The routine use of investigations in elderly psychiatric patients.

The use of investigations was studied in all new admissions (n = 167) to a psychiatric unit for the elderly over an 18-month period. Twenty per cent of the tests revealed abnormalities confirming the relatively high prevalence of physical pathology in this population. However, only 4% of the investigations requested influenced further management. It is suggested that full blood count, serum folate, urea and electrolytes and urine culture should be performed routinely, but that other investigations might be ordered selectively.