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Cost effectiveness of fluvoxamine in the treatment of recurrent depression in France |
Nuijten M, Hadjadjeba L, Evans C, van den Berg 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 Treatment with selective serotonin reuptake inhibitors (SSRIs) fluvoxamine for patients with depressive disorders.
Economic study type Cost-effectiveness analysis.
Study population Patients with depressive episodes.
Setting Hospital. The economic study was carried out in France.
Dates to which data relate The data used in the effectiveness analysis were based on studies from 1973-1996. The price year was 1996. The estimate of resource use was based on the opinion of an expert panel; it was not reported to which time frame the estimate corresponded.
Source of effectiveness data The effectiveness data were derived from a review of completed studies and a Delphi panel's opinion.
Modelling A Markov model was constructed in order to estimate the costs and benefits associated with each treatment modality (SSRI fluvoxamine or TCA) for 18-months. This duration corresponds to the duration of treatment of a depressive episode.
Outcomes assessed in the review The outcomes assessed in the review were: response rates to treatment, response rate to increased dosage, relapse and recurrence for fluvoxamine and TCA respectively.
Study designs and other criteria for inclusion in the review A large multicentre, prospective, randomized, double-blind, parallel group clinical trial comparing fluvoxamine with placebo; 2 randomized double-blind clinical trials of SSRIs; a large, multicentre long term open study; a small trial (n=55) of open therapy followed by a period of randomization and double-blind therapy; and two multicentre randomized trials.
Sources searched to identify primary studies Primary studies were identified through a search of MEDLINE, in house sources and references provided by experts in the field.
Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included Nine studies were included in the review.
Methods of combining primary studies The relapse rate for fluvoxamine was based on the average rate of relapse found in 2 randomized controlled trials (RCTs), and the relapse rate for TCAs was based on the median rate in 4 trials. The remaining probabilities were obtained from different studies.
Investigation of differences between primary studies Results of the review The results of the review were as follows:
The probability per cycle of the response rate to fluvoxamine was 0.60, and the probability of the response rate to increased fluvoxamine dosage was 0.30.
The probability per cycle of the response rate to TCA was 0.60, and the probability of the response rate to increased TCA dosage was 0.30.
The probability of relapse for fluvoxamine patients was 0.011, and the probability of recurrence for fluvoxamine patients was 0.017.
The probability of relapse for TCA patients was 0.066, and the probability of recurrence for TCA patients was 0.013.
The probability of recurrence for patients off treatment was 0.063.
Methods used to derive estimates of effectiveness An expert panel of 3 GPs and 3 psychiatrists was used to derive estimates of effectiveness.
Estimates of effectiveness and key assumptions The expert panel estimated the transitional probabilities that could not be obtained from other sources. The expert panel estimated that the probabilities of response to first cycle of hospitalisation was 0.75, to second cycle of hospitalisation, 0.75, and to third cycle of hospitalisation, 0.50.
Measure of benefits used in the economic analysis The benefit measure was time without depression expressed as percentage of the total treatment period.
Direct costs Discounting was not applied due to the short time horizon of the study. Quantities were not reported separately from the costs. However, cost items were reported separately. The costs of medication, GP consultation and hospitalisation were included in the analysis. The expert panel provided estimates for the resource use. Unit costs were derived from National Statistics and literature published in 1994 and 1996. The authors adopted a societal perspective. The analysis was also carried out from the perspective of a health insurer. 1996 price data were used. Cost data were inflated to 1996 prices.
Indirect Costs Discounting was not applied due to the short time horizon of the study. Quantities were not reported separately from the costs. However, cost items were reported separately. Work-days lost during treatment were considered. The value of work days lost was calculated by dividing gross domestic product (GDP) per capita (1996) by the actual number of working days. Figures for working days lost were derived from the published literature. 1996 price data were used.
Sensitivity analysis A series of one-way sensitivity analyses was performed on the main variables such as the dosage of fluvoxamine, relapse rate of TCA, and the recurrence rate of fluvoxamine. A scenario analysis was also carried out to evaluate the impact of a maintenance therapy with a TCA after a successful continuation treatment on the study outcomes.
Estimated benefits used in the economic analysis Time without depression for the fluvoxamine therapy was 79% of the total treatment period as opposed to 71% for the TCA therapy.
Cost results The total cost (direct and indirect) of TCA from the societal perspective was Ffr52,257, which was higher than that of fluvoxamine (Ffr40,232). From the perspective of a health insurer, the total cost of treatment using fluvoxamine was Ffr21,911, which consists of medication costs (Ffr2,269), consultation costs (Ffr1,007) and hospitalisation costs (Ffr18,635). In contrast, the total cost of treatment using TCA was Ffr24,512. TCA medication costs were Ffr1,183, TCA consultation costs were Ffr1,215, and TCA hospitalisation costs were Ffr22,114.
Synthesis of costs and benefits Costs and benefits were not combined as the use of fluvoxamine was the dominant strategy. The sensitivity analysis established the robustness of the results.
Authors' conclusions On the basis of the assumptions used in the model, the use of fluvoxamine as maintenance therapy is clinically and economically justified in patients with depressive disorders.
CRD COMMENTARY - Selection of comparators The rationale for the choice of the comparator is clear. TCAs, at the time of the study, were used in the treatment of patients with depressive episodes in France. You, as a database user, should consider whether this is a widely used health technology in your own setting.
Validity of estimate of measure of benefit The internal validity of the estimate of benefit should be evaluated taking into account the following points:
(1) It is not clear how comprehensive the review of the literature was, although probabilities were derived mainly from studies using randomized designs;
(2) Expert opinion was used in determining probabilities, which could not be obtained from the literature.
Validity of estimate of costs Quantities were not reported separately from the costs. Adequate details of methods of cost estimation were given. The resource use estimates were based on expert opinion. Cost results referred to a French setting and may not be generalisable to other countries.
Other issues As acknowledged by the authors, the results from the study should be treated with some caution (with respect to limitations of the modelling studies). The issue of generalisability was not fully addressed, although, appropriate comparisons were made with other studies.
Implications of the study The results of this study confirm that the use of maintenance therapy with fluvoxamine in the treatment of depressive disorders is justified. Three previous modelling exercises, which used different assumptions, time periods and data sources, have also reached similar conclusions to those found in this study: the higher antidepressant costs of SSRIs are offset by savings due to a reduction in hospitalisation.
Source of funding Grant from Solvay Duphar BV.
Bibliographic details Nuijten M, Hadjadjeba L, Evans C, van den Berg J. Cost effectiveness of fluvoxamine in the treatment of recurrent depression in France. PharmacoEconomics 1998; 14(4): 433-445 Indexing Status Subject indexing assigned by NLM MeSH Antidepressive Agents, Second-Generation /economics /therapeutic use; Cost-Benefit Analysis; Depressive Disorder /drug therapy /economics; Fluvoxamine /economics /therapeutic use; France; Humans; Markov Chains; Serotonin Uptake Inhibitors /economics /therapeutic use; Treatment Outcome AccessionNumber 21999008165 Date bibliographic record published 31/07/2000 Date abstract record published 31/07/2000 |
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