Providing an extended use of an otological-specific outcome instrument to derive cost-effectiveness estimates of treatment.

OBJECTIVES: Although quality-adjusted life years (QALYs) are increasingly being used by decision-makers to make comparisons of cost-effectiveness, there are no otological-specific outcome measures that fit within this QALY framework. This study had two main objectives. The first was to provide a means to derive QALYs from a condition-specific otological instrument (Cambridge Otology Quality of Life, COQOL), and the second was to assess the convergent validity, or degree of correlation, between the COQOL and SF-6D, an established QALY instrument. DESIGN: Longitudinal cohort study designed to assess the convergent validity between SF-6D and COQOL and to generate a mapping function to enable SF-6D values to be predicted from the COQOL responses. SETTING: Cambridge University Hospital, UK. PARTICIPANTS: A total of 207 patients attending a routine outpatient general otology clinic. MAIN OUTCOME MEASURES: SF-6D and the COQOL instrument completed at baseline and again 3 months later. RESULTS: Convergent validity was demonstrated with mean SF-6D values decreasing linearly with increasing severity on the COQOL instrument. Overall, the correlation between the COQOL scores and the SF-6D values was moderate and statistically significant (r = 0.490, P = <0.001). A simple mapping model based on an ordinary least squares (OLS) regression function predicted SF-6D values from the COQOL data with a reasonable degree of accuracy. Further validation using the follow-up 3-month data confirmed the prediction power of this mapping model. CONCLUSIONS: This study provides a method for estimating QALYs from condition-specific COQOL data and provides the opportunity for the cost-effectiveness of otological treatment to be measured and placed within the national QALY framework.

Conservative management, surgery and radiosurgery for treatment of vestibular schwannomas: a model-based approach to cost-effectiveness.

OBJECTIVE: To undertake a cost-effectiveness analysis comparing conservative management, surgery and radiosurgery for treating small-to-medium (1-20 mm)-sized vestibular schwannomas. DESIGN: Model-based economic evaluation using individual-level data from a Birmingham-based longitudinal patient database and from published sources. Both a decision tree and state-transition (Markov) model were developed, from an National Health Service (NHS) perspective. Sensitivity analyses were also carried out. SETTING: Secondary care treatment for patients with small-to-medium-sized vestibular schwannomas. PARTICIPANTS: Three hypothetical cohorts of adult patients receiving conservative management, radiosurgery or surgery treatment, aged 58 years as starting age within model. MAIN OUTCOME MEASURES: Cost-effectiveness based on cost per quality-adjusted life year (QALY). RESULTS: Conservative management is the preferred strategy for the treatment of small-to-medium-sized vestibular schwannomas. Conservative management is both cheaper (-£ 722 and -£ 2764) and more effective (0.136 and 0.554 quality-adjusted life years) than both radiosurgery and surgery, respectively. A conservative strategy can therefore be considered as highly cost-effective. This result is sensitive to the assumed quality-of-life parameters in the model. Sensitivity analysis suggests that the probability of a conservative strategy being the most cost-effective approach compared with surgery and radiosurgery at a willingness to pay of £ 20 000/quality-adjusted life year gained is 80% and 55%, respectively. CONCLUSIONS: A conservative approach is the preferred strategy for treatment of small-to-medium vestibular schwannomas. This result is sensitive to quality-of-life values used in the analysis. More research is required to assess the impact of treatment upon patients' health-related quality of life over time.

Eliciting relative preferences for two methods of colorectal cancer screening.

Two methods of mass population screening for colorectal cancer - faecal occult blood testing and sigmoidoscopy - have been the subject of randomized controlled trials in the UK. A national screening programme is currently under consideration and the choice of screening method remains open. To be successful, a programme will require high levels of uptake, and uptake is likely to depend upon subjects' attitudes towards the screening method introduced. Although a preferred screening method has already been identified from a questionnaire survey, we undertook a further interview study (n = 106), with a view to comparing the results of two different approaches to eliciting public preferences. In comparison with the questionnaire study, a higher proportion of interview subjects stated a preference. Interview subjects were generally more favourably disposed towards sigmoidoscopy, excepting those with previous experience. Compared with the questionnaire survey, the interviews provided richer information on the reasons for preferences offered. Individual preferences were evidently subjective and dependant on attitudes towards a variety of method characteristics, such as discomfort, convenience and perceived sophistication. Characteristics such as age and low income, which had predicted preferences in the questionnaire study, predicted preferences in the interview study also. The difference between the results obtained by the different elicitation techniques can be explained in terms of the differential provision of information and sample selection. Conclusions made about public preferences are likely to depend on the technique employed in eliciting them.

Colorectal cancer, screening and survival: the influence of socio-economic deprivation.

OBJECTIVES: To determine the extent to which socio-economic deprivation explains colorectal cancer prevalence, subject participation in screening, and postoperative survival and life expectancy. METHODS: Regression analyses of clinical data from a large randomized controlled trial, augmented by geographical-based indices of deprivation. RESULTS: Deprivation appears to exert no significant impact on colorectal cancer prevalence but is a major factor explaining subject participation in screening. Cancer detection at later stages reduces life expectancy at time of treatment. Females from more-deprived areas have poorer post-treatment life expectancies and survival prospects, independently of their screening behaviour. CONCLUSIONS: Screening increases the chances of having a cancer treated at an earlier stage, and treatment at an earlier stage is associated with longer subsequent life expectancy. However, those from more-deprived areas are less likely to accept an invitation to be screened.