Recall bias did not affect perceived magnitude of change in health-related functional status.
OBJECTIVE
It was hypothesized that within an invasively treated group and within a group that improved in angina pectoris no difference in effect size would occur between prospective and retrospective measures. Furthermore, it was hypothesized that assessment of perceived change at post-test may be invalid because of recall bias and present-state bias.


METHODS
Effect sizes (as standardized response means) were used as indicators of magnitude of change. Linear structural equation analysis (with LISREL) was used to investigate the relationship between the estimates of recall accuracy and retrospectively assessed change.


RESULTS
No significant differences were found between prospective and retrospective measures of change over time in health-related functional status. Recall bias was not associated with retrospective measurement of change within a 12-week interval. An expected present-state effect was found in a structural equation model.


CONCLUSIONS
Prospective and retrospective indices of magnitude of change were similar between groups receiving treatment of known efficacy. Recall bias seems to be an acceptable risk in short-term follow-up studies.
Middel
Berrie
B
Department of Health Sciences, University Medical Center Groningen, University of Groningen, P.O. Box 196, 9700 AD Groningen, The Netherlands. b.middel@med.rug.nl
Goudriaan
Heike
H
de Greef
Mathieu
M
Stewart
Roy
R
van Sonderen
Eric
E
Bouma
J
J
de Jongste
Mike
M
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy / Q000523:psychology / Q000601:surgery*; D015906:Angioplasty, Balloon, Coronary / Q000379:methods; D001294:Attitude to Health; D015982:Bias; D002637:Chest Pain / Q000209:etiology; D001026:Coronary Artery Bypass / Q000379:methods; D004644:Emotions; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015233:Models, Statistical; D011446:Prospective Studies; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D016896:Treatment Outcome