THE LIMITED VALUE OF ROUTINE LABORATORY ASSESSMENTS IN SEVERELY IMPAIRED NURSING-HOME RESIDENTS

Objective.-To determine the usefulness of a routine, comprehensive bat tery of laboratory tests in a severely impaired elderly nursing home p opulation. Design.-Prospective observational survey. Setting.-Skilled nursing facility wards of a geriatric and extended care veterans hospi tal. Patients.-Consecutive sample of 108 veterans with severe cognitiv e and functional impairments, who had been hospitalized at least 6 mon ths. Main Outcome Measures.-Proportions of tests categorized as screen ing, monitoring, follow-up, or diagnostic; frequency of abnormal test results, interventions warranted and performed on the basis of these a bnormalities, and beneficial or adverse effects. Results.-Of 6771 indi vidual nondiagnostic tests performed, 17.2% yielded abnormal results; of these, 33.3% were new. However, only 0.2% of tests resulted in pati ent benefit. Of 989 panels performed, 31.0% contained at least one abn ormality, but only 1.0% of panels (10 patients) yielded any benefit. O verall 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, respecti vely (P<.05 for each compared with screening panels). None of the scre ening panels detected an abnormality that led to patient benefit, comp ared with 1.0%, 1.4%, and 3.0% of monitoring, follow-up, and diagnosti c panels. Conclusions.-Routine comprehensive laboratory panels may not be warranted in the most severely impaired elderly patients in long-t erm care settings. Discontinuing true screening tests and limiting tes ting strictly to monitoring, followup, or diagnostic purposes could mi nimize the costs of laboratory assessment without losing its potential benefits.