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

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*) 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 714 days later, and also completed other measures of treatment adherence and treatment satisfaction at baseline. Main outcome measures: SMIGHTy reliability (inter-item and testretest) and external validity (association with other study measures) were assessed. Results: Analyses revealed good inter-item agreement and testretest 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.