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Intention-to-Treat Analyses in Behavioral Medicine Randomized Clinical Trials

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Abstract

Background

Intention-to-treat (ITT) is an analytic approach where all randomized participants are included in analyses and in their originally assigned condition, regardless of adherence or protocol deviation.

Purpose

The present study aimed to determine whether reporting and correct use of ITT in behavioral medicine randomized clinical trials (RCTs) published in behavioral journals has improved in recent years.

Method

ITT and related analytic conventions were examined in behavioral medicine RCTs (N = 87) published in Annals of Behavioral Medicine, Health Psychology, and the Journal of Consulting and Clinical Psychology in the years 2000–2003 and then again in 2006–2007. Logistic regression analyses tested whether ten indicators associated with ITT were being used increasingly over time. Also tested was whether reporting and correct use of ITT improved following the adoption of Consolidated Standards of Reporting Clinical Trials (CONSORT) statement.

Results

Results revealed that less than half of RCTs (42%) used ITT analyses correctly. Over time, reporting of sample size estimation and primary outcome as well as use of the term “ITT” to describe analyses improved; however, correct implementation of ITT did not. Improvement was not specifically attributable to CONSORT adoption.

Conclusion

Investigators’ claims of using ITT analyses have increased over time, but correct use of ITT has not.

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Acknowledgment

This paper represents work undertaken on behalf of the Society of Behavioral Medicine’s Evidence-Based Behavioral Medicine Committee.

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Authors and Affiliations

  1. Division of Preventive and Behavioral Medicine, Department of Medicine, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA, 01655, USA

    Sherry L. Pagoto, Jamie S. Bodenlos & Kristin L. Schneider

  2. Department of Psychology, Oakland University, Rochester, MI, USA

    Andrea T. Kozak

  3. Edward Hines, Jr. VA Hospital, Hines, IL, USA

    Bonnie Spring

  4. Division of Epidemiology and Biostatistics, University of Illinois at Chicago, Chicago, IL, USA

    Donald Hedeker

  5. Feinberg School of Medicine, Northwestern University, Chicago, IL, USA

    Bonnie Spring

  6. University of Chicago, Chicago, IL, USA

    Priya John

Authors
  1. Sherry L. Pagoto
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  2. Andrea T. Kozak
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  3. Priya John
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  4. Jamie S. Bodenlos
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  5. Donald Hedeker
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  6. Bonnie Spring
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  7. Kristin L. Schneider
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Corresponding author

Correspondence to Sherry L. Pagoto.

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Pagoto, S.L., Kozak, A.T., John, P. et al. Intention-to-Treat Analyses in Behavioral Medicine Randomized Clinical Trials. Int.J. Behav. Med. 16, 316–322 (2009). https://doi.org/10.1007/s12529-009-9039-3

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  • DOI: https://doi.org/10.1007/s12529-009-9039-3

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