Routine laboratory tests: helpful or just costly? (column)

Abstract

The appropriate utilization of laboratory tests was studied by a consultant pharmacist in a 72-bed geriatric nursing home over a two-year period. There was a general underutilization of drug levels to detect digoxin, phenytoin, and theophylline effects; and occasional underuse of serum electrolytes and serum creatinine to monitor diuretic effects and determine appropriate use of drugs in renal impairment. Prescriber acceptance of 95 percent (40 of 42) consultant pharmacist recommendations for lab monitoring brought changes in drug therapy with 35 of 40 cases (87.5 percent). Thirty-two of 35 (91.4 percent) prescriber-authorized lab determinations resulted in significant results that changed drug therapy dose, schedule, or necessitated additional therapy. The total cost of the requested lab work was $2,560 over the two-year study period. On the other hand, the overuse of routine multiple lab tests on a monthly to bimonthly basis yielded new information in less than five percent of repeated determinations. Routine lab work, which was in excess of the federal "indicators" frequency and situation recommendations, produced $71,566 of excessive and perhaps unnecessary health-care costs over the two-year period.

Key words: consultant pharmacy, lab tests, health-care costs.

Introduction

Previous studies in the drug-related problem series, covered in Pharmacy Briefs columns (November/ December '86 through May / June '88), have focused on medication errors, relative contraindications and adverse reactions and interactions with drugs, nutritional assessment, socioeconomic considerations, drug duplication, questionable drug efficacy, and therapeutic need for drug therapy. The purpose of the study discussed in the cuff ent column was to document the therapeutic need for adequate laboratory tests to monitor and assess the effects of drug therapy in a geriatric long-term care facility over a two-year period.

Specific objectives were to:

1. Determine the clinical utility of selected lab tests for the assessment of drug effect;