Relationship between an IRT-derived HRQOL Score and PA among Adults in Montana

Peter D. Hart^1,

¹Health Promotion Research, Havre, MT 59501

Cite this paper:
Peter D. Hart. Relationship between an IRT-derived HRQOL Score and PA among Adults in Montana. Journal of Physical Activity Research. 2021; 6(2):78-84. doi: 10.12691/jpar-6-2-2

Abstract

Background: Much research supports the physical activity (PA) and health-related quality of life (HRQOL) relationship. However, less is known about this association when advanced measurement techniques are used to assess HRQOL. The aim of this study was to use item response theory (IRT) to score HRQOL items and subsequently examine the extent to which PA relates to the new measure. Methods: Data from N = 6,245 adults 18+ years of age participating in the 2019 Montana Behavioral Risk Factor Surveillance System (BRFSS) were used. Four different 3-category HRQOL items were created from survey questions regarding general, physical, mental, and activity health. Two PA variables were created from survey questions regarding PA guidelines and PA quantity. A graded response IRT model (GRM) was used to assess the HRQOL scale and output ability scores. Multinomial logistic regression was used to examine the relationship between PA and HRQOL tertile membership while adjusting for sex, age, race, income, education, marital status, BMI, smoking status, and alcohol consumption. Results: Factor analysis retained a single HRQOL factor (loadings > .68) with ordinal alpha indicating acceptable internal consistency (α_ordinal = .83). The GRM analysis confirmed all HRQOL items fit a unidimensional construct with adequate discrimination (as: 1.17 to 5.13) and difficulty (bs: -2.052 to -0.07). Fully adjusted regression models showed increased odds of high HRQOL tertile membership (versus low tertile) for adults meeting aerobic PA (APA) (OR = 1.64, 95% CI: 1.28 – 2.09) and adults meeting both APA and muscle strengthening activity (MSA) (OR = 1.73, 95% CI: 1.34 – 2.23) guidelines, compared to those meeting neither APA nor MSA guidelines. Similarly, there was increased odds of high HRQOL tertile membership (versus low tertile) for adults considered sufficiently active (OR = 1.59, 95% CI: 1.16 – 2.19) and adults considered highly active (OR = 2.03, 95% CI: 1.58 – 2.61), compared to those considered inactive. Adults meeting MSA guidelines only and adults insufficiently active were no more likely to see high HRQOL tertile membership than their less active counterparts. Conclusion: The IRT-derived HRQOL score is a novel outcome measure and found to be associated with both PA guidelines and PA quantity among adults in Montana.

Keywords:
physical activity (PA) Health-related Quality of Life (HRQOL) item response theory (IRT) graded response model (GRM) rural health

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References:

[1]	Mao Z, Ahmed S, Graham C, Kind P. The unfolding method to explore health-related quality of life constructs in a Chinese general population. Value in Health. 2021 Jun 1; 24(6): 846-54.
[2]	Phyo AZ, Ryan J, Gonzalez-Chica DA, Woods RL, Reid CM, Nelson MR, Murray AM, Gasevic D, Stocks NP, Freak-Poli R. Health-related quality of life and all-cause mortality among older healthy individuals in Australia and the United States: a prospective cohort study. Quality of Life Research. 2021 Apr; 30(4): 1037-48.
[3]	Hart PD. Meeting recommended levels of physical activity and health-related quality of life in rural adults. Journal of lifestyle medicine. 2016 Mar; 6(1): 1.
[4]	Hart PD. Sex differences in the physical inactivity and health-related quality of life relationship among rural adults. Health promotion perspectives. 2016; 6(4): 185.
[5]	Hart PD, Buck DJ. The effect of resistance training on health-related quality of life in older adults: Systematic review and meta-analysis. Health promotion perspectives. 2019; 9(1): 1.
[6]	Baker FB, Kim SH. The basics of item response theory using R. New York: Springer; 2017 Apr 25.
[7]	Centers for Disease Control and Prevention. The BRFSS data user guide. August 15, 2013.
[8]	Centers for Disease Control and Prevention. Behavioral Risk Factor Surveillance System Overview: BRFSS 2019. July 26, 2019.
[9]	Gadermann AM, Guhn M, Zumbo BD. Estimating ordinal reliability for Likert-type and ordinal item response data: A conceptual, empirical, and practical guide. Practical Assessment, Research, and Evaluation. 2012; 17(1): 3.
[10]	SAS Institute Inc. 2015. SAS/STAT® 14.1 User’s Guide. The IRT Procedure. Cary, NC: SAS Institute Inc.
[11]	Zahran HS, Kobau R, Moriarty DG, Zack MM, Holt J, Donehoo R. Health-related quality of life surveillance—United States, 1993-2002. Morbidity and Mortality Weekly Report: Surveillance Summaries. 2005 Oct 28; 54(4): 1-35.