefit measure reflected the cost-benefit approach used in the economic analysis. The authors converted the change in functional autonomy into monetary values using a benefit estimation method that had been published.
Validity of estimate of costs The authors stated that a societal perspective was adopted. As such, it appears that all the relevant categories of costs have been included. The indirect costs, such as productivity losses, were not considered because of the advanced age of the study population. A detailed breakdown of the cost items was reported and information on the data sources, resource use, unit costs and cost calculations was extensive. This enhances the possibility of replicating the study. Similarly, the price year was reported, which aids reflation exercises in other settings. The costs of usual care were not estimated and only the incremental costs of delivering the GDH programme were calculated. The costs were treated deterministically and all of the economic data were specific to the study setting. Sensitivity analyses were not performed.
Other issues The authors stated that their study was the first one to evaluate the change in functional outcomes for elderly people using a cost-benefit approach for GDH. Therefore, it was not possible to compare their findings with those from other studies. The authors highlighted the robustness of both the cost and effectiveness estimates, which enhanced the validity of the study conclusions. The authors did not address the issue of the generalisability of the study results to other settings and they did not carry out any sensitivity analysis. This reduced the external validity of the analysis.
Implications of the study The study results supported the use of GDH programmes for the improvement of functional autonomy in elderly people. The authors stated that further studies should be carried out to corroborate the findings of the current analysis.
Source of funding Funded by the National Cost-effectiveness Study of Home Care-Health Canada.
Bibliographic details Tousignant M, Hebert R, Desrosiers J, Hollander M J. Economic evaluation of a geriatric day hospital: cost-benefit analysis based on functional autonomy changes. Age and Ageing 2003; 32(1): 53-59 Other publications of related interest Hebert R, Bravo G, Korner-Bitensky N, et al. Predictive validity of a postal questionnaire for screening community-dwelling elderly individuals at risk of functional decline. Age and Ageing 1996;25:159-67.
Hebert R, Dubuc N, Boteau M, et al. Resources and costs associated with disabilities of elderly people living at home and institutions. Canadian Journal of Aging 2001;20:1-21.
Indexing Status Subject indexing assigned by NLM MeSH Activities of Daily Living /classification; Aged; Aged, 80 and over; Canada; Chronic Disease /economics /rehabilitation; Cohort Studies; Cost-Benefit Analysis; Day Care, Medical /economics; Female; Geriatrics /economics; Hospital Costs /statistics & Hospitals, Special /economics; Humans; Male; National Health Programs /economics; numerical data AccessionNumber 22003000399 Date bibliographic record published 31/08/2005 Date abstract record published 31/08/2005 |
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