Table 2

Between-subject design

Source, year	Country	Population studied	Sample size	Methods of measurement	Conclusion
Riis et al, 200533	USA	Patients with end-stage renal failure (average of 3.3 years on dialysis) receiving haemodialysis treatment compared with healthy individuals imagining life under haemodialysis	49 patients, 49 healthy controls	Questionnaire of mood levels, using levels and scales (−2 to +2 scale) Ecological momentary assessment through personal digital assistants	Healthy individuals predicted a mood decrease of −1. In anticipation of dialysis compared with the measured mood of dialysis patients. Dialysis patients imagined a 0.46 higher mood score when imagining being healthy, which was 0.33 higher compared with the actual mood score of healthy controls.
Smith et al, 200620	USA	Current patients with colostomy /ileostomy compared with former patients and to healthy individuals	195 patients of whom 100 had their colostomy reversed 567 community samples recruited from an Internet panel	Survey including-Quality of Life scale Life Satisfaction scale Positive Affect/Negative Affect Scale (PANAS) Ladder scale /self-anchoring striving scale Time trade-off utility measure, (scale 0–119 months)	Former patients were willing to trade an average of 43 months of their lives in exchange for living without a colostomy, compared with 19 months for current patients. The community sample was willing to trade an average of 44 months. No significant difference was observed in quality of life between current and former patients.
Smith et al, 2009 (Part 2)17	USA	Patients waiting for kidney transplant compared with patients after kidney transplant	307	Quality of life scale (scale: 0–100) Physical and mental health functioning (Short Form Health Survey-12)	Improvement in quality of life in post-transplant patients was 12.3 points lower than predicted by pre-transplant patients.
Peeters et al, 201134	The Netherlands	Patients with rheumatoid arthritis (RA) compared with healthy individuals imagining having RA based on a health state description	124 patients and 65 healthy individuals recruited by advertisement in newspaper	Interviews and questionnaires leading to self-named domains EuroQol-5D questionnaire Illness Cognition Questionnaire	Healthy individuals ranked the EuroQol-5D dimensions 0.75% median lower compared with patients.
Goranson et al, 201735	USA	Blogs of terminally ill patients compared with forecasts of everyday people imagining themselves in a similar condition	Cancer: n=20 Amyotrophic lateral sclerosis: n=5 Healthy: n=45	Linguistic Inquiry and Word Count programme PANAS and rating scale (1-5)	Healthy forecasters used 1.7% more negative-affect words than terminal patients. This difference was not found in the use of positive-affect words.

EuroQoL-5D, EuroQoL-5 Dimension.