Psychometric Issues

Item Response Theory & Psychometric Issues

PDFs and psychometric issue materials are available in our Box folder. Please contact Dr. Hays at drhays@ucla.edu with any questions or concerns about access. 

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2022

Patient Experience Surveys Are Not Harming Patients or Physicians. Ron D. Hays, Marc N. Elliott, Paul D. Cleary. (PDF)

2021

March

Poor Scientific Quality of Bido et. al. paper in Journal of Shoulder and Elbow Surgery.

December

Cut-Points for Global Physical and Global Mental

  • To learn more, see table in Box.

  • The cut points or thresholds for PROMIS Global Physical and Mental score categories of excellent, very good, good, fair, and poor were constructed by 1) creating groups based upon responses to Global01 "In general, would you say your health is excellent, very good, good, fair, or poor?", 2) calculating mean scores for each group, and 3) identifying the midpoint between two adjacent means.  For example, the mean Global Mental score for "Excellent" was 60 and the mean score for "Very Good" was 54.  The midpoint between these scores is 57.
     

    Cut points are:

  • Global Physical: 57-51-43-36
  • Global Mental: 57-51-45-40
  • See here for Gender and Age Subgroup Norms Centered on the US 2000 Census.

March 2022

  • Update with addition of T-scores for PROMIS Global Mental score categories based upon Global02 "overall quality of life"
  • See table in Box.

2020

August

  • The PROMIS Convention for recoding the 0-10 global pain item into five categories based on the grouping of the 0-10 response scales for the Sheehan Disability Scale and the Flushing Questionnaire.
  • See Box files for more details.

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2019

December

  • How did this paper get published in Quality of Life Research?
     

  • Olson, B, Vincent, W., Meyer, J. P., Kershaw, T., Sikkema, K. J., Heckman, T. G., & Hansen, N. B. (2019).  Depressive symptoms, physical symptoms, and health-related quality of life among older adults with HIV. Quality of Life Research, 28, 3313-3322.
  • See PDF in Box: Depressive symptoms are indicators of health-related quality of life.pdf.
     

September 

  • Linear transformation to 0-100 possible range and back

  • -See 0-100 range scoring in Box

April

  • Ron Hays: "PROMIS: The NIH Patient-Reported Outcomes Measurement System." See PDF in Box.
  • Based on a presentation at Retina International's November 2016 Interdisciplinary Workshop addressing the topic "Functional Vision versus Visual Function - Working towards integrating the Patient Perspective."

2018

  • In what sense does IRT yield interval-level measurement?
  • Reise and Haviland (2005, Journal of Personality Assessment, 84(3) note that:
    "There is a linear relation between trait levels and the log odds of endorsing an item.  It is in this sense that the IRT metric provides an interval interpretation.
    Equal changes on the latent trait result in equal changes in the log odds of item endorsement regardless of the level of the latent trait" (p.235).

2017

  • Hays, Ron D.Spritzer, Karen L. (September 18, 2017 - updated).
  • "Estimating theta using existing item parameters with flexMIRT® software."
  • Find PDF in Box. 

2016

  • Estimating reliability from CAT
  • Please find in BOX above.

2014

December

  • SAS® PROC IRT Example.
  • Please find in BOX
    (promisgph.pdf results)
  • Item Response Theory: "What It Is and How You Can Use the IRT Procedure to Apply It," Xinming An and Yiu-Fai Yung, SAS Institute, Paper SAS364-2014

March
 

  • Hochberg, Y. (1988). "A sharper Bonferroni procedure for multiple tests of significance." Biometrika, 75, 800-802. See Box for file.
  • Background on computations: hochberg.doc
  • Please find SAS codes in Box to compute hochberg adjustment:
    • example 1: hochberg.sas, hochberg.lst
    • example 2: hochberg2.sas, hochberg.lst
  • STATA has a module that can implement hochberg adjustment (install multproc):
    • example 1: hochberg.log
    • example 2: hochberg2.log

2013

Find more information about Cohen's rule of thumb for correlations that correspond to effect size rules of 0.20 SD, 0.50 SD and 0.80 SD.

2011

Linear transformation of item parameters (using, e.g., Stocking-Lord transformation constants):

Transformed slope = Slope/Slope transformation constant

Transformed thresholds are: (Threshold * Slope transformation constant) + Intercept

2010

Information Reliability SE

  • See more in Box above.

2009

July

Reeve et al. (2007) in Medical Care provided the following guidelines for good fit to a one-factor model (for evaluation of unidimensionality assumption).

June

Please see Box for publications and tools noted below.

  • Summary of steps to produce raw score conversion to theta estimates for PROMIS global mental health items (6/22/2009) - Karen Spritzer with assistance from Ron D. Hays
  • Summary of steps to produce raw score conversion to theta estimates for PROMIS global physical health items (6/19/2009)  - Karen Spritzer with assistance from Ron D. Hays
    The authors are eternally grateful to Seung Choi for his expertise and guidance.
  • Learn about PPV (positive predictive value) and NPV (negative predictive value) in the Box folder above.
  • Learn more about Rasch Model infit and outfit mean square statistics
  • The infit statistic provides information about responses within a patient’s ability level.The outfit statistic assesses items that are far beyond a person’s ability level. Poor item fit has been defined as infit or outfit < 0.6 or > 1.4.

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