Research Article
Shortening of the Pittsburgh Sleep Quality Index Survey Using
Factor Analysis
Oluremi A. Famodu,
1
Makenzie L. Barr,
1
Ida Holásková,
2
Wenjun Zhou,
3
Jesse S. Morrell,
4
Sarah E. Colby,
5
and Melissa D. Olfert
1
1
Division of Animal and Nutritional Sciences, Davis College of Agriculture, Natural Resources, and Design, West Virginia University,
Morgantown, WV, USA
2
Ofce of Statistics, West Virginia Agriculture and Forestry Experiment Station, West Virginia University,
4100 Agricultural Sciences Building, P.O. Box 6108, Morgantown, WV 26506-6108, USA
3
University of Tennessee, Knoxville, 916 Volunteer Boulevard, UT SMC 247, Knoxville, TN 37996, USA
4
University of New Hampshire, Kendall Hall, Room 115, 129 Main Street, Durham, NH 03824, USA
5
University of Tennessee, Knoxville, 1215 W. Cumberland Avenue, 229 Jessie Harris Building, Knoxville, TN 37996, USA
Correspondence should be addressed to Melissa D. Olfert; melissa.olfert@mail.wvu.edu
Received 16 November 2017; Accepted 6 March 2018; Published 15 April 2018
Academic Editor: Michel M. Billiard
Copyright © 2018 Oluremi A. Famodu et al. Tis is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
Objective/Introduction. Lengthy surveys have the potential to burden users and can lead to inaccuracies. Conducting analyses to
shorten existing validated surveys is benefcial. Te objective, therefore, was to shorten the Pittsburgh Quality Sleep Index (PSQI) for
young adults. Methods. PSQI data from 1246 college students were used. An exploratory factor analysis (FA) was utilized to shorten
survey afer dropping select items. Nonparametric correlation analysis (Spearman’s rho) was conducted between the global sleep
scores of the shortened and original surveys. Agreements tests (Kappa and McNemar’s test) measured the agreement of the surveys
and sensitivity and specifcity were evaluated. Results. Six factors were examined using maximum likelihood factoring method,
applying squared multiple correlations with Promax rotation to allow for correlated variables. FA with six factors explained 100% of
shared variance based on eigenvalues and accounted for 61% of variability based on variables. Te FA resulted in 13 selected questions
(“shortPSQI”), corresponding to 5 of the 7 components of the original survey. High correlation was found between the global scores
of the original survey and the “shortPSQI” (rho = 0.94, < 0.001). When the global score was converted to the categorical variable
of good or poor sleepers, the agreement test indicated strong agreement (Kappa 0.83, 95% CI 0.79–0.86, < 0.0001). Conclusion.
Te validated, 19-item PSQI survey was shortened to 13 items. Tests of correlation and agreement indicate the “shortPSQI” may be
an acceptable alternative to the original survey for young adults. Clinical Trial Registration. Data for this study was taken from the
Get Fruved study, registered on October 21, 2016, on clinicaltrials.gov (NCT02941497).
1. Introduction
Research conducted in higher education institutions ofen
relies on survey data to gather indicators of health (e.g.,
health behavior, health knowledge, and health practices).
However, response burden is one potential issue that limits
the amount and accuracy of data collected from survey
distribution. Factors associated with response burden are
questionnaire length, cognitive ability to complete the survey,
and type of questionnaire interface [1]. In particular, lengthy
surveys result in fewer respondents starting or completing
questionnaires [2] and diferences in processing questions
near the end, which can lead to omitted information [3]
and/or inconsistent answers [4]. Given the need to maintain
high quality research, investigators have begun to explore
ways to decrease response burden, including reducing the
number of items in existing questionnaires [5]. Some studies
take a smaller subset of questions from validated surveys
with the intention of reducing response burden [6]. However,
these truncated surveys must be revalidated before being
used in research.
Hindawi
Sleep Disorders
Volume 2018, Article ID 9643937, 9 pages
https://doi.org/10.1155/2018/9643937