The limited value of routine laboratory assessments in severely impaired nursing home residents

To determine the usefulness of a routine, comprehensive battery of laboratory tests in a severely impaired elderly nursing home population.

Prospective observational survey.

Skilled nursing facility wards of a geriatric and extended care veterans hospital.

Consecutive sample of 108 veterans with severe cognitive and functional impairments, who had been hospitalized at least 6 months.

Proportions of tests categorized as screening, monitoring, follow-up, or diagnostic; frequency of abnormal test results, interventions warranted and performed on the basis of these abnormalities, and beneficial or adverse effects.

Of 6771 individual nondiagnostic tests performed, 17.2% yielded abnormal results; of these, 33.3% were new. However, only 0.2% of tests resulted in patient benefit. Of 989 panels performed, 31.0% contained at least one abnormality, but only 1.0% of panels (10 patients) yielded any benefit. Overall usefulness was related to the purpose of the testing, with 31.5% of screening tests yielding abnormalities, compared with 45.5%, 78.2%, and 68.7% of monitoring, follow-up, and diagnostic panels, respectively (P < .05 for each compared with screening panels). None of the screening panels detected an abnormality that led to patient benefit, compared with 1.0%, 1.4%, and 3.0% of monitoring, follow-up, and diagnostic panels.

Routine comprehensive laboratory panels may not be warranted in the most severely impaired elderly patients in long-term care settings. Discontinuing true screening tests and limiting testing strictly to monitoring, follow-up, or diagnostic purposes could minimize the costs of laboratory assessment without losing its potential benefits.