An observational study to validate the Satisfaction Measure of the Injection of Growth Hormone Therapy (SMIGHTy) questionnaire

Abstract

Objective:

The objective of this study was to psychometrically evaluate a tool to measure adult caregivers’ level of satisfaction with the delivery device used to administer injections of recombinant human growth hormone (rhGH) to a child – the Satisfaction Measure of the Injection of Growth Hormone Therapy (SMIGHTy

*SMIGHTy is a trademark of Genentech, Inc., South San Francisco, CA, USA.

) questionnaire.

Research design and methods:

One hundred caregivers who administer rhGH to a child using an injection device completed the SMIGHTy questionnaire at baseline and 7–14 days later, and also completed other measures of treatment adherence and treatment satisfaction at baseline.

Main outcome measures:

SMIGHTy reliability (inter-item and test–retest) and external validity (association with other study measures) were assessed.

Results:

Analyses revealed good inter-item agreement and test–retest reliability for the SMIGHTy questionnaire. External validity, measured by associations with adherence and other measures of treatment satisfaction, was high.

Study limitations:

This study assessed only adult caregivers; the instrument was not validated for use by young or adult patients.

Conclusions:

The SMIGHTy instrument is more comprehensive than existing instruments for assessing the growth hormone treatment experience. It is multidimensional, assesses both positive and negative aspects of the treatment experience (Device Satisfaction, Negative Events, Benefits), and has separate measures of overall satisfaction and preference.

Key words::

• Injectable human growth hormone
• Patient satisfaction
• Self-report
• Validity

Transparency

Declaration of funding

This research was supported by funding from Genentech, which also provided access to the data.

Declaration of financial/other relationships

R.R.R. and M.P. have disclosed that they received research funds and consulting fees from Genentech. D.A.D., L.M., Y.X., and B.L. were employees of Genentech at the time of the study. C.P.M. has disclosed that she has no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers may have received honoraria for their review work. The peer reviewers on this manuscript have disclosed that they have no relevant financial relationships.

Acknowledgments

Author contributions: R.R.R. participated in the planning and implementation of the study, wrote the paper, reviewed and approved the paper. M.P. participated in the planning and implementation of the study, analyzed data, wrote the paper, reviewed and approved the paper. D.A.D., L.M., Y.X., and B.L. participated in the planning and implementation of the study, reviewed and approved the paper. C.P.M. participated in the implementation of the study, reviewed and approved the paper. No medical writers or statisticians were involved in the preparation of this paper.

Some material in this paper was presented at the Pediatric Endocrine Nursing Society, Indianapolis, IN, USA, April 7, 2011.

Notes

*SMIGHTy is a trademark of Genentech, Inc., South San Francisco, CA, USA.

*SMIGHTy is a trademark of Genentech, Inc., South San Francisco, CA., USA.