Journal of General Internal Medicine

, Volume 20, Issue 12, pp 1120–1126

Laboratory monitoring of drugs at initiation of therapy in ambulatory care

  • Marsha A. Raebel
  • Ella E. Lyons
  • Susan E. Andrade
  • K. Arnold Chan
  • Elizabeth A. Chester
  • Robert L. Davis
  • Jennifer L. Ellis
  • Adrianne Feldstein
  • Margaret J. Gunter
  • Jennifer Elston Lafata
  • Charron L. Long
  • David J. Magid
  • Joseph V. Selby
  • Steven R. Simon
  • Richard Platt
Original Articles

DOI: 10.1111/j.1525-1497.2005.0257.x

Cite this article as:
Raebel, M.A., Lyons, E.E., Andrade, S.E. et al. J GEN INTERN MED (2005) 20: 1120. doi:10.1111/j.1525-1497.2005.0257.x

Abstract

BACKGROUND AND OBJECTIVES: Product labeling and published guidelines reflect the importance of monitoring laboratory parameters for drugs with a risk of organ system toxicity or electrolyte imbalance. Limited information exists about adherence to laboratory monitoring recommendations. The objective of this study was to describe laboratory monitoring among ambulatory patients dispensed medications for which laboratory testing is recommended at therapy initiation.

DESIGN AND SUBJECTS: We conducted a retrospective cross-sectional analysis of patients in 10 geographically distributed health maintenance organizations who were newly prescribed medications with recommended laboratory test monitoring. The main outcome measure was the proportion of initial drug dispensing without recommended baseline laboratory monitoring for 35 newly initiated drugs or drug classes.

RESULTS: One hundred seven thousand, seven hundred sixty-three of 279,354 (39%) initial drug dispensings occurred without recommended laboratory monitoring. Patients without monitoring were younger than patients who had monitoring (median 57 vs 61 years, P<.001). Thirty-two percent of dispensings where a serum creatinine was indicated did not have it evaluated (range across drugs, 12% to 61%); 39% did not have liver function testing (range 10% to 75%); 32% did not have hematologic monitoring (range 9% to 51%); and 34% did not have electrolyte monitoring (range 20% to 62%) (P<.001).

CONCLUSIONS: Substantial opportunity exists to improve laboratory monitoring of drugs for which such monitoring is recommended. This study emphasizes the need for research to identify the clinical implications of not conducting recommended laboratory monitoring, existing barriers to monitoring, and methods to improve practice.

Key Words

laboratory monitoringambulatorydrug therapy

Copyright information

© Society of General Internal Medicine 2005

Authors and Affiliations

  • Marsha A. Raebel
    • 1
    • 2
    • 3
  • Ella E. Lyons
    • 1
  • Susan E. Andrade
    • 3
    • 4
    • 5
    • 6
  • K. Arnold Chan
    • 3
    • 7
    • 8
    • 9
  • Elizabeth A. Chester
    • 2
    • 3
    • 10
  • Robert L. Davis
    • 3
    • 11
    • 12
  • Jennifer L. Ellis
    • 1
  • Adrianne Feldstein
    • 3
    • 13
    • 14
  • Margaret J. Gunter
    • 3
    • 15
  • Jennifer Elston Lafata
    • 3
    • 16
  • Charron L. Long
    • 1
  • David J. Magid
    • 1
    • 3
    • 17
  • Joseph V. Selby
    • 3
    • 18
  • Steven R. Simon
    • 3
    • 9
    • 19
  • Richard Platt
    • 3
    • 7
    • 8
    • 9
    • 19
  1. 1.Kaiser Permanente of ColoradoClinical Research UnitDenver
  2. 2.School of PharmacyUniversity of Colorado at Denver and Health Sciences CenterDenverUSA
  3. 3.HMO Research Network Center for Education and Research in Therapeutics (CERTs)BostonUSA
  4. 4.Meyers Primary Care InstituteWorcesterUSA
  5. 5.Fallon FoundationWorcesterUSA
  6. 6.University of Massachusetts Medical SchoolWorcesterUSA
  7. 7.Channing LaboratoryBostonUSA
  8. 8.Brigham and Women’s HospitalBostonUSA
  9. 9.Harvard Medical SchoolBostonUSA
  10. 10.Kaiser Permanente of Colorado Pharmacy DepartmentDenverUSA
  11. 11.University of Washington Departments of Pediatrics and EpidemiologySeattleUSA
  12. 12.Group Health Cooperative Center for Health StudiesSeattleUSA
  13. 13.Kaiser Permanente Northwest Center for Health ResearchPortlandUSA
  14. 14.Oregon Health Sciences UniversityPortlandUSA
  15. 15.Lovelace Clinic FoundationAlbuquerqueUSA
  16. 16.Henry Ford Health SystemDetroitUSA
  17. 17.School of MedicineUniversity of Colorado at Denver and Health Sciences CenterDenverUSA
  18. 18.Kaiser Permanente Northern California Division of ResearchOaklandUSA
  19. 19.Harvard Pilgrim Health CareBostonUSA