High agreement of self-report and physician-diagnosed somatic conditions yields limited bias in examining mental-physical comorbidity.
OBJECTIVE
To quantify the misclassification bias of self-reported somatic diseases and its impact on the estimation of comorbidity with mental disorders.


METHODS
Data were drawn from the German National Health Interview and Examination Survey (N=7,124), which assessed both self-reported and physician-diagnosed somatic diseases. Eight chronic diseases were examined: coronary heart disease, heart failure, asthma, chronic bronchitis, diabetes, cancer, arthrosis, and arthritis. Mental disorders were assessed by means of the Munich-Composite International Interview.


RESULTS
The agreement of case ascertainment by patient self-report and physician diagnosis was high (kappa: 0.74-0.92), except for arthritis (0.53). False-positive and false-negative disease statuses were partly associated with age, sex, socioeconomic status, somatic comorbidities, marital status, and mood and anxiety disorders. In most conditions, the odds ratios (ORs) of comorbid mental disorders based on self-reported diseases were slightly overestimated with regard to mood disorders (relative OR: 0.91-1.38), whereas there proved to be no such trend regarding anxiety disorders (0.82-1.05). Substance disorders were partly biased without showing an interpretable trend across diseases (0.49-2.58).


CONCLUSIONS
Evaluation of mental-physical comorbidity based on self-reported and physician-diagnosed physical conditions yielded similar results, with modestly inflated ORs for mood disorders for several self-reported physical conditions.
Baumeister
Harald
H
Department of Rehabilitation Psychology and Psychotherapy, Institute of Psychology, University of Freiburg, Freiburg, Germany. baumeister@psychologie.uni-freiburg.de <baumeister@psychologie.uni-freiburg.de>
Kriston
Levente
L
Bengel
Jürgen
J
Härter
Martin
M
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D015982:Bias; D002908:Chronic Disease / Q000453:epidemiology*; D015897:Comorbidity; D003951:Diagnostic Errors / Q000706:statistics & numerical data; D004812:Epidemiologic Methods; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D012650:Self Disclosure; D012737:Sex Factors; D012959:Socioeconomic Factors; D055815:Young Adult