Personality and physician-assessed illness burden in older primary care patients over 4 years.

BACKGROUND: Personality traits have been associated with physician-rated illness burden cross-sectionally, but longitudinal associations between personality and objective medical morbidity remain unclear.
PURPOSE: To examine associations between personality and physician-rated illness burden 4 years prospectively in older primary care patients.
METHOD: At baseline, patients (average age: 75, SD: 6.6, 62% female) completed the NEO-Five Factor Inventory. At baseline and 4 yearly follow-ups, a physician completed the Cumulative Illness Rating Scale on the basis of medical records.
RESULTS: Linear mixed-effects models revealed that higher neuroticism and lower conscientiousness predicted worse average illness burden longitudinally. Relatively disagreeable persons (25th percentile) accumulated morbidity at a 33% faster rate than agreeable (75th percentile) peers. At the final follow-up, a person at the 75th percentile of neuroticism and the 25th percentile of conscientiousness and agreeableness showed morbidity comparable to a peer of average personality but 10 years older. An individual at the 25th percentile of neuroticism and 75th percentile of conscientiousness and agreeableness showed end-point illness burden comparable to a peer of average personality but 10 years younger. Twenty-one percent of the morbidity associated with neuroticism was explained by total cholesterol. History of hypertension, smoking, alcohol/drug abuse, and affective symptoms of depression each explained 10% or less of the other observed personality effects.
CONCLUSION: Personality plays a nontrivial role in healthy aging among older persons. Brief personality assessment may identify at-risk older persons for closer monitoring, enhance the accuracy of medical prognosis, and provide clues for clinical interventions to promote better health.