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Evaluating the economic consequences of early antidepressant treatment discontinuation: a comparison between controlled-release and immediate-release paroxetine |
Sheehan D V, Eaddy M, Sarnes M, Vishalpura T, Regan T |
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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 Paroxetine controlled release (CR) was compared with paroxetine immediate release (IR) in a naturalistic setting.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients aged at least 18 years old who had a pharmacy claim for paroxetine CR or paroxetine IR on or after 1st April 2002. The patients were required to have been newly started on selective serotonin reuptake inhibitor (SSRI) therapy and, therefore, were required to have 6 months of enrolment data before their index date without evidence of antidepressant therapy. The patients were also required to have a diagnosis of depression, panic disorder, or social anxiety disorder. Patients were excluded if they had a psychosis-related diagnosis of schizophrenia or bipolar disorder, or had received antipsychotic medication in the 6 months before or 6 months after being identified for inclusion in the study. The target population appears to have been the same as the study population.
Setting The setting was reported to be a naturalistic setting, which appears to equate to the community in the USA. The economic study was carried out in the USA.
Dates to which data relate The effectiveness data were collected from the Pharmetrics Integrated Outcomes Database (Watertown, MA). The data were collected for patients receiving paroxetine CR or IR on or after 1st April 2002. The resource use data would appear to refer to the same dates. The prices appear to relate to 2002 onwards.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data Although not explicitly stated, the costing appears to have been undertaken retrospectively on the same patient sample as that used in the effectiveness study.
Study sample The sample size was not determined in the planning stages of the study. Patients were selected for inclusion in the study if they had a pharmacy claim for paroxetine CR or IR on or after 1st April 2002. The authors did not justify their choice of the patient sample with respect to the characteristics of the treatment under investigation. The percentage of patients excluded was not reported. A total of 3,825 patients were included in the analysis.
Study design The study was a retrospective cohort analysis that appears to have included patients from a number of centres. The timeframe was 180 days.
Analysis of effectiveness The primary health outcome was time to discontinuation. It was unclear whether participants were excluded if they had incomplete data. The groups were comparable at analysis.
Effectiveness results At 90 days, 62% of paroxetine CR patients remained on therapy compared with 56% of paroxetine IR patients.
At 180 days, 51% of paroxetine CR patients remained on therapy compared with 42% of paroxetine IR patients.
Clinical conclusions The clinical conclusions were that, over a 180-day period, fewer patients on paroxetine CR discontinued compared with paroxetine IR.
Measure of benefits used in the economic analysis The authors did not derive a summary measure of benefit. In effect, a cost-consequences analysis was performed.
Direct costs The costs of the health care provider were included in the analysis. These included the total amounts charged for physician visits, inpatient hospitalisation, outpatient hospital care, emergency department visits, antidepressant prescription medications, and other services. The source of the resource use data appears to have been charge data from the Pharmetrics Integrated Outcomes Database. The quantities and the costs were not reported separately. Discounting was not relevant since the costing was undertaken over a 6-month period. The prices appear to relate to 2002 onwards.
Statistical analysis of costs The data were deterministic.
Indirect Costs The indirect costs were not reported
Sensitivity analysis A sensitivity analysis was not carried out.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results Paroxetine CR patients incurred approximately $119 less per month than paroxetine IR patients, (p=0.054), when unadjusted total monthly medical costs were evaluated.
Monthly antidepressant pharmacy charges for paroxetine CR averaged $10 more than paroxetine IR ($77.35 versus $67.34; p<0.05).
There was a $107 saving for the paroxetine CR cohort when unadjusted monthly medical and antidepressant pharmacy charges were combined, (not statistically significant).
Further details of the costs were not provided.
Synthesis of costs and benefits The costs and benefits were not combined.
Authors' conclusions Patients treated with paroxetine controlled release (CR) remained on the therapy longer than patients on paroxetine immediate release (IR). The longer length of therapy needed for paroxetine CR was associated with lower, total monthly medical costs.
CRD COMMENTARY - Selection of comparators The comparator was justified on the grounds that it was current practice. You should decide if this is current practice in your own setting.
Validity of estimate of measure of effectiveness The analysis was based on a retrospective cohort design. A randomised controlled trial would have been more appropriate. The study sample was representative of the study population. The patients were shown to have been comparable at analysis.
Validity of estimate of measure of benefit The authors did not derive a summary measure of health benefit. The study was, in effect, a cost-consequences analysis.
Validity of estimate of costs All the categories of cost relevant to the perspective adopted were included in the analysis. The costs and the quantities were not reported separately. No statistical analysis of the quantities or prices was performed.
Other issues The authors made appropriate comparisons of their findings with those from other studies. The issue of generalisability to other settings was not fully addressed. The authors appear to have presented their results selectively. The authors reported a number of further limitations to their study. First, the patients were not randomised to a treatment, thus differences in the outcomes could be due to factors that could not be controlled or assessed. Second, since the study wan a retrospective analysis of data from a database, the exact reason for treatment discontinuation could not be ascertained. Finally, resource utilisation was used as an effectiveness proxy, thus the study did not directly assess the effectiveness of the agents in reducing the signs and symptoms of depression or anxiety. The authors noted that it is plausible that the effect of this study cannot be extrapolated beyond the 180-day timeframe, and that there may be concern about an assessment of charges for patients with differential follow-up times.
Implications of the study The authors made no specific recommendations for changes in policy, or for future research.
Source of funding Funded by GlaxoSmithKline.
Bibliographic details Sheehan D V, Eaddy M, Sarnes M, Vishalpura T, Regan T. Evaluating the economic consequences of early antidepressant treatment discontinuation: a comparison between controlled-release and immediate-release paroxetine. Journal of Clinical Psychopharmacology 2004; 24(5): 544-548 Indexing Status Subject indexing assigned by NLM MeSH Adult; Antidepressive Agents, Second-Generation /adverse effects /economics /therapeutic use; Cost Savings /statistics & Delayed-Action Preparations /economics; Depressive Disorder /drug therapy /economics; Drug Costs /standards; Female; Health Expenditures /statistics & Hospitalization /economics; Humans; Male; Managed Care Programs /economics; Matched-Pair Analysis; Middle Aged; Panic Disorder /drug therapy /economics; Patient Dropouts /statistics & Phobic Disorders /drug therapy /economics; Retrospective Studies; Serotonin Uptake Inhibitors /adverse effects /economics /therapeutic use; Survival Analysis; Treatment Outcome; United States; numerical data; numerical data; numerical data AccessionNumber 22004001320 Date bibliographic record published 30/09/2005 Date abstract record published 30/09/2005 |
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