Archives of Physical Medicine and Rehabilitation
December 2017Volume 98, Issue 12, Pages 2485–2490
Daniel Pinto, PT, PhD
Abstract
Objective
To investigate the relationship between sedentary behavior and quality-adjusted life years (QALYs) among participants in the Osteoarthritis Initiative.
Design
Longitudinal, observational design.
Setting
Osteoarthritis Initiative cohort.
Participants
Individuals (N=1794) from a prospective, multicenter longitudinal cohort were classified into quantile groups based on average daily sedentary time (most sedentary, quartile 1 [Q1] ≥11.6h; 10.7h≤ Q2 <11.6h; 9.7h≤ Q3 <10.7h; least sedentary, Q4 <9.7h).
Interventions
Not applicable.
Main Outcome Measures
Individual QALYs were estimated over 2 years from the area under the curve of health-related utility scores derived from the Medical Outcomes Study 12-Item Short-Form Health Survey versus time. The relationship between baseline sedentary behavior and median 2-year QALYs was estimated using quantile regression adjusted for socioeconomic factors and body mass index.
Results
Lower QALYs over 2 years were more frequently found among the most sedentary (Q1, median 1.59), and QALYs increased as time spent in baseline sedentary behavior decreased (median QALYs for Q2, 1.64; Q3, 1.65; Q4, 1.65). The relationship of sedentary time and median QALY change was only significant for the most sedentary Q1 group, where an additional hour of sedentary behavior significantly reduced QALYs by −.072 (95% confidence interval, −.121 to −.020).
Conclusions
Our findings suggest that individuals with the most extreme sedentary profiles may be vulnerable to additional losses of quality of life if they become more sedentary. Targeting these individuals to decrease sedentary behavior has the potential to be cost-effective.