Additional Properties of PROMIS Short Forms

Supplementary Text

METHOD

Procedure

Patients completed a battery of questionnaires before and after the 12-week intervention. The instruments were completed in the following order: Patient Global Assessment of Disease, WOMAC, SF-36, Perceived Stress Scale, Beck Depression Inventory, PROMIS Pain Interference, Physical Function, Depression, and Anxiety. All of the PRO instruments were collected and managed using both paper forms and REDCap™ electronic data capture tools hosted at Tufts Medical Center. The two physical performance tests were administered either prior to or after completion of the questionnaire instruments depending on the availability of research staff.

Additional properties of PROMIS Short Forms

PROMIS instruments were developed through multi-site collaboration using a rigorous, well-documented Instrument Maturity Model involving item pool development, calibration, and preliminary testing.2 Each item ranges from 1-5. Raw score for each PROMIS measure is the sum of all individual items.

The Pain Interference Short Form 6b contains 6 items.1 The Physical Function Short Form 10a contains 10 items.1 The Anxiety Short Form 7a contains 7 items.10 The Depression Short Form 8b contains 8 items.10

Additional properties of Legacy instruments

The SF-36 has over 50 publications in OA specifically.6 It was designed as a universally-relevant, Classical Test Theory (CTT)-based PRO measurement.

The SF-Physical Function measures the ability to perform physical activities without limitations due to health. The subscale score contains 10 items with a 3-point Likert-type scale. The total raw score ranges from 10 to 30. The SF-Social Function measures the ability to perform normal social activities without interference due to physical or emotional problems. The subscale score contains 2 items with a 5-point Likert-type scale. The total raw score ranges from 2 to 10. The SF-Vitality measures the typical amount of energy an individual perceives to have. The subscale score contains 4 items with a 6-point Likert-type. The total raw score ranges from 4 to 24. The SF-Bodily Pain measures a confluence of both pain intensity and pain interference with daily activities. The subscale score contains 2 items with a 5- and 6- point Likert-type scale, respectively. The total raw score ranges from 2 to 12. The SF-Mental Health measures an individual’s emotions, disposition, and affect. The subscale score contains 5 items with a 6-point Likert-type scale. The total raw score ranges from 5 to 30. The SF-Role Physical measures the degree of difficulty to perform normal occupational and personal activities due to physical health. The subscale score contains 4 items with a 2-point Likert-type scale. The total raw score ranges from 4 to 8. The SF-Role Emotional measures the degree of difficulty to perform normal occupational and personal activities due to emotional health. The subscale score contains 3 items with a 2-point Likert-type scale. The total raw score ranges from 3 to 6. The SF-General Health measures an individual’s global evaluation of health. The subscale score contains 3 items with a 5-point Likert-type scale. The total raw score ranges from 5 to 25.14

The WOMAC Index version 3.1 is a CTT-based health status assessment. Its subscales specifically measure pain intensity during physical activity and difficulty with physical functioning. The WOMAC’s psychometric properties have been extensively assessed among individuals with OA, and its use is recommended for clinical trials of adults with OA by several scientific organizations.9 The WOMAC uses a disease-attributed context wherein all symptoms are questioned specifically in relation to OA. The pain subscale’s total score ranges from 0-500mm. The physical function subscale’s total score ranges from 0-1700mm.

The Beck Depression Inventory, second edition, is a CTT-based universally-relevant PRO measurement. Beck Depression is one of the most popular instruments of depressive symptoms in clinical research worldwide.13

The Perceived Stress Scale is a CTT-based, universally-relevant PROthat measures the degree to which individuals believe their life has been unpredictable, uncontrollable, and overloaded during the previous month.7 A systematic review of its psychometric properties supported its construct validity according to moderate to strong correlations with hypothesized psychological variables, including the Hospital Anxiety and Depression Scale, State-Trait Anxiety Inventory, and the Depression Anxiety Stress Scale-217.

The Patient Global Assessment is a CTT-based, disease-attributed questionnaire, which is reflected in the verbiage of its single item, “Considering all the ways your knee OA affects you, how are you doing today?”4,12 The Patient Global is a recommended PRO measure for use in clinical trials of OA by several scientific organizations.5

The Six Minute Walk Testis a patient performance outcome typically performed in a clinical or research setting. This performance test is used to assess submaximal exercise capacity. Participants are asked to walk as far as possible within a six-minute period, results are recorded as distance traveled, and greater distances indicate higher capacity. It has been used to detect changes following interventions to improve exercise tolerance for knee OA patients.3

The 20-Meter Walk Test is frequently used in individuals with OA, and measures gait speed8 in seconds, over a 20 meter distance. Longer times indicate slower gait speed. Both walking tests were performed in quiet hallways and were administered by trained investigators following a standard script.

Handling of missing items

In accordance with instructions from PROMIS scoring manuals, individual PROMIS scores missing no more than 50% of the items were included and missing items were imputed as: (Raw sum x number of items on the form)/(number of items answered).11

RESULTS

Descriptive statistics and floor/ceiling effects for legacy instruments

As expected all legacy instruments reflected improved health outcomes after intervention (Supplementary Table 4). As found in the PROMIS instruments, change in physical outcomes was larger than change in psychological outcomes. SF-36 Role Physical and Role Emotional subscales had significant floor and ceiling effects at both baseline and 12 weeks (33-65%), and SF-36 Social Functioning had significant ceiling effects at baseline and 12 weeks (35-44%). Significant ceiling effects were found in Beck Depression at 12 weeks (21%) and near-ceiling effects at baseline (14%).

Distribution-based MIDS

Absolute values for T-scores corresponding to a Standardized Response Mean (SRM) of 0.2 to 0.5 were PROMIS Depression= 2.1 to 3.5; Anxiety= 2.2 to 3.7; Physical Function= 2.1 to 3.5; and Pain Interference= 1.6 to 4.1. Absolute values for T-scores corresponding to a Cohen’s d of 0.2 to 0.5 were PROMIS Depression= 1.8 to 4.4; Anxiety= 1.8 to 4.5; Physical Function= 1.1 to 2.8; and Pain Interference= 1.4 to 3.6.

Missing data

For PROMIS Depression, 3 people had measurements missing 1 item each at baseline, and 1 person had a measurement missing 1 item at 12 weeks. For PROMIS Anxiety, 1 person had a measurement missing 2 items each at baseline. For PROMIS Physical Function, 1 person had a measurement missing 1 item at 12 weeks. For PROMIS Pain Interference, 1 person had a measurement missing 1 item at 12 weeks. In each case missing items were imputed and the total scores were included in the study participant sample.

Supplementary References

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2. Cella D, Riley W, Stone A, Rothrock N, Reeve B, Yount S, Amtmann D, Bode R, Buysse D, Choi S, Cook K, Devellis R, DeWalt D, Fries JF, Gershon R, Hahn EA, Lai J, Pilkonis P, Revicki D, Rose M, Weinfurt K, Hays R: Initial Adult Health Item Banks and First Wave Testing of the Patient-Reported Outcomes Measurement Information System (PROMIS) Network: 2005-2008. J Clin Epidemiol 63:1179–94, 2011.

3. Focht BC, Rejeski WJ, Ambrosius WT, Katula JA, Messier SP: Exercise, self-efficacy, and mobility performance in overweight and obese older adults with knee osteoarthritis. Arthritis Care Res [Internet] 53:659–65, 2005 [cited 2016 Feb 9]. Available from:

4. Khan NA, Spencer HJ, Abda EA, Alten R, Pohl C, Ancuta C, Cazzato M, Géher P, Gossec L, Henrohn D, Hetland ML, Inanc N, Jacobs JW, Kerzberg E, Majdan M, Oyoo O, Peredo-Wende RA, Selim ZI, Skopouli FN, Sulli A, Hørslev-Petersen K, Taylor PC, Sokka T: Patient’s global assessment of disease activity and patient’s assessment of general health for rheumatoid arthritis activity assessment: are they equivalent? Ann Rheum Dis [Internet] 71:1942–9, 2012. Available from:

5. Kirwan JR, Fries JF, Hewlett SE, Osborne RH, Newman S, Ciciriello S, van de Laar MA, Dures E, Minnock P, Heiberg T, Sanderson TC, Flurey CA, Leong AL, Montie P, Richards PAM: Patient perspective workshop: Moving towards OMERACT guidelines for choosing or developing instruments to measure patient-reported outcomes. J Rheumatol [Internet] 38:1711–5, 2011 [cited 2016 Jan 29]. Available from:

6. Laucis NC, Hays RD, Bhattacharyya T: Scoring the SF-36 in Orthopaedics: A Brief Guide. J Bone Joint Surg Am [Internet] The American Orthopedic Association; 97:1628–34, 2015 [cited 2016 Feb 5]. Available from:

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8. Motyl JM, Driban JB, McAdams E, Price LL, McAlindon TE: Test-retest reliability and sensitivity of the 20-meter walk test among patients with knee osteoarthritis. BMC Musculoskelet Disord [Internet] BMC Musculoskeletal Disorders; 14:166, 2013. Available from:

9. Pham T, Der Heijde DVD Van, Lassere M, Altman RD, Anderson JJ, Bellamy N, Hochberg M, Simon L, Strand V, Woodworth T, Dougados M: Outcome variables for osteoarthritis clinical trials: The OMERACT-OARSI set of responder criteria. J Rheumatol 30:1648–54, 2003.

10. Pilkonis PA, Choi SW, Reise SP, Stover AM, Riley WT, Cella D: Item banks for measuring emotional distress from the Patient-Reported Outcomes Measurement Information System (PROMIS®): depression, anxiety, and anger. Assessment [Internet] 18:263–83, 2011 [cited 2016 May 4]. Available from:

11. PROMIS Health Organization PROMIS Cooperative Group.: PROMIS ® Instrument Development and Validation Scientific Standards Version 2.0 (revised May 2013) [Internet]. 2013 [cited 2016 May 7]. Available from:

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13. Wang YP, Gorenstein C: Psychometric properties of the Beck Depression Inventory-II: A comprehensive review. Rev Bras Psiquiatr 35:416–31, 2013.

14. Ware Jr JE, Sherbourne CD: The MOS 36-item short-form health survey (SF-36): I. Conceptual framework and item selection. Med Care Health Institute, Boston, MA 02111.; 30:473–83, 1992.

Additional Supplementary Content

Supplementary Document: PDF copies of PROMIS Depression, Anxiety, Physical Function, and Pain Interference Short Forms