1. A Rasch analysis of the Brief Pain Inventory Interference subscale reveals three dimensions and an age bias 
David M. Walton, Tyler Beattie, Joseph Putos, Joy C. MacDermid 
Journal of Clinical Epidemiology 
Volume 74, Pages (June 2016)
DOI: /j.jclinepi
Copyright © 2016 Elsevier Inc. Terms and Conditions

2. Fig. 1
Category probability curves of the original 0–10 scaling. Only the data from the intake period are shown, and the follow-up data look nearly identical.
Journal of Clinical Epidemiology  , DOI: ( /j.jclinepi )
Copyright © 2016 Elsevier Inc. Terms and Conditions

3. Fig. 2
Category probability curves after rescaling. In this scale, 0 = 0, 1 = 1 + 2 + 3, 2 = 4 + 5, 3 = 6 + 7, 4 = 8, 5 = 9, and 6 = 10.
Journal of Clinical Epidemiology  , DOI: ( /j.jclinepi )
Copyright © 2016 Elsevier Inc. Terms and Conditions

4. Fig. 3
Person-item threshold distribution histograms of the three domain (physical, affective, and sleep) interference subscale for younger subjects (top) and older subjects (bottom). SD, standard deviation.
Journal of Clinical Epidemiology  , DOI: ( /j.jclinepi )
Copyright © 2016 Elsevier Inc. Terms and Conditions