Hays, R. D., Spritzer, K. L., Amtmann, D., Lai, J-S., DeWitt, E. M.,
Rothrock, N., DeWalt, D. A., Riley, W. T., Fries, J. F., & Krishnan,
E.(2013, epub).Upper extremity and mobility subdomains from
the Patient-Reported Outcomes Measurement Information System (PROMIS®) adult
physical functioning item bank. Archives of Physical Medicine and
Rehabilitation.
Arch Phys Med Rehabil. 2013 Jun 7. pii: S0003-9993(13)00424-3. doi: 10.1016/j.apmr.2013.05.014. [Epub ahead of print]
Upper Extremity and Mobility Subdomains from the Patient-Reported Outcomes Measurement Information System (PROMIS®) Adult Physical Functioning Item Bank.
UCLA Division of General Internal Medicine & Health Services Research, Department of Medicine. 911 Broxton Avenue, Los Angeles, CA 90095-1736; RAND, 1776 Main Street, Santa Monica, CA 90407. Electronic address: drhays@ucla.edu.
Abstract
OBJECTIVE:
To create upper extremity and mobility subdomain scores from the Patient-Reported Outcomes Measurement Information System (PROMIS®) physical functioning adult item bank.
DESIGN:
Expert reviews were used to identify upper extremity and mobility items from the PROMIS item bank. Psychometric analyses were conducted to assess empirical support for scoring upper extremity and mobility subdomains.
SETTING:
Data were collected from the U.S. general population and multiple disease groups via self-administered surveys.
PARTICIPANTS:
The sample included 21,133 English-language adults who participated in the PROMIS wave 1 data collection and 640 Spanish-speaking Latino adults recruited separately.
INTERVENTIONS:
Not Applicable.
MAIN OUTCOME MEASURES:
We use English- and Spanish-language data and existing PROMIS item parameters for the physical functioning item bank to estimate upper extremity and mobility scores. In addition, we fit graded response models to calibrate the upper extremity items and mobility items separately, compare separate to combined calibrations, and produce subdomain scores.
RESULTS:
After eliminating items due to local dependency, 16 items remained to assess upper extremity and 17 items to assess mobility. The estimated correlation between upper extremity and mobility was 0.59 using existing PROMIS physical functioning item parameters (r = 0.60 using parameters calibrated separately for upper extremity and mobility items).
CONCLUSIONS:
Upper extremity and mobility subdomains shared about 35% of variance in common, and produced comparable scores whether calibrated separately or together. The identification of the subset of items tapping these two aspects of physical functioning and scored using the existing PROMIS parameters provides the option of scoring these subdomains in addition to the overall physical functioning score
Fayers, P. M., & Hays, R. D. (2013, May 31 published online first). Don't middle your MIDs: Regression to the mean shrinks estimates of minimally important differences. Quality of Life Research.
Abstract
Minimal important differences (MIDs) for patient-reported outcomes (PROs) are often estimated by selecting a clinical variable to serve as an anchor. Then, differences in the clinical anchor regarded as clinically meaningful or important can be used to estimate the corresponding value of the PRO. Although these MID values are sometimes estimated by regression techniques, we show this this is a biased procedure and should not be used; alternative methods are proposed. http://link.springer.com/article/10.1007%2Fs11136-013-0443-4
