Mispredicting and misremembering: patients with renal failure overestimate improvements in quality of life after a kidney transplant.
OBJECTIVE
People tend to overestimate the impact that future events will have on their quality of life. In the case of a medical treatment like kidney transplant, this should result in biased predictions--overestimates of how much the transplant will benefit quality of life. The authors surveyed kidney transplant patients, both before and after transplant, to test whether they would overestimate the benefits of a successful transplant for their quality of life.


METHODS
The authors interviewed 307 patients on a waiting list for cadaveric renal or renal-pancreatic transplant, and 195 patients one year after a successful transplant. A sub sample of patients were interviewed both before and after transplant.


METHODS
The survey included measures of quality of life, both in terms of an overall estimate (0-100), and across sub domains, including health, employment, and travel.


RESULTS
Cross-sectional results suggested that overall quality of life improved after transplant, but the predictions of pretransplant patients overestimated the magnitude of the improvement (p < .01). In addition, patients predicted large improvements in specific life domains that did not change. These results were confirmed in longitudinal, prospective analyses. Additional analyses showed that posttransplant patients recalled their pretransplant quality of life to be much lower than what they had reported at the time.


CONCLUSIONS
Consistent with an impact bias, patients substantially overestimated the benefits of a successful kidney transplant, both in terms of predictions of life after treatment, and in their memories of QOL before the transplant.
Smith
Dylan
D
VA Health Services Research & Development Center of Excellence, VA Ann Arbor Healthcare System and Center for Behavioral and Decision Sciences in Medicine, University of Michigan, MI, USA. dylsmith@umich.edu
Loewenstein
George
G
Jepson
Christopher
C
Jankovich
Aleksandra
A
Feldman
Harold
H
Ubel
Peter
P
D000339:Affect; D001294:Attitude to Health; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008568:Memory; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology*; D051437:Renal Insufficiency / Q000523:psychology* / Q000601:surgery*; D011795:Surveys and Questionnaires