Session Information
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose:
Developed in
general population, rheumatoid arthritis and osteoarthritis patients, the Improved
Health Assessment Questionnaire (iHAQ, formerly PROMIS HAQ) assesses physical
function. The objective of this study was to evaluate the content validity of the
iHAQ in patients with knee OA.
Methods:
In a cross-sectional
analysis using the baseline data from a Tai
Chi versus physical therapy for knee osteoarthritis trial, persons meeting ACR criteria for
knee OA patients self-administered the Improved HAQ, Patient Global Health Visual
Analog Scale (Global VAS score range 0-10, 10=poor health), SF-36 survey (range
0-100, 100=good health), and WOMAC (range 0-1700, 1700=worst). We calculated two
iHAQ scores having the same score range (0-100, 100=poor function) but based on
the 20 items (method A) or 16 items (method B). To evaluate content validity, the
iHAQ was compared with Global VAS, SF-36 Physical Function and Mental Health
Component (PCS and MCS), and WOMAC pain and function using Spearman’s rank
correlation coefficients (rho). ANOVA with Bonferroni adjustment was used to test
the differences in the iHAQ scores across the tertiles of WOMAC function score.
Results:
In 204 knee OA
patients (70% female and 53% white), the mean age was 60.2 years. The median (Interquartile
Range, IQR) of iHAQ scores by the 20-item A and 16-item B methods were 21.9 (9.4,
34.4) and 18.8 (9.4, 31.3), respectively. Table 1 summarizes iHAQ scores
compared with SF-36 PCS and MCS, WOMAC pain and function, and Global VAS scores.
Both iHAQ methods A and B were significantly correlated with other measures,
with method B being slightly better. For physical function, higher iHAQ (poorer
function) was more strongly correlated with lower SF-36 PCS scores (method A: rho=-0.66, p<.0001,
method B: rho=-0.68, p<.0001)
than with higher WOMAC function score (method A: rho=0.34, p<.0001,
method B: rho=0.43, p<.0001).
The iHAQ scores also corresponded to different levels of physical function as
measured by WOMAC function (Figure 1). Higher iHAQ scores were however
only weakly correlated with higher WOMAC pain scores (method A: rho=0.26, p=.0002, method B: rho=0.295, p<.0001), lower SF-36 MCS scores
(method A: rho=-0.36, p<.0001, method B: rho=-0.37, p<.0001), and higher Global VAS scores (method
A: rho=0.28,
p<.0001, method B: rho=0.31, p<.0001).
Conclusion: The
Improved HAQ has content validity for assessing physical function in knee OA
patients. It also correlated more modestly with pain, mental health and global health
status. Investigation for its longitudinal validity (responsiveness) is
warranted.
|
Table 1. Results of Spearman’s Rank Correlation Coefficients Analysis |
|||||
|
Instruments |
Median (IQR) |
Method A |
Method B |
||
|
|
|
rho |
P value |
rho |
P value |
|
Improved HAQ method A (0 best – 100 worst) |
21.9 (9.4, 34.4) |
1.0000 |
– |
0.9756 |
<0.0001 |
|
Improved HAQ method B (0 best – 100 worst) |
18.8 (9.4, 31.3) |
0.9756 |
<0.0001 |
1.0000 |
– |
|
SF-36 PCS (0 worst – 100 best) |
36.7 (29.1, 43.5) |
-0.658 |
<0.0001 |
-0.675 |
<0.0001 |
|
SF-36 MCS (0 worst – 100 best) |
54.6 (46.5, 59.7) |
-0.355 |
<0.0001 |
-0.372 |
<0.0001 |
|
WOMAC Pain (0 best – 500 worst) |
239.8 (172.5, 325.3) |
0.263 |
0.0002 |
0.295 |
<0.0001 |
|
WOMAC Function (0 best – 1700 worst) |
905.8 (623.0, 1147.3) |
0.340 |
<0.0001 |
0.429 |
<0.0001 |
|
Global VAS (0 good – 10 poor) |
5.5 (4.7, 6.0) |
0.284 |
<0.0001 |
0.306 |
<0.0001 |
To cite this abstract in AMA style:
Chung M, Liu S, Fu Z, Price LL, Wong JB, Wang C. Content Validity of the Improved Health Assessment Questionnaire in Knee Osteoarthritis Patients [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/content-validity-of-the-improved-health-assessment-questionnaire-in-knee-osteoarthritis-patients/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/content-validity-of-the-improved-health-assessment-questionnaire-in-knee-osteoarthritis-patients/