Using pilot economic models to support grant applications for clinical trials:

Transcription

1 Using pilot economic models to support grant applications for clinical trials: a case study of STRATA project Huajie Jin (Lily) Senior health economist Centre for the Economics of Mental and Physical Health (CEMPH) Huajie.jin@kcl.ac.uk

2 Why this topic is important? 1 Setting of research priority Why not? 2 R & D Health economics 3 Health technology regulation 5 Health technology management 4 Health technology assessment 2 Figure 1. Health technology: from research to implementation

3 Do I need a pilot model for my grant application? Things to consider: 1. Funding Program & Expertise of the interview panel 2. Cost of the proposed trial/intervention 3. The current extent of uncertainty over cost effectiveness, and the likelihood that economic analysis will reduce this uncertainty 4. Practical issues: Timeline, availabilities of health economists etc 3

4 Presentation outline 1. Background information 2. Pilot model Aims Methods Results 3. Discussion 4

5 Part 1. Background information 5

6 MRC call for proposals Stratified medicine is a priority area for MRC..The MRC has not pre-specified priority disease areas. Instead, applicants are invited to submit outline applications that clearly describe and justify why a particular disease area is ripe for stratified approach. Some evidence of economic benefit derived by stratification should also be included, but the MRC does not expect full health economic studies at this stage. 6

7 Comparison between current practice and proposed new treatment strategy Treatment strategies Interventions Problems TAU (Treatment as usual) ST (Stratified treatment) Atypical antipsychotics Clozapine Atypical antipsychotics Clozapine New drug MRI scan 1. At least 10% patients are treatmentresistant* (TR) 2. The treatment cost for TR is up to 10 times higher than non-tr Might be expensive to implement *: Patients who don t respond to Atypical antipsychotics or Clozapine 7

8 What do the grant applicants want to know? The potential health economic consequences of implementing the Stratified Treatment (ST) 8

9 Part 2. Pilot model 9

10 Aims of the pilot model 1). Cost-effectiveness To assess how accurate the MRI test needs to be to make Stratified Treatment (ST) cost-effective, compared with Treatment as usual (TAU). 2). Cost-impact analysis To assess the cost-impact of implementing Stratified Treatment (ST). 10

11 Methods Comparison between the NICE reference case and our methods Element of Health Technology Assessment NICE Reference case Consistent with the NICE reference case? Perspective on costs NHS and PSS Yes Type of economic evaluation Synthesis of evidence on health effects Measuring and valuing health effects Discounting Cost utility analysis with fully incremental analysis Based on a systematic review QALYs. 3.5% for both cost and health effects Yes No Yes Yes 11

12 Model structure Active psychosis Remission Death (due to suicide) Time horizon: 1 year (4 cycles) or 5 years (20 cycles) 12

13 Table 1. Excerpt of input data Variable Value Distribution Source Costs Stratification test Gamma (α=11.1, β=45.0) Range: NHS reference costs and NICE estimates for scans New drug 6.95/day Assumed fixed British National Formulary Cost of treating patients with active psychosis /day Gamma (α=11.1, β=16.8) Wang et al, 2004 Cost of treating patients in 43.17/day Gamma (α=11.1, β=3.9) Wang et al, 2004 remission Cost of productivity lost 6.19 Assumed fixed National Minimum Wage rates Clinical inputs Patients respond to Drug A 80% Assumed fixed Expert consensus 13 Patients respond to Drug B 10% Assumed fixed Expert consensus Patients respond to Drug C 10% Assumed fixed Expert consensus Patients in employment 8% Range: 5-15% Bevan et al, 2013 Suicide rates for patients with Glennie et al., 1997 active psychosis 0.07% Assumed fixed Utilities Psychotic patients in 0.83 Beta (α=10.9, β=2.2) Lenert et al., 2004 remission Patients with active psychosis 0.56 Beta (α=13.2, β=10.4) Lenert et al., 2004 Discount rates For both costs and QALYs 3.5% Fixed NICE, 2008

14 Estimates of key missing data MRI scan New drug Cost Estimated based on: NHS reference costs NICE estimates for scans BNF cost of the most expensive patent antipsychotic Effectiveness Will be informed by the model Assumed to be the same as conventional anti-psychotics 14

15 Incremental costs and effectiveness by treatment strategy (TAU vs ST) Rejected Incremental cost 70 NICE s willingness to pay Year 1 Incremental QALYs Accepted Year 5 15

16 Probability of each intervention being cost-effective after 1 year TAU ST , , , , , , , , Probability of each intervention being cost-effective after 5 years TAU ST , , , , , , , ,00

17 Part 3. Discussion 17

18 Learning points 1. Pilot economic model can be a useful tool for both grant applicants and assessors to consider the potential cost consequences of proposed clinical trials. 2. Technical difficulties: Limited time, Lack of data. Implications for future research 1. Consistency & comparability? 2. Quality control? 18