An evaluation of the adequacy of outpatient monitoring of thyroid replacement therapy

Authors

  • Henry Thomas Stelfox MD,

    Corresponding author
    1. PhD program in Health Policy at Harvard University, Boston, MA, USA
    2. Department of Medicine at the University of Toronto, Toronto, Canada
      Dr Henry Thomas Stelfox
      Division of General Medicine
      Department of Medicine
      Brigham and Women's Hospital
      1620 Tremont Street
      Boston
      MA 02120-1613
      USA
      E-mail: stelfox@fas.harvard.edu
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  • Sofia B. Ahmed MD,

    1. Department of Medicine at Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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  • Julie Fiskio,

    1. Partners Information Systems Boston, MA, USA
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  • David W. Bates MD MSc

    1. Department of Medicine at Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
    2. Partners Information Systems Boston, MA, USA
    3. Division of General Medicine at Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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Dr Henry Thomas Stelfox
Division of General Medicine
Department of Medicine
Brigham and Women's Hospital
1620 Tremont Street
Boston
MA 02120-1613
USA
E-mail: stelfox@fas.harvard.edu

Abstract

Objectives  Hypothyroid patients managed with excessive or insufficient thyroid replacement therapy are often difficult to clinically recognize. Monitoring may prevent or minimize the consequences of adverse drug events (ADEs). We sought to develop an explicit model of medication monitoring and to evaluate monitoring processes and ADEs in patients taking levothyroxine.

Methods  A retrospective chart review of 400 outpatients receiving levothyroxine therapy between 1 January 2000 and 1 January 2001 at a large North American tertiary care hospital. We measured the proportion of patients satisfying minimum monitoring criteria, experiencing specific monitoring errors and having levothyroxine-related ADEs. Explicit monitoring criteria were derived from the literature and through expert opinion. Adverse drug events were identified using structured implicit reviews.

Results  Overall, only 56% (95% confidence interval [95% CI] 51–62%) of the patients prescribed levothyroxine received the minimal recommended monitoring. Errors were identified at all stages of the monitoring model. Patients who received the recommended monitoring had fewer levothyroxine-related ADEs (1% vs. 6%, P = 0.013) than those who did not. Minority status (white people 2% vs. black people 4% vs. Hispanics 14%, P = 0.023) and primary language (English 3% vs. Non-English 20%, P = 0.002) were the patient characteristics associated with levothyroxine-related ADEs.

Conclusion  Only half of outpatients taking levothyroxine at one tertiary care hospital received the recommended monitoring during one year of follow-up. Levothyroxine-related ADEs were more frequent in patients with lower-quality monitoring and in minorities and non-English speakers.

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