Comparison of the two studies
| CGP | DARTs | |
|---|---|---|
| CGP=clinical guidance programme; DARTs=Decision Analysis in Routine Treatment study; HRT=hormone replacement therapy; QALE=quality adjusted life expectancy. | ||
| Setting/decision | Oophorectomy at time of hysterectomy | Warfarin to prevent stroke in atrial fibrillation |
| One off decision | Revocable decision | |
| Long term outcomes | Shorter term outcomes | |
| Participants | Younger women (40–55 years) | Older people (men and women) |
| Delivered by | Researcher/facilitator | Responsible clinician |
| Value elicitation and incorporating patient preferences | Generic value elicitation (EuroQuol) | Specific value elicitation for both outcomes + treatment health states |
| Standard gamble (SG) on a single generic health state plus time trade off (but user can opt to choose a method they prefer from “time trade off”, SG or visual analogue scale) | Standard gamble only, values derived from each patient for all clinically relevant health states | |
| Opt out function to population utilities | No opt out or use of population utilities | |
| Preferences for duration of HRT treatment incorporated, but value of treatment state (i.e. “on HRT”) not derived | Value for treatment state derived and incorporated (i.e. “on warfarin”) | |
| Does not seek predisposition or final treatment preference of patient | Seeks predisposition/emerging disposition/final treatment preference of patient | |
| Patient alerted to types of task involved in advance to permit prearranged opt outs | ||
| Risk assessment and presentation | Individual risk factors elicited, incorporated into model and used to adjust output, but patient's individual risks of outcome events not presented at point of elicitation of risk factors | Individual risk factors elicited and individual risks of stroke and bleed on and off therapy made explicit to patient at the point of elicitation of risk factors |
| Does not consider impact of change in other risk factors on treatment decision (e.g. smoking/HT) | Considers impact of change in other risk factors on treatment decision (e.g. smoking/HT) | |
| Output | Gives quantitative output in QALE and life expectancy | Gives yes/no output of model |
| Output in the form of recommended treatment on basis of model | Uses model output as but one input to inform decision | |
| Effects of varying duration of HRT included as part of sensitivity analysis | No sensitivity analysis | |