THE VALIDITY OF THE JUDGMENT OF GENERAL-PRACTITIONERS ON DEMENTIA

This study focused on two aspects of the validity of the judgement of general practitioners (GPs) on dementia: criterion and construct valid ity. The Cambridge Mental Disorders of the Elderly Examination (CAMDEX ) was used as the gold standard to assess the specificity and sensitiv ity of the GP judgement. Construct validity was studied by comparing p atient characteristics that were hypothesized to predict the GP judgem ent by predictive variables from our data, using logistic regression a nalysis. In addition, the patient characteristics that predicted a 'fa lse positive' or 'false negative' GP judgement were determined. Thirty -six GPs participated in the study, as well as 475 community-dwelling patients. The overall agreement between CAMDEX diagnosis and GP judgem ent was 72%. The sensitivity and specificity of the GP judgement in ma king the distinction between 'normal cognitive functioning + minimal d ementia' versus 'mild + moderate + severe dementia' were 52% and 94% r espectively. Patient characteristics that predicted the GP judgement o n dementia were: age, sex, cognitive functioning, IADL functioning (In strumental Activities of Daily Living) and memory complaints. All thes e characteristics, except sex, were hypothesized to do so. Patient cha racteristics predicting a 'false positive' or a 'false negative' GP ju dgement were cognitive and IADL functioning. Both groups of patients ( 'overdiagnosed' and 'missed' by the GP) belong to the in-between group with some impaired functioning. The finding that impaired IADL functi oning is so important in the GP's judgement reflects the significance of dementia diagnosis in general practice: a starting point for adequa te care.