Economic evaluation: Difference between revisions
(do not need to be calculated) |
No edit summary |
||
Line 14: | Line 14: | ||
== Answer == | == Answer == | ||
A general approach to answer the question is based on the concept of incremental | A general approach to answer the question is based on the concept of incremental cost-effectiveness. For example, if there are only two vaccines to be compared, the more effective (and more expensive vaccine) is said to be more cost-effective if the incremental cost effectiveness ratio (ICER), comparing the vaccine to the less effective vaccine, exceeds the ICER of the less effective vaccine as compared to the alternative 'no vaccination'. The general principle is explained below (see 'Rationale'). | ||
The importance of alternative assumptions about protection against individual serotypes were assessed in a sensitivity analysis. Several 'modifications' for PCV10 and PCV13 were considered, regarding assumptions about the extent of indirect protection against serotypes | The importance of alternative assumptions about protection against individual serotypes were assessed in a sensitivity analysis. Several 'modifications' for PCV10 and PCV13 were considered, regarding assumptions about the extent of indirect protection against serotypes |
Revision as of 09:22, 17 September 2014
Moderator:Nobody (see all) Click here to sign up. |
|
Upload data
|
In Opasnet many pages being worked on and are in different classes of progression. Thus the information on those pages should be regarded with consideration. The progression class of this page has been assessed:
|
This page needs a curator. Learn more about curating Opasnet pages. |
Question
How to identify the most cost-effective pneumococcal conjugate vaccine to the national immunisation programme?
- The health benefit (effectiveness) of the pneumococcal infant immunisation programme is assessed by the expected gain in Quality-Adjusted Life Years (QALYs), corresponding to the expected reduction in the annual number of invasive pneumococcal disease in the whole Finnish population.
- The perspective of the analysis is that of the health care provider.
- The analysis is based on incremental cost effectiveness
Answer
A general approach to answer the question is based on the concept of incremental cost-effectiveness. For example, if there are only two vaccines to be compared, the more effective (and more expensive vaccine) is said to be more cost-effective if the incremental cost effectiveness ratio (ICER), comparing the vaccine to the less effective vaccine, exceeds the ICER of the less effective vaccine as compared to the alternative 'no vaccination'. The general principle is explained below (see 'Rationale').
The importance of alternative assumptions about protection against individual serotypes were assessed in a sensitivity analysis. Several 'modifications' for PCV10 and PCV13 were considered, regarding assumptions about the extent of indirect protection against serotypes 3, 6A, 6A, and 19A. A detailed account of the sensitivity analysis is on page Cost_effectiveness_sensitivity. These analyses included determining the difference in the QALYs gained under PCV10 and PCV13.
In summary, if PCV13 does not induce population-level (i.e. indirect) effects on serotype 3, the difference between PCV10 and PCV13 in quality adjusted life years (QALYs) gained and medical costs are relatively minor. Different assumptions about the roles of 6A protection by PCV10 and 6C protection by PCV13 lead to different preferences, with minor absolute differences in QALYs with respect to the overall effectiveness (QALYs gained) due to PCV vaccination.
Therefore, in view of the intrinsic uncertainties in the evaluation, PCV10 and PCV13 can be regarded as equally effective. This also means that incremental cost effectiveness ratios do not need to be calculated.
Evalution tool
The following programme can be used to calculate the incremental cost effectiveness ratios (ICERs) for two alternative vaccination programmes. The input required is:
(a) the serotype compositions of the two vaccines to be compared (the defaults are PCV10 and PCV13), and
(b) the prices per dose for the two vaccine products.
The computation utilises the epidemiological model[1] to predict the annual number of invasive pneumococcal disease (IPD) under both vaccination programmes and, for comparison, for the scenario 'no vaccination'. The summary table presents the ICERs. The vaccine programme with the lower ICER is identified as the more cost-effective of the two alternatives. Note, that some of the ouput is irrelevant if the vaccine programme is cost saving (i.e, if savings in medical costs exceed vaccine programme cost).
N.B. Some assumptions applied int the sensitivity analysis cannot be realised with the current version of the programme. In particular, there is currently no option to include direct protection only (i.e. vaccine efficacy for the vaccinated cohorts only) for individual serotypes. However, the sensitivity analyses show that the difference between 'direct protection only' and 'no protection at all' is usually not decisive for the overall effectiveness of conjugate vaccination. In other words, the most important assumptions concers indirect protection.
- Instructions for user: Choose the desired vaccine compositions and their prices and then press "Run code".
The results of the cost-effectiveness analysis will be displayed on a separate tab.
Rationale
Vaccination programmes are ranked in ascending order according to their effectiveness. The effectiveness is measured as the expected reduction in invasive pneumococcal disease, as predicted by the epidemiological model. Alternatives for which there is at least one other alternative with lower cost and better effectiveness are first excluded. Each programme ('A') is then compared to the next more effective programme ('B') by the incremental cost-effectiveness ratio (ICER)R↻ :
Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle ICER = \frac{(C_B-S_B) - (C_A-S_A)}{E_B-E_A},}
where C is the price of the vaccination program, S is the savings in health care costs (as compared to strategy 'no vaccination') and E is the savings in QALYs (as compared to 'no vaccination'). Any programme that is followed by a (more effective) programme with a smaller ICER (i.e. one which produces an additional unit of effect with lower cost) is dropped off from further consideration. The ICERs are then re-calculated and the procedure repeated as many times as needed to eventually identify the most cost-effective alternative. For a tutorial on incremental cost effectiveness analysis, see Phillips (2009) [2].
Costs
Health care resource use in secondary health care, per IPD case and sequelae after meningitis, were estimated from the Hospital Discharge Register (2000-2006). For each meningitis and bacteremia case, an episode of care was constructed by linking the outpatient visits and inpatient hospitalizations, using the unique personal identity code. The case fatality ratio (CFR) for IPD was obtained from a Finnish study [3]. The unit costs for hospitalizations and outpatient visits were estimated based on individual-level cost accounting data from one hospital district. Other unit cost estimates were mainly taken from a widely used national price list for the unit costs of health care in Finland. The costs were presented in 2012 prices and were evaluated from the health care provider perspective. Future costs and benefits were discounted at 3% per annum.
Data
Summary table of the data applied in the cost-effectiveness analysis. Note, that the cost-effectiveness analysis is based on age-year (0-100) specific data on IPD and life years lost.
1. QALY_menin = QALY losses due to meningitis incl. sequlae (in years, *) 2. QALY_bact = QALY losses due to bacteremia (in years, *) 3. CFR = Case fatality ratio for meningitis and bacteremia 4. Life_y_lost = Life years lost due to IPD (mengitis or bacteremia, *) 5. Cost_ menin = Medical costs attributed to meningitis incl. sequlae (in euros *) 6. Cost_ bact = Medical costs attributed to bacteremia (in euros *) 7. Menin_proportion = Proportion of meningitis cases of all IPD cases (*) a discount rate of 3%/year was applied in all calculations
Age class | QALY_men | QALY_bac | CFR | Life_y_lost | COST_men | COST_bac | Menin_proportion |
<5 years | 0.22 | 0.0079 | 0.014 | 31.1 | 22 070 | 1 986 | 0.037 |
5-64 years | 0.16 | 0.0079 | 0.112 | 20.7 | 26 488 | 9 000 | 0.046 |
65+ years | 0.08 | 0.0079 | 0.196 | 9.4 | 21 529 | 6 823 | 0.019 |
- Note: The above table lists averages within each age class. Cost-effectiveness analysis is based on age year -specific values.
Age group | QALY_meningitis | QALY_bacteremia | Life_years_lost | Cost_meningitis | Cost_bacteremia |
0-4y | 0.83 | 0.75 | 43.64 | 81 591 | 189 444 |
5-64y | 2.89 | 2.90 | 895.01 | 470 949 | 3 308 515 |
65+y | 0.51 | 2.34 | 555.60 | 125 916 | 2 020 437 |
Computation
Variable initiation (Only for developers)
Cost calculation (Only for developers)
Sensitivity
The effects of alternative vaccine compositions on the outcomes of the cost-benefit analysis were assessed. Several modifications for PCV10 and PCV13 were considered. Conclusion: The assumption about serotype 3 in PCV13 is crucial. In addition, assumptions about the role of 6A in PCV10 is important. For results, see Cost_effectiveness_sensitivity.
If serotype 3 is not included as a vaccine type in PCV13, then the differences between PCV10 and PCV13 in quality adjusted life years (QALYs) gained and medical costs are relatively minor. Therefore, in view of the intrinsic uncertainties in the model, PCV10 and PCV13 can be regarded as equally effective.
See also
References
- ↑ Nurhonen M, Auranen K (2014) Optimal Serotype Compositions for Pneumococcal Conjugate Vaccination under Serotype Replacement. PLoS Comput Biol 10(2): e1003477. doi:10.1371/journal.pcbi.1003477
- ↑ Phillips C (2009) What is cost-effectiveness? What is...? series. Hayward Medical Communications.
- ↑ Klemets et al. (2008) Invasive pneumococcal infections among persons with and without underlying medical conditions: implications for prevention strategies. BMC Infect Dis. 2008 Jul 22;8:96.
Related files
Comment the content