Abstract
Objectives: To replicate previous Rasch analysis (RA) that yielded the 7-item Physical Function Short Form of the Knee Injury and Osteoarthritis Outcome Score (KOOS-PS7) in order to verify the consistency of the item selection process, and to analyze its main psychometric properties in a sample of Italian patients with osteoarthritis (OA). Design: Methodological research on cross-sectional data from a convenience sample. Setting: University hospital. Participants: Outpatients with symptomatic OA of the knee (N=200; women, 73%; mean age, 69.4y). Interventions: Not applicable. Main Outcome Measure: The KOOS-PF22 (22 items comprising the 2 KOOS domains of activities of daily living and sport/recreation). Its dimensionality was investigated using exploratory factor analysis. RA was performed on KOOS-PF22, KOOS-PS7, and an item set (called KOOS-PS12) obtained by removing from KOOS-PF22 all misfitting items. Results: KOOS-PF22 showed a 2-factor structure, with the first one largely prevailing. Ten of its 22 items did not fit the Rasch model, while item dependency was present in 7 item pairs. Five of 7 KOOS-PS7 items and all KOOS-PS12 items showed acceptable fit to the Rasch model. The person separation reliability was.79 for KOOS-PS7 and.90 for KOOS-PS12; Cronbach alpha was.81 for KOOS-PS7 and.92 for KOOS-PS12. Conclusions: RA was not able to replicate the selection process of the items included in KOOS-PS7. KOOS-PS7 reliability levels indicate that the instrument seems more useful for group decisions than for everyday clinical application in single patients. To achieve a short form of KOOS-PF22 valid for a wide spectrum of individuals with knee OA, further psychometric studies are warranted.
| Original language | English |
|---|---|
| Pages (from-to) | 480-487 |
| Number of pages | 8 |
| Journal | Archives of Physical Medicine and Rehabilitation |
| Volume | 94 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Mar 2013 |
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Keywords
- Osteoarthritis knee
- Outcome measures
- Psychometrics
- Rehabilitation
ASJC Scopus subject areas
- Rehabilitation
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Rasch analysis of the 22 knee injury and osteoarthritis outcome score-physical function items in italian patients with knee osteoarthritis. / Franchignoni, Franco; Salaffi, Fausto; Giordano, Andrea; Carotti, Marina; Ciapetti, Alessandro; Ottonello, Marcella.
In: Archives of Physical Medicine and Rehabilitation, Vol. 94, No. 3, 03.2013, p. 480-487.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Rasch analysis of the 22 knee injury and osteoarthritis outcome score-physical function items in italian patients with knee osteoarthritis
AU - Franchignoni, Franco
AU - Salaffi, Fausto
AU - Giordano, Andrea
AU - Carotti, Marina
AU - Ciapetti, Alessandro
AU - Ottonello, Marcella
PY - 2013/3
Y1 - 2013/3
N2 - Objectives: To replicate previous Rasch analysis (RA) that yielded the 7-item Physical Function Short Form of the Knee Injury and Osteoarthritis Outcome Score (KOOS-PS7) in order to verify the consistency of the item selection process, and to analyze its main psychometric properties in a sample of Italian patients with osteoarthritis (OA). Design: Methodological research on cross-sectional data from a convenience sample. Setting: University hospital. Participants: Outpatients with symptomatic OA of the knee (N=200; women, 73%; mean age, 69.4y). Interventions: Not applicable. Main Outcome Measure: The KOOS-PF22 (22 items comprising the 2 KOOS domains of activities of daily living and sport/recreation). Its dimensionality was investigated using exploratory factor analysis. RA was performed on KOOS-PF22, KOOS-PS7, and an item set (called KOOS-PS12) obtained by removing from KOOS-PF22 all misfitting items. Results: KOOS-PF22 showed a 2-factor structure, with the first one largely prevailing. Ten of its 22 items did not fit the Rasch model, while item dependency was present in 7 item pairs. Five of 7 KOOS-PS7 items and all KOOS-PS12 items showed acceptable fit to the Rasch model. The person separation reliability was.79 for KOOS-PS7 and.90 for KOOS-PS12; Cronbach alpha was.81 for KOOS-PS7 and.92 for KOOS-PS12. Conclusions: RA was not able to replicate the selection process of the items included in KOOS-PS7. KOOS-PS7 reliability levels indicate that the instrument seems more useful for group decisions than for everyday clinical application in single patients. To achieve a short form of KOOS-PF22 valid for a wide spectrum of individuals with knee OA, further psychometric studies are warranted.
AB - Objectives: To replicate previous Rasch analysis (RA) that yielded the 7-item Physical Function Short Form of the Knee Injury and Osteoarthritis Outcome Score (KOOS-PS7) in order to verify the consistency of the item selection process, and to analyze its main psychometric properties in a sample of Italian patients with osteoarthritis (OA). Design: Methodological research on cross-sectional data from a convenience sample. Setting: University hospital. Participants: Outpatients with symptomatic OA of the knee (N=200; women, 73%; mean age, 69.4y). Interventions: Not applicable. Main Outcome Measure: The KOOS-PF22 (22 items comprising the 2 KOOS domains of activities of daily living and sport/recreation). Its dimensionality was investigated using exploratory factor analysis. RA was performed on KOOS-PF22, KOOS-PS7, and an item set (called KOOS-PS12) obtained by removing from KOOS-PF22 all misfitting items. Results: KOOS-PF22 showed a 2-factor structure, with the first one largely prevailing. Ten of its 22 items did not fit the Rasch model, while item dependency was present in 7 item pairs. Five of 7 KOOS-PS7 items and all KOOS-PS12 items showed acceptable fit to the Rasch model. The person separation reliability was.79 for KOOS-PS7 and.90 for KOOS-PS12; Cronbach alpha was.81 for KOOS-PS7 and.92 for KOOS-PS12. Conclusions: RA was not able to replicate the selection process of the items included in KOOS-PS7. KOOS-PS7 reliability levels indicate that the instrument seems more useful for group decisions than for everyday clinical application in single patients. To achieve a short form of KOOS-PF22 valid for a wide spectrum of individuals with knee OA, further psychometric studies are warranted.
KW - Osteoarthritis knee
KW - Outcome measures
KW - Psychometrics
KW - Rehabilitation
UR - http://www.scopus.com/inward/record.url?scp=84875368297&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84875368297&partnerID=8YFLogxK
U2 - 10.1016/j.apmr.2012.09.028
DO - 10.1016/j.apmr.2012.09.028
M3 - Article
C2 - 23063879
AN - SCOPUS:84875368297
VL - 94
SP - 480
EP - 487
JO - Archives of Physical Medicine and Rehabilitation
JF - Archives of Physical Medicine and Rehabilitation
SN - 0003-9993
IS - 3
ER -