Psychometric Issues

Item Response Theory & Psychometric Issues

PDFs and psychometric issue materials are available in our Box folder via Mednet access only. Please contact Dr. Ron Hays at drhays@ucla.edu with any questions or trouble accessing box folder.

Visit Box for Psychometric Resources

2022

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

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 the table in the 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 the table in the 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 the recoding of global07r in ph4-summary-061909.pdf in the Box files for more detailsdetail.

Visit Box for Psychometric Materials2019

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: 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

  • "PROMIS: The NIH Patient-Reported Outcomes Measurement System."
  • See: Retina International's November 2016 Interdisciplinary Workshop.pdf.

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).
  • See: pattern_scoring_example.pdf. 

2016

  • Estimating reliability from CAT
  • See: estimating_reliability_from_cat.pdf

2014

December

  • SAS® PROC IRT Example.
  • See: 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.
  • See: SAS364-2014.pdf

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 the Box.

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
  • See: mh4-summary-062209.pdf
  • 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.
  • See: ph4-summary-061909.pdf
  • Learn about PPV (positive predictive value) and NPV (negative predictive value) in the Box folder above.
  • 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.