Abstract ID: 3603

Primary Topic: Patient-Centered Outcomes Research
Secondary Topic: State of the science/evidence base for integrative modalities
Tertiary Topic: Mind-body (including meditation and yoga)

Pain and Functional Trajectories in Symptomatic Knee Osteoarthritis over a 12-week Period of Non-Pharmacological Exercise Interventions
Augustine C Lee, MD; William F Harvey, MD, MSc; Xingyi Han, MPH, Tufts Medical Center, Boston, MA, United States; Lori L Price, MAS, MLA, Tufts University, Boston, MA, United States; Jeffrey B Driban, PhD, ATC, CSCS; Raveendhara R Bannuru, MD, PhD; Chenchen Wang, MD, MSc, Tufts Medical Center, Boston, MA, United States

Late Breaker: No

Purpose

While exercise is the recommended treatment for knee osteoarthritis (OA), heterogeneous patterns in treatment response are poorly understood. We aim to identify pain and functional trajectories from exercise interventions among adults with symptomatic knee OA and explore their association with baseline participant factors.

Methods/Session Format

Secondary analysis of a single-blind randomized trial comparing 12-week Tai Chi and Physical Therapy programs in adults with symptomatic knee OA (ACR Criteria). We used weekly measures of WOMAC pain (0-500) and function (0-1700) to identify trajectories using group-based trajectory models. Time was measured in attendance-weeks, defined as the number of weeks participants attended their assigned intervention. Associations between baseline participant factors and trajectories were examined using multinomial logistic regression.

Results

We examined 171 participants (mean age 61 years, BMI 32kg/m2, 71% female, 57% white), and identified four pain trajectories: Lower-Early Improvement (43%), Moderate-Early Improvement (32%), Higher-Delayed Improvement (15%), and Higher-No Improvement (10%) (Figure). We found similar trajectories for function, except the lower function trajectories diverged into gradual (12%) or delayed improvement (15%). Compared with the Lower-Early Improvement pain trajectory, moderate and higher pain trajectories were significantly associated with younger age, obesity, black race, and poorer physical and psychological health (Table). A similar pattern of significant associations were found among the functional trajectories (data not shown).

Table. Associations Between Pain Trajectories and Baseline Participant Factors

 

Characteristic

Lower Pain, Early Improvement

n= 74

Odds Ratio (95% CI)

Moderate Pain, Early Improvement

n= 55

Odds Ratio (95% CI)

Higher Pain, Delayed Improvement

n= 26

Odds Ratio (95% CI)

Higher Pain, No Improvement

n= 16

Odds Ratio (95% CI)

Overall p value

Age, years                            

Reference

0.98 (0.94, 1.01)

0.95 (0.90, 0.99)

0.95 (0.90, 1.00)

0.06

Female Sex

Reference

1.10 (0.51, 2.36)

1.50 (0.53, 4.24)

1.35 (0.39, 4.65)

0.87

Black (vs. White and Others)

Reference

2.48 (1.09, 5.61)

4.02 (1.52, 10.68)

7.82 (2.41, 25.35)

0.002

Body Mass Index, kg/m2,  >30 (vs. ≤ 30)

Reference

2.78 (1.33, 5.78)

3.93 (1.41, 10.98)

1.24 (0.42, 3.67)

0.009

Duration of knee pain, years

Reference

0.97 (0.93, 1.01)

1.01 (0.98, 1.05)

0.91 (0.81, 1.03)

0.20

Highest Level of Education

     

Some College or more (vs. High school Graduate or Less)

Reference

0.62 (0.23, 1.66)

1.06 (0.26, 4.26)

0.23 (0.07, 0.79)

0.11

Intervention assignment

     

Tai Chi (vs. Physical Therapy)

Reference

1.67 (0.83, 3.39)

1.78 (0.72, 4.44)

1.43 (0.48, 4.25)

0.43

Physical Health

     

WOMAC Physical Function

(Range: 0-1700)

Reference

1.49 (1.28, 1.73)

2.06 (1.65, 2.57)

2.18 (1.69, 2.82)

<0.0001

Patient Global Assessment

(Range: 0.0-10.0cm)

Reference

1.41 (1.17, 1.70)

2.33 (1.71, 3.19)

1.71 (1.27, 2.31)

<0.0001

SF-36 Physical Component Summary, 

(Range: 0-100)#

Reference

2.16 (1.06, 4.39)

18.61 (4.09, 84.75)

4.66 (1.37, 15.83)

0.0002

PROMIS Sleep Disturbance Short Form, v.8a (Range; T-score: 28.9-76.5)

Reference

0.97 (0.66, 1.41)

2.52 (1.45, 4.39)

2.33 (1.22, 4.45)

0.001

SF-36 Energy and Vitality,(Range: 0-100)#

Reference

0.81 (0.66, 0.99)

0.63 (0.49, 0.82)

0.62 (0.46, 0.84)

0.001

CHAMPS Physical Activity, mod-high calories/week#

Reference

1.70 (0.83, 3.5)

1.74 (0.67, 4.53)

3.35 (0.99, 11.39)

0.17

6-Minute Walk Test, meters

(Normal Range: 400-700)*# 

Reference

0.76 (0.61, 0.95)

0.63 (0.46, 0.84)

0.64 (0.45, 0.89)

0.004

Leg Extensor Muscle Strength**, newtons#; 1RM

Reference

0.92 (0.84, 1.01)

0.91 (0.80, 1.04)

0.89 (0.76, 1.04)

0.20

Muscle Contraction Velocity** meters/second (40% of 1RM)#

Reference

0.96 (0.78, 1.18)

0.69 (0.51, 0.92)

0.70 (0.50, 0.98)

0.03

Berg Balance, ≤50 points (vs. >50 points) (Range: 0-56)#        

Reference

2.19 (0.89, 5.38)

4.27 (1.51, 12.09)

2.13 (0.57, 7.93)

0.05

Psychosocial Health

     

SF-36 Mental Component Summary

(Range: 0-100)#

Reference

0.81 (0.54, 1.20)

0.57 (0.36, 0.92)

0.62 (0.35, 1.10)

0.10

SF-36 Mental Health; (Range: 0-100)#

Reference

0.88 (0.70, 1.11)

0.77 (0.58, 1.01)

0.71 (0.52, 0.97)

0.10

Beck-II Depression, (Range: 0-63)

Reference

1.03 (0.98, 1.08)

1.06 (1.004, 1.12)

1.07 (1.01, 1.13)

0.08

Perceived Stress; (Range: 0-40)           

Reference

0.99 (0.94, 1.05)

1.06 (0.99, 1.13)

1.12 (1.03, 1.22)

0.02

MOS Social Support; (Range: 19-95)#         

Reference

1.00 (0.99, 1.02)

0.99 (0.98, 1.01)

1.01 (0.98, 1.04)

0.75

Arthritis Self-Efficacy Scale-8

(Range: 0-10)#

Reference

0.80 (0.67, 0.96)

0.66 (0.52, 0.84)

0.53 (0.39, 0.72)

<0.0001

Outcome Expectations; (Range: 1.0-5.0)#            

Reference

0.93 (0.49, 1.73)

0.85 (0.38, 1.89)

0.79 (0.30, 2.06)

0.95

1RM= one-repetition maximum; CHAMPS= Community Healthy Activities Model Program for Seniors; CI= Confidence Interval; MOS= Medical Outcomes Survey; PROMIS= Patient-Reported Outcomes Measurement Information Systems; SF-36= Short Form-36; WOMAC= Western Ontario and McMasters Osteoarthritis Index. *Normal range reported for the general population. **For muscle strength, and velocity, total n= 165 to 168. #Higher score indicates greater health. Note: Odds ratios >1.00 favor the first category in dichotomized comparisons. Bold text indicates statistical significance, p ≤ 0.05. 

 

Conclusions

We found four distinct trajectories for pain and function over 12-week exercise interventions among adults with symptomatic knee OA. While most participants experienced early improvements, subgroups with greater baseline pain/physical disability had either gradual, delayed, or no improvements. These findings help disentangle the heterogeneity of treatment response and may advance patient-centered care for these patients.