Psychiatric diagnosis in the elderly referred to a consultation-liaison psychiatry service in a general geriatric hospital in Japan.

AIM: Because depression is a common disorder in later life, elderly patients with delirium can be misdiagnosed as having depression. This study aimed to compare psychiatric diagnoses in the elderly made by referring doctors and psychiatrists.
METHOD: Consecutive non-psychiatric inpatients aged 65 years or older that were referred to a consultation-liaison (C-L) psychiatry service of a general hospital in Japan were enrolled. An attending psychiatrist recorded the physical and psychiatric diagnoses of the referring doctors, reason for referral, psychotropic medication and sociodemographics. The psychiatrist recorded the psychiatric diagnosis after discussion with another psychiatrist in the C-L psychiatry service. A researcher categorized the diagnoses of the referring physicians and psychiatrists as F0 (organic brain syndrome), F1 (mainly alcoholism), F2/3 (mainly depression) and F4/5 (neurosis/insomnia) using The International Classification of Mental and Behavioural Disorders, Tenth Revision (ICD-10). The degree of agreement between doctors' and psychiatrists' diagnoses was estimated for each F category using kappa statistics.
RESULTS: Of the 192 referred inpatients, 172 were enrolled (79 [45.9%] men; mean age 81.6 ± 7.8 years). Concordance of diagnosis between doctors and psychiatrists was achieved for F0, F1, F2/3 and F4/5, resulting in kappa statistics of 0.47, 0.27, 0.28 and 0.32, respectively. The psychiatrists in this survey diagnosed 12 cases of delirium and four cases of psychoactive substance-use disorders in 23 cases of depression diagnosed by the referring doctors.
CONCLUSION: The referring doctors in this survey had an insufficient level of diagnostic accuracy for psychiatric disorders. Delirium and psychoactive substance-use disorders were often misdiagnosed as depression.