Variability in replies to a questionnaire on symptoms of physical illness.
D000368:Aged; D000787:Angina Pectoris / Q000175:diagnosis; D001294:Attitude to Health; D001991:Bronchitis / Q000175:diagnosis; D003327:Coronary Disease / Q000175:diagnosis; D003933:Diagnosis; D006801:Humans; D008487:Medical History Taking; D008875:Middle Aged; D010808:Physical Examination; D011795:Surveys and Questionnaires