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Genetic nurse counsellors can be an acceptable and cost-effective alternative to clinical geneticists for breast cancer risk genetic counselling: evidence from two parallel randomised controlled equivalence trials |
Torrance N, Mollison J, Wordsworth S, Gray J, Miedzybrodzka Z, Haites N, Grant A, Campbell M, Watson M S, Clarke A, Wilson B |
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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 the use of genetic nurse counsellors as an alternative to clinical geneticists for counselling on genetic risk of breast cancer. Genetic counselling services are aimed at identifying individuals at significantly increased genetic risk of cancer and to counsel them about appropriate risk management. The process includes family history taking, pedigree construction, confirmation of cancer diagnoses in affected relatives, risk assessment, genetic counselling and advice on preventive strategies.
Type of intervention Screening and counselling.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients newly referred for genetic counselling because of concern about a family history of breast cancer. To be included, the patients had to be aged at least 18 years and be literate in English. Patients who had previously attended the genetics clinic, those affected by breast cancer before, and those with a family member identified as having a BRCA1 or BRCA2 mutation were excluded from the study.
Setting The setting was primary care. The economic study was carried out in the Grampian region (Aberdeen) and Wales (Cardiff), UK.
Dates to which data relate The dates during which patients were recruited into the study were not reported. The price year was reported to be 2006.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data The resource use data were collected prospectively from the same patient sample as that used in the effectiveness study.
Study sample A sample size able to detect equivalence (two-sided) in the primary outcome of anxiety, as measured by the Spielberger State-Trait Anxiety Inventory (STAI) with power 80% at the 5% significance level, was calculated. The equivalence limit for the 95% confidence interval (CI) of any observed difference was set at an overlap of +/- 4 units. The calculation assumed a standard deviation of 12 units for the STAI and accounted for the 2:1 allocation ratio to intervention:control. Eligible patients were identified from letters referring them for genetic counselling services at the study centres. The authors stated that a high proportion of eligible patients were recruited, suggesting that the study sample was representative of the target population.
In the Grampian region, 342 (66%) out of 517 referred patients consented to be included in the study and were randomised to receive counselling from genetic nurses (227) or standard physician-based care (115). Of the 175 patients not randomised, 48 refused to take part, 28 did not fulfil the inclusion criteria and 99 did not respond to recruitment. Of those randomised, 289 (84%) returned a baseline questionnaire and attended the clinic (193 intervention, 96 control).
In Wales, 373 (80%) out of 464 referred patients consented to be included in the study and were randomised to receive counselling from genetic nurses (247) or standard physician-based care (123). Of the 91 patients not randomised, 26 refused to take part, 6 did not fulfil the inclusion criteria and 59 did not respond to recruitment. Of those randomised, 297 (80%) returned a baseline questionnaire and attended the clinic (197 intervention, 100 control).
Study design The study was a pragmatic, randomised, controlled, equivalence trial. The study had two centres, one in Aberdeen and one in Cardiff. The random allocation schedule sequence was computer-generated. Members of the same family were allocated to the same trial group to avoid contamination. Follow-up was for 6 months after the counselling episode. The counselling episode consisted of the time from the initial appointment scheduling to discharge, or until further management arrangements were made. Of the 342 patients randomised in the Grampian region, 237 completed the trial. Of the 373 patients randomised in Wales, 223 completed the trial. The authors did not report any blinding.
Analysis of effectiveness The analysis of effectiveness was conducted on an intention to treat basis for those patients who returned a baseline questionnaire and attended clinic. A per protocol analysis was also performed. The primary health outcome used in the analysis was anxiety, as measured by STAI. A strict equivalence limit for an observed difference in STAI was set before the trial at +/- 4 units. During the trial, but before data were released for analysis, a likely equivalence limit of +/- 10 units was set. In the Grampian region, the actual estimated lifetime risk of breast cancer was found to be higher in the intervention group than in the control group. The converse was true in Wales.
Effectiveness results Immediately after the counselling episode, the observed difference in STAI between intervention and control was 0.8 (95% CI: -2.1 to 3.7) in the Grampian region and -1.5 (95% CI: -4.5 to 1.5) in Wales.
At 6 months from baseline, the difference was 2.9 (95% CI: -0.2 to 5.9) in the Grampian region and 0.6 (95% CI: -2.9 to 4.1) in Wales. Both met the criteria for "likely equivalence".
Clinical conclusions The authors concluded that nurse counsellors can provide equivalent care to that provided by clinical geneticists for the initial episode of genetic counselling.
Measure of benefits used in the economic analysis No summary measure of health benefits was derived. In effect, a cost-consequences analysis was performed.
Direct costs The study included the direct costs to the health service and to the patients. Data on the quantities and unit costs per counselling appointment were reported separately. The resource use items measured included staff consumables, use of rooms and equipment, outpatient appointments and staff preparation time for appointments. An equivalent annual cost was calculated for equipment items using a discount rate of 6%. The unit costs were based on local data where available, and otherwise on national rates. Data on patient time and travel costs were collected for use in the sensitivity analysis. The price year was reported to be 2006. Discounting was not relevant as the length of follow-up was less than one year.
Statistical analysis of costs The costs were treated stochastically and the mean and standard deviation of the cost-difference between the two arms were presented. The authors did not specify the tests used in the analysis of the costs.
Indirect Costs The indirect costs were not included in the analysis. This is not consistent with the authors' stated societal perspective.
Sensitivity analysis A sensitivity analysis was used to test the robustness of the findings to the inclusion of patient time and travel costs. Several other one-way sensitivity analyses were conducted to test the robustness of the findings to the grade of staff employed, the level of supervision of the nurse counsellor, the length of the counselling appointments, the choice of discount rate and the assumed lifespan of equipment.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results In the Grampian region, the mean cost per patient was 136.55 for patients randomised to nurse counsellors and 148.30 for patients randomised to standard care. The mean difference was -11.54 (95% CI: -25.43 to 1.94).
In Wales, the mean cost per patient was 140.10 for patients randomised to nurse counsellors and 127.60 for patients randomised to standard care. The mean difference was 12.50, and was the same for all patients as they each received only one counselling appointment.
Synthesis of costs and benefits Authors' conclusions The results of the study added to the evidence supporting the effectiveness, and possible cost-effectiveness, of using nurse counsellors to provide genetic counselling.
CRD COMMENTARY - Selection of comparators The comparator was selected to reflect historical current practice in the study setting. The intervention reflected an undergoing change in practice in some centres which the authors felt should be subject to evaluation. You must decide whether the genetic counselling services provided in the UK are representative of services provided in your own setting.
Validity of estimate of measure of effectiveness The analysis of effectiveness was based on a pragmatic randomised controlled trial. The method of randomisation, length of stay and follow-up were all reported. This study design was suitable for the study question. Power calculations were used to ensure an adequate sample size, and the sample recruited appears to have been representative of the target population. The authors reported baseline differences in the actual elevated lifetime risk of breast cancer between the intervention and control groups in each centre. However, the analysis does not appear to have been adjusted for baseline differences.
Validity of estimate of measure of benefit No summary measure of health benefit was calculated and, in effect, a cost-consequences analysis was performed. The reader is referred to the comments in the 'Validity of estimate of measure of effectiveness' field (above).
Validity of estimate of costs Although the authors stated that a societal perspective was adopted, they did not include any indirect costs. The quantity of counselling appointments was reported separately from the unit costs. The resource use quantities were derived from a single trial, while the unit costs were based on local or national estimates. Resource use quantities, and hence total costs, were treated stochastically in the Grampian region. However, in Wales, each patient received only one appointment to which a deterministic unit cost was assigned. The price year was reported.
Other issues The authors made appropriate comparisons of their findings with those from other studies. The authors commented that, despite the population differences between the two study centres (Grampian region and Wales), the observed effectiveness was similar. The authors do not appear to have presented their results selectively. The primary focus of this study was not the economic evaluation, so the authors focused little on the economics in the discussion, thereby limiting its value as an economic evaluation.
Implications of the study The authors recommend that the results of this study be taken into consideration by decision-makers planning and evaluating genetic health services.
Source of funding Funded by the NHS Health Technology Assessment programme.
Bibliographic details Torrance N, Mollison J, Wordsworth S, Gray J, Miedzybrodzka Z, Haites N, Grant A, Campbell M, Watson M S, Clarke A, Wilson B. Genetic nurse counsellors can be an acceptable and cost-effective alternative to clinical geneticists for breast cancer risk genetic counselling: evidence from two parallel randomised controlled equivalence trials. British Journal of Cancer 2006; 95(4): 435-444 Other publications of related interest Because readers are likely to encounter and assess individual publications, NHS EED abstracts reflect the original publication as it is written, as a stand-alone paper. Where NHS EED abstractors are able to identify positively that a publication is significantly linked to or informed by other publications, these will be referenced in the text of the abstract and their bibliographic details recorded here for information
Indexing Status Subject indexing assigned by NLM MeSH Adolescent; Adult; Anxiety; Breast Neoplasms /genetics /psychology; Cost-Benefit Analysis; Female; Genetic Counseling /economics /methods; Health Status; Humans; Nurses; Patient Education as Topic; Patient Satisfaction; Risk AccessionNumber 22006001753 Date bibliographic record published 28/02/2007 Date abstract record published 28/02/2007 |
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