Thirty down, only ten to go?! Awareness and influence of a 10-year time frame in TTO

1. Thirty down, only ten to go?! Awareness and influence of a 10-year time frame in TTO Floor van Nooten, Xander Koolman, Werner Brouwer A paper introduced by Jan van Busschbach LoLa, xx May 2010

2. Time Trade-Off • Wheelchair • With a life expectancy: 50 years • How many years would you trade-off for a cure? • Max. trade-off: 10 years • QALY(wheel) = QALY(healthy) • Y * V(wheel) = Y * V(healthy) • 50 V(wheel) = 40 * 1.00 • V(wheel) = 0.80

3. Does the time frame matters? 1. Wheelchair, life expectancy: 50 years • Max. trade-off: 10 years • 50 V(wheel) = 40 * 1.00 • V(wheel) = 0.80 2. Wheelchair, life expectancy: 10 years • Max. trade-off: 2 years • 10 V(wheel) = 8 * 1.00 • V(wheel) = 0.80 3. Wheelchair, normal life expectancy: 50 years, but trade-off limited to 10 years • After 10 years you die anyway • Irrespectively of real live expectancy • Research justification: • Is option 3 the same as 1 and/or 2?

4. Indeed time frames matters… • From earlier research 1. Life time, long life expectancy: the lowest values 2. Life time, short life expectancy: higher values 3. Forced short life expectancy: even higher values • That is: If indeed subjects follow instructions…. • Given that the instructions are complex… • Especially with forced short life expectancy … • Research questions • Forced short life is often used…. • Do subjects adhere to forced short life expectancy instructions?

5. Different “emphasis” on instruction forced short life • RCT, using 10 years life year framing • N = 656 • Internet survey • Q1: Control condition • No addition emphasis on 10 years life • Debriefing afterwards: “What were you thinking?” • Q2: Experimental condition • Added emphasis on forced short life • 3 EQ-5D health state valuations with TT0 • TTO1: 21211 • TTO2: 22221 • TTO3: 33312

6. Results: table 2 Less subjects start trade off when explicit instruction about 10 year survival are given Trade offs are higher when explicit instruction about 10 year survival are given

7. Additional results • Debriefing control condition Q1 • 43% did not think of forced short life… • Those who remembered instructions… • TTO1: 21211…. • Lower values… not what might be expected • TTO2: 22221…. • Higher values… but (univariate) not significant • TTO3: 33312…. • Higher values… but (univariate) not significant • Multivariate ONLY TT02 & TTO 3… • Significant results

8. Additional results • Higher education: lower values • Known already… • No age effect • Known already… • Men trade off more: lower values • New

9. Conclusions • Subject forget instructions • In the control condition, forced short life time is forgotten in 43% of cases • Instructions matter • Higher values with explicit instructions • Those who forget, give lower values • Influence back ground variables • Women (mothers) trade off less • Higher education trade of more • Main conclusion: • “These findings emphasize the importance of expected and implied life expectancy in TTOs and raise important questions regarding the optimal design of TTO exercises.”

10. Some problems… • Generalizability is over stretched • 10 years life frame is rare • Design is not a replication of that rare design • The relevance is over stretched • Difference found are small • Only in states with a low value • Back ground variables no part of research question • No testing whether 10 years is a good thing • Main conclusion should be: • “These findings emphasize the importance of explicit instructions of implied life expectancy in TTOs with bad health states” • In stead of • “These findings emphasize the importance of expected and implied life expectancy in TTOs and raise important questions regarding the optimal design of TTO exercises.”

11. 10 years life frame is rare • Forced short life is only used in some cases • “Commonly, time trade-off (TTO) exercises use a 10-year time horizon,…” • “conventional TTO” • But this is only true for EQ-5D, MVH-protocol • MVH-protocol is used a lot…. • In EQ-5D and its translations • But others use different time frames • SF-6D (SG) • AQoL ? • HUI ? • 12D (VAS) • Disease specific : IPSS, IIEF, …life time • Provide indications for which instruments it applies…

12. Design is not a replication of the relevant earlier research • MVH-protocol differs from current design • Is mentioned ones… • MVH is interview, not internet based • There are explicit instruction in the interview about the 10 years • MVH used visual add • The 10 life year span is visual • MVH allows for negative values

13. Explicit instructions

14. Visual add (prop)

15. The design does not replicate “This point is emphasized by the fact that the utility scores obtained in our study are relatively high, when for instance compared to MVH_A1 scores…”

16. Are the differences relevant? No statistical significance No relevant difference Could be relevant

17. Man trade more than women • The “mother hypothesis” • “Such response modes might be related to the position women have or envisage to have in life (e.g., as mothers). “ • Neo-Darwinism • Not the research question • Girls just wanna have fun… • Cyndi Lauper (1983) • Paul Kind • Cyndi is right… • British Medical Journal 1998;316:736-41.

18. Fishing party….. • Debriefing control condition Q1 • 43% did not think of forced short life… • Those who remembered instructions… • TTO1: 21211…. • Lower values… not what might be expected • TTO2: 22221…. • Higher values… but (univariate) not significant • TTO3: 33312…. • Higher values… but (univariate) not significant • Multivariate ONLY TT02 & TTO 3… • Significant results… • Leave this out…..

19. Conclusions • Subject forget instructions • In the control condition, forced short life time is forgotten in 43% of cases • Instructions matter • Higher values with explicit instructions • Main conclusion: • “These findings emphasize the importance of explicit instructions of implied life expectancy in TTOs with bad health states”