BACKGROUND: Cognitive screening is currently recommended as part of the routine evaluation in the primary care setting of older patients because of the high prevalence and social costs of dementia. However, previous studies have shown frequent lack of recognition of the dementia syndrome and high rates of missed dementia diagnosis both in the local as well as developed countries especially in primary care visits. Hence, it is recognized that there is a need for a simple screening instrument that can empower primary care practitioners and internists in general to initiate screening and diagnose dementia in their offices since they are the ones who sees the bulk of older patients. The Time and Change Test (TCT), developed by Froehlich, et al, is a simple, rapid performance-based test which assesses the patient's ability to tell time and make change. It has been previously validated for the detection of dementia both in the inpatient and outpatient population. Previous studies also reported it to be accurate, reliable and acceptable by elderly persons. However, the usefulness and applicability of TCT in our locality is yet to be tested.

OBJECTIVE: To determine the reliability and validity of 'Time and Change Test as a screening tool for dementia In patients 60 years old and above seen at the Memory Center of St. Luke's Medical Center.

METHODOLOGY: Consecutive patients referred to the i Memory Center for cognitive evaluation from March 2003 to September 2004 were included in the study. Patients underwent a battery of psychological tests administered by a trained psychologist who were blinded to the diagnosis of the neurologist using the DSM-IV criteria and the stage of dementia using the Clinical Dementia Rating Scale (CDR-4). The neurologist interviewed the patient, the relatives or caregivers separately for collateral information to establish the patient's level of functioning and rate of cognitive decline and the presence of behavioral symptoms. The Time and Change Test was added to the psychological tests administered by the psychologist. The patient was asked to tell the time of a clock face set at 11:10. Two tries are allowed for a correct response within a 60-second period of time. Next, patient was asked to make a change. A set of three Php 20 bills, seven Php 10 bills and seven Php 5 bills were placed before the patient. The patient was then asked to give back a total of Php 100 change and was allowed two tries for a correct change within a two minute period. Incorrect responses in either or both tasks are scored as positive, indicating the need for further evaluation for the presence of dementia. Reliability of TCT was tested in both demented and normal patients. The clinical diagnosis by the neurologist based on the DSM-IV criteria was used as the gold standard.

RESULTS: The reliability of TCT was tested in 31 patients (n=31), with inter-observer agreement of 100%. The test-retest also showed high reliability. The validity of TCT was tested on total of 84 patients. The sensitivity was at 65.45 percent and specificity of 97 percent. Positive predictive value was 97.30 percent.

CONCLUSION: Time and Change Test is a reliable assessment tool with high positive predictive value for the presence of dementia. Because of its being simple and easy to administer, it can help primary care physicians screen for cognitive decline in older Filipinos.