Assessing the reliability and validity of a newly developed insomnia treatment satisfaction questionnaire (ITSAT-Q)

Beyer, Andrew P.; Szeinbach, Sheryl L.; Seoane-Vazquez, Enrique C.; Gliem, Joseph A.; Doan, Justin; Wal, Gregory S. Vander; Lichstein, Kenneth L.

doi:10.1016/j.sleep.2009.12.010

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Volume 11, Issue 8 , Pages 766-771, September 2010

Assessing the reliability and validity of a newly developed insomnia treatment satisfaction questionnaire (ITSAT-Q)

Andrew P. Beyer
- College of Pharmacy, The Ohio State University, Columbus, OH, USA
- Corresponding author at: College of Pharmacy, The Ohio State University, 500 W 12th Ave., Columbus, OH 43210, USA.
Sheryl L. Szeinbach
- College of Pharmacy, The Ohio State University, Columbus, OH, USA
Enrique C. Seoane-Vazquez
- College of Pharmacy, The Ohio State University, Columbus, OH, USA
- College of Public Health, The Ohio State University, Columbus, OH, USA
Joseph A. Gliem
- College of Food, Agricultural & Environmental Sciences, The Ohio State University, Columbus, OH, USA
Justin Doan
- Genentech, formerly, Takeda Pharmaceuticals North America, Inc., One Takeda Parkway, Deerfield, IL, USA
Gregory S. Vander Wal
- Department of Psychology, The University of Alabama, Tuscaloosa, AL, USA
Kenneth L. Lichstein
- Department of Psychology, The University of Alabama, Tuscaloosa, AL, USA

Received 2 July 2009; received in revised form 11 December 2009; accepted 18 December 2009.

Abstract

Purpose

To produce a valid insomnia treatment satisfaction questionnaire (ITSAT-Q) to assess treatment satisfaction with pharmacotherapy for use in patients with insomnia.

Patients and methods

Items developed for a self-administered questionnaire were analyzed using exploratory factor analysis (EFA), which produced 5 dimensions. Confirmatory factor analysis was used to verify results from EFA, and structural equation modeling was used to test the hypothesized relationship among the dimensions. Data were collected from patients as part of a Sleep Research Project from January 2008 until October of 2008.

Results

Approximately 69.8% of the sample (n=298) was female. Item-to-total correlations were 0.66 for convenience, ranged from 0.52 to 0.62 for expectations, from 0.54 to 0.69 for value, from 0.50 to 0.57 for effectiveness, and from 0.58 to 0.72 for treatment satisfaction. All standardized parameter estimates from confirmatory factor analysis were significant (p<0.01). Goodness of fit measures for the final structural equation model were χ²=45.2 (d.f.=45); p=0.465; CFI=1.00; TLI=1.00; and RMSEA=0.004. Treatment satisfaction was a strong and significant predictor of value, and effectiveness was a strong predictor of treatment satisfaction (p<0.01). Expectations were a strong and equal predictor of both treatment satisfaction and value (p<0.001).

Conclusion

The ITSAT-Q provided acceptable results for instrument reliability and validity. Findings from this study will provide additional insight regarding patient perceptions of treatment satisfaction and other related therapeutic dimensions to help prescribers assess pharmacotherapy.

Keywords: Insomnia, Treatment satisfaction, Instrument development, Clinical assessment, Confirmatory factor analysis, Structural equation modeling