|
Cost-effectiveness of gemcitabine in stage IV non-small cell lung cancer: an estimate using the population health model lung cancer module |
Evans W K |
|
|
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 Gemcitabine (2', 2'-difluorodeoxycytidine) in non-small cell lung cancer (NSCLC).
Economic study type Cost-effectiveness analysis.
Study population Patients with advanced (stage IV) non-small cell lung cancer (NSCLC).
Setting Secondary care and hospital. The economic study was conducted in Ontario, Canada.
Dates to which data relate The effectiveness and resource use data were obtained from studies published in 1990 and 1993. The price year was 1993.
Source of effectiveness data Effectiveness data were derived from a review of previously completed studies.
Modelling A population-based model (i.e. the Population Health Model developed by Statistics Canada) describing the distribution of histologic cell type and stage of disease of NSCLC in Canadians was used to estimate total costs. The model incorporated clinical algorithms reflecting common Canadian approaches to the diagnosis and treatment of lung cancer.
Outcomes assessed in the review The outcome assessed was the survival of advanced NSCLC patients.
Study designs and other criteria for inclusion in the review Phase II and randomised controlled trials were included in the review. No other criteria were reported.
Sources searched to identify primary studies 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 Two primary studies were included in the review. One was a phase 2 trial of the intervention, while the other was a randomised controlled trial comparing best supportive care to chemotherapy.
Methods of combining primary studies Investigation of differences between primary studies Results of the review The average survival increase for patients treated with gemcitabine relative to those treated with supportive care was 0.3959 years. The survival difference (in % of total patients) disappeared just before 39 months after the start of treatment (this result was reported in a graph).
Measure of benefits used in the economic analysis The measure of benefits used in the economic analysis was life years gained.
Direct costs The costs measured were those of hospital, and included operating, overheads, and capital costs. No discounting of costs was reported. Data were obtained mainly from the randomised controlled trial used in the clinical study (data for the work-up resource usage were not available and were, therefore, estimated within the model based on assumptions). Per-diem unit costs were used to value actual data for hospital stay (of both diagnostic work-up and terminal care), and the Ontario Cancer Registry data for 1992 (for diagnostic work-up). It was assumed that the number of days in hospital during terminal care with Gemcitabine was the same as that associated with the standard chemotherapy option used in the clinical trial. Unit costs were taken from the 1993 fee schedule in Ontario, 1993 salary rates at the Ottawa Regional Cancer Centre (for personnel costs), and the 1984 per diem rates from the above-mentioned clinical study (adjusted for the change in those rates between 1984 and 1993). A model was used to calculate total costs. The price year was 1993. Costs incurred by the patient were omitted from the analysis.
Sensitivity analysis A one-way sensitivity analysis was conducted on the following parameters: dose, survival benefit associated with intervention (reduced by 25% and 50%), and the average number of terminal care hospital days for Gemcitabine.
Estimated benefits used in the economic analysis The average number of life years gained with Gemcitabine relative to no chemotherapy (best supportive care) was 0.3959.
Cost results The total cost per patient treated by Gemcitabine (1000 mg/m2) was Can$28,907. The corresponding figure for the supportive care arm was Can$28,617. The first estimate did not include costs associated with side effects.
Synthesis of costs and benefits The additional cost per year of life gained (1993 Canadian dollars) was Can$632. Sensitivity analysis on the parameters of uncertainty showed this ratio to be within a range of -Can$4,257 (intervention was the dominant strategy) to Can$17,390.
Authors' conclusions Gemcitabine appears to be a cost-effective intervention for advanced NSCLC. Moreover, it compares well with accepted strategies from other health care areas. It is likely that an increasing proportion of patients will be offered chemotherapy in the future now that less toxic agents such as Gemcitabine have become available.
CRD COMMENTARY - Selection of comparators The authors justified the choice of comparators in terms of the reduced toxicity observed with Gemcitabine, a new agent used in chemotherapy for treating stage IV patients with non-small cell lung cancer. However, in order for this comparison adequately to address the efficiency question posed, the analysis should refer to those patients for whom the standard combinations of Cyclophosphamide, Doxorubicin, Cisplatin or Vindesine and Cisplatin are not available treatment options (owing, for instance, to functional status). Otherwise, standard chemotherapy should be included as a comparator.
Validity of estimate of measure of benefit The validity of estimate of benefits may be open to doubt because of the lack of control in the effectiveness study. As a result, the authors investigated, by means of sensitivity analysis, how the uncertainty surrounding the estimate of benefit might affect the results of the study.
Validity of estimate of costs No discounting was reported, even though the period of time covered by the analysis was longer than one year. The model assumed that the cost incurred by the intervention in the terminal stage of disease was the same as that recorded for standard chemotherapy. Since this estimate was closely related to the benefits associated with the intervention, further evidence from the clinical side of the study should have been provided.
Other issues The conclusions reached by the authors were justified in terms of the sensitivity analyses. The generalisability of results was implicitly addressed in such analyses. The authors compared the cost effectiveness ratios obtained with those from widely accepted strategies in other health care settings.
Implications of the study Further studies are needed in order to reduce the uncertainty regarding some costs associated with the intervention. Nevertheless, the conclusion that Gemcitabine is a cost-effective strategy for the treatment of stage IV non-small cell lung cancer, for patients without the option of standard chemotherapy treatment, appears to be robust. For those with a good performance status and little weight loss (as in the control group used for the present study), who therefore do have the option of undergoing standard chemotherapy, the study results above do not apply.
Source of funding Supported by a grant provided by Eli Lilly Canada, Inc to Statistics Canada and the Ottawa Regional Cancer Centre.
Bibliographic details Evans W K. Cost-effectiveness of gemcitabine in stage IV non-small cell lung cancer: an estimate using the population health model lung cancer module. Seminars in Oncology 1997; 24(2 Supplement 7): S56-S63 Indexing Status Subject indexing assigned by NLM MeSH Antimetabolites, Antineoplastic /therapeutic use /economics; Canada; Carcinoma, Non-Small-Cell Lung /drug therapy /mortality /economics; Cost-Benefit Analysis; Deoxycytidine /economics /therapeutic use /analogs & Health Care Costs; Health Resources; Humans; Lung Neoplasms /drug therapy /mortality /economics; Models, Economic; Neoplasm Staging; Research Support, Non-U.S. Gov't; Ribonucleotide Reductases /antagonists & Survival Rate; derivatives; inhibitors AccessionNumber 21997000895 Date bibliographic record published 31/12/1998 Date abstract record published 31/12/1998 |
|
|
|