'STAR' treatment: Personalized referrals improve chronic pain after total knee replacement
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A personalized referral system dubbed Support and Treatment After Replacement, or STAR, is cost effective and improves chronic pain after total knee replacement over a 1-year period, according to data published in The Lancet Rheumatology.
“One in five people who have knee replacement for osteoarthritis find that they have long-term pain afterwards,” Rachael Gooberman-Hill, PhD, of Southmead Hospital, in Bristol, United Kingdom, told Healio. “We wanted to do something that could help people in this situation. We designed a new care pathway, called STAR. This gave people who had long-term pain after knee replacement the chance to receive assessment and care for their pain.”
To study the clinical and cost effectiveness of the pathway for chronic pain following total knee replacement — defined as new or worse pain at 3 months or longer after surgery — Gooberman-Hill and colleagues conducted an unmasked, parallel group, pragmatic, superiority, randomized controlled trial at eight U.K. National Health Service (NHS) hospitals. Between Sept. 6, 2016, and May 31, 2019, a total of 363 patients with chronic pain after total knee replacement were randomly assigned 2:1 to the STAR pathway alongside usual care or to usual care alone.
Participants who received the STAR intervention underwent assessment from an extended scope practitioner and were referred to existing NHS services targeted at their specific potential causes of pain. This involved one or more referrals to an orthopedic surgeon for pain caused by surgical factors or possible infection; a physiotherapist for muscle strengthening; a pain specialist for treatment of complex regional pain syndrome; a general practitioner for additional assessment, treatment for depression or anxiety, or treatment for neuropathic pain with amitriptyline, gabapentin or pregabalin for 3 months.
For patients with neuropathic pain, those who were intolerant to their first medication received an alternative, followed by recommendations for referral to pain services if needed. If necessary, patients received more than one referral simultaneously for their individual needs. They then participated in a telephone follow-up over 12 months.
Meanwhile, usual care included an 8-week post-surgery follow-up, with some clinicians providing an additional 3-month appointment. Surgical teams followed routine follow-up policies. Usual care did not include routine assessment and follow-up care from pain specialists.
Co-primary outcomes included self-reported pain severity and pain interference in the replaced knee, measured using the Brief Pain Inventory (BPI) severity and interference scales — ranging from zero to 10, best to worst — at 12 months. The researchers analyzed these outcomes on an as-randomized basis. Meanwhile, resource use, collected from electronic hospital records and participants, was valued using U.K. reference costs. The researchers used EQ-5D-5L responses to calculate quality-adjusted life-years.
A total of 313 participants — 213 in the STAR group — provided follow-up data at 12 months after randomization.
According to the researchers, the mean between-group difference in the BPI severity score at 12 months was –0.65 (95% CI, –1.17 to –0.13), while the mean between-group difference in the BPI interference was –0.68 (95% CI, –1.29 to –0.08), both favoring the STAR program. The intervention was cost-effective, showing greater improvement with lower cost, with an incremental net monetary benefit of £1,256 ($1,699) (95% CI, 164-2,348), at £20,000 ($27,000) per QALY threshold. One adverse reaction — participant distress — was reported in the STAR group.
“People who received the care pathway had less pain 1 year later than people who had not received the STAR care pathway,” Gooberman-Hill said. “The study provides an evidence-based way for people to receive care for long-term pain after knee replacement. The next step is to encourage healthcare settings to consider offering the approach.”