Knee osteoarthritis (OA) is one of the most common health problems and a leading cause of disability among veterans. Physical therapy (PT) and ongoing exercise are associated with reduced pain and improved physical function among patients with knee OA, yet the majority of veterans with OA are physically inactive. Furthermore, PT services are a limited resource in the VA health care system, with demand exceeding supply. VA patients with knee OA generally receive only one or two PT visits. Prior research indicates this amount of clinical contact time is not sufficient to provide patients with the assessment, instruction, and support needed to adopt and maintain an exercise program, particularly in the context of a chronic pain condition. Therefore, development, testing, and implementation of mechanisms to cost-effectively expand PT services for knee OA may play a key role in improving pain and other outcomes in this large group of veterans.
The objective of this study was to compare the effectiveness of a group-based PT program for knee OA with usual individual PT care for knee OA.
This study was a randomized controlled trial of a 12-week, group-based PT program among 320 veterans with symptomatic knee OA at the Durham VAMC. Participants were randomly assigned to the group-based PT program or individual PT (usual care). The group PT arm included 6 visits (1 to 1 1/2 hours each, every other week) led by a physical therapist and PT assistant, with 8 participants per group. The individual PT arm, modeled after typical PT care for knee OA at the Durham VAMC, included 2 1-hour visits with a physical therapist, 2-3 weeks apart. The group PT (GPT) sessions included group instruction in joint care (activity pacing and joint protection), group discussion of exercise successes and barriers, group exercise, and scheduled individual consultations with the physical therapist (2 per participant, 15-20 minutes each) to address specific functional and therapeutic needs. While the individual PT (IPT) sessions differed in structure, they included the same informational, assessment, and therapeutic content as the group sessions. Both groups were given instructions for the same home exercise program. The primary outcome for this study was the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC). The secondary outcome was objectively assessed physical function (Short Physical Performance Battery; SPPB). These outcomes were assessed at baseline and 12-week follow-up. The WOMAC was also assessed via telephone at 24-week follow-up to examine whether any observed intervention effects are maintained. Mixed linear models were used to compare outcomes for the two study arms. We will also conduct an economic analysis of the group-based PT program.
Among 716 patients who were screened via telephone regarding study eligibility, n=320 were eligible and agreed to participate (n=290 were ineligible, and n=106 declined or could not be scheduled). Of the 320 enrolled participants, 250 (78.1%) completed 12-week follow-up assessments (GPT=125, IPT=125), and 260 (81.3%) completed 24-week follow-up assessments (GPT=132, IPT=128). The mean age of participants was 60.0 years (standard deviation (SD) = 9.8), 88% were men, and 58% were non-white. The mean duration of arthritis symptoms was 15.3 years (SD = 11.8).
The median numbers of sessions attended for GPT and IPT were 5 (out of 6 possible) and 2 (out of 2 possible), respectively. At 12-week follow-up, WOMAC scores were 2.7 points lower in the GPT group vs. IPT [95% confidence interval (CI) = -5.9, 0.5; p=0.10], indicating no meaningful difference in improvement between arms. However, mean total WOMAC scores declined -4.5 points from baseline across both arms combined [95% CI =-6.8,-2.2; p=0.0001], indicating meaningful improvement. At 12-week follow-up there was also no significant difference between study arms in objective physical function, measured by the SPPB (estimated mean difference = 0.0, 95% CI = -0.4, 0.4, p=0.97). There was also no overall difference in SPPB scores among study participants, possibly due to a ceiling effect on this measure. We also observed overall improvements in exploratory outcomes of six-minute walk time, physical activity, and satisfaction with physical function; there were no significant differences between groups for any of these outcomes. At 24-week follow-up, WOMAC scores across both arms were 3.1 points lower compared to baseline [95% CI = -5.4, -0.7; p=0.01], indicating some sustained improvement in both groups, with no difference between groups (p=0.44).
Results of this study confirm that PT improves pain and functional outcomes in patients with knee OA; this is important because there have been few pragmatic / effectiveness studies of PT for knee OA. Our primary and secondary hypotheses were not supported, as outcomes did not differ substantially between GPT and IPT arms. These results indicate that either approach is an effective means of delivering PT services for knee OA. However, the GPT approach in this study required less overall staff time per patient to deliver, and it could provide services efficiently to larger numbers of patients. Therefore, it should be considered as a viable model for health systems to provide this service to veterans with knee OA, potentially increasing access to this service.
- Allen KD, Lo G, Abbate LM, Floegel TA, Lindquist JH, Coffman C, Oddone EZ, Taylor SS, Hall K. Composite measures of physical activity and pain associate better with functional assessments than pain alone in knee osteoarthritis. Clinical Rheumatology. 2019 Aug 1; 38(8):2241-2247.
- Allen KD, Bongiorni D, Bosworth HB, Coffman CJ, Datta SK, Edelman D, Hall KS, Lindquist JH, Oddone EZ, Hoenig H. Group Versus Individual Physical Therapy for Veterans With Knee Osteoarthritis: Randomized Clinical Trial. Physical Therapy. 2016 May 1; 96(5):597-608.
- Allen KD, Bongiorni D, Walker TA, Bartle J, Bosworth HB, Coffman CJ, Datta SK, Edelman D, Hall KS, Hansen G, Jennings C, Lindquist JH, Oddone EZ, Senick MJ, Sizemore JC, St John J, Hoenig H. Group physical therapy for veterans with knee osteoarthritis: study design and methodology. Contemporary clinical trials. 2013 Mar 1; 34(2):296-304.
- Allen KD, Hall K, Lindquist JH, Taylor SS, Coffman CJ. Is It Important to Adjust for Physical Activity When Measuring Chronic Pain? Poster session presented at: Society of Behavioral Medicine Annual Meeting and Scientific Sessions; 2016 Mar 30; Washington, DC.
- Allen KD, Bongiorni D, Walker TA, Bartle J, Bosworth HB, Coffman CJ, Datta SK, Edelman D, Hall KS, Hansen G, Jennings C, Lindquist J, Oddone EZ, Hoenig H. Randomized clinical trial of group vs. individual physical therapy for knee osteoarthritis. Poster session presented at: American College of Rheumatology / Association of Rheumatology Health Professionals Annual Meeting; 2015 Nov 14; Boston, MA.
- Huffman KM, Coffman CJ, Lindquist J, Hall K, Hoenign HM, Allen KD. Initial Symptoms and Prior Knee Injuries are Indicative of Better Symptom Responses to Physical Therapy for Knee OA. Presented at: Osteoarthritis Research Society International World Congress on Osteoarthritis; 2015 Apr 30; Seattle, WA.
Treatment - Efficacy/Effectiveness Clinical Trial