Risk-stratified Care Improves Pain-related Knowledge and Reduces Psychological Distress for Low Back Pain: A Secondary Analysis of a Randomized Trial.

Background: A number of efforts have been made to tailor behavioral healthcare treatments to the variable needs of patients with low back pain (LBP). The most common approach involves the STarT Back Screening Tool (SBST) to triage the need for psychologically informed care, which explores concerns about pain and addresses unhelpful beliefs, attitudes, and behaviors. Such beliefs that pain always signifies injury or tissue damage and that exercise should be avoided have been implied as psychosocial mediators of chronic pain and can impede recovery. The ability of physical therapy interventions guided by baseline stratification for risk of persistent LBP or related functional limitations to improve unhelpful pain beliefs has not been well assessed. Because treatments are aimed at addressing these beliefs, understanding a bit more about the nature of beliefs about pain (for example, attitudes and knowledge) might help us understand how to better tailor this care or even our risk-stratification approaches for future treatment of patients with LBP.

Questions/purposes: (1) Did patients assigned to receive risk-stratified care score higher on an assessment of pain science knowledge? (2) Did patients assigned to receive risk-stratified care have fewer unhelpful attitudes related to pain? (3) Did patients assigned to receive risk-stratified care have less pain-associated psychological distress? (4) Regardless of intervention received, is baseline SBST risk category (low, medium, or high) associated with changes in attitudes and knowledge about pain?

Methods: This is a secondary analysis of short-term changes in pain beliefs following the 6-week treatment phase of a randomized controlled trial that examined the effectiveness of a risk-stratified physical therapy intervention on pain-related disability at 1 year. Between April 2017 and February 2020, a total of 290 patients in the Military Health System seeking primary care for LBP were enrolled in a trial comparing a behavioral-based intervention to usual care. The intervention involved psychologically informed physical therapy using cognitive behavioral principles and included tailored education, graded exercise, and graded exposure. Individuals assigned to usual care followed treatment plans set forth by their primary care provider. Thirty-one patients were removed from Optimal Screening for Prediction of Referral and Outcome Yellow Flag (OSPRO-YF) tool analyses due to missing assessments at 6 weeks (n = 15 intervention; n = 16 usual care). This resulted in 89% (259 of 290) of participants included for secondary analysis, with no difference in baseline demographic characteristics between groups. The usual-care group comprised 50% of the total study group (129 of 259), with a mean age of 34 ± 9 years; 67% (87 of 129) were men. The risk-stratified care group comprised 50% (130 of 259) of the total study group, with a mean ± SD age of 35 ± 8 years; 64% (83 of 130) were men. Six additional individuals were removed from Survey of Pain Attitudes harm scale (SOPA-h) and revised Neurophysiology of Pain Questionnaire (rNPQ) analyses for missing baseline data (n = 1 intervention) and 6-week data (n = 2 intervention; n = 3 usual care). The rNPQ captured current pain science knowledge, the SOPA-h examined patient attitudes about pain (the extent of beliefs that pain leads to damage and that movement is harmful), and the OSPRO-YF assessed patients for yellow flag clinical markers of pain-related psychological distress across 11 constructs within domains of negative mood, fear avoidance, and positive affect/coping indicative of elevated vulnerability and decreased resilience. Outcomes were assessed at baseline and 6 weeks, and data were analyzed per protocol. We assessed between-group differences at 6 weeks using linear mixed-effects models of pain attitudes and knowledge and related distress, controlling for age, gender, and baseline pain. Regardless of treatment group, we also analyzed differences in rNPQ and SOPA-h scores at 6 weeks based on SBST risk category (low versus medium or high) using generalized linear (Gaussian) regression models.

Results: Risk-stratified treatment was associated with improvements in pain knowledge (rNPQ mean difference 6% [95% confidence interval (CI) 1% to 11%]; p = 0.01) and a reduction in indicators of pain-associated psychological distress (OSPRO-YF mean difference -1 [95% CI -2 to 0]; p = 0.01) at 6 weeks compared with usual care. There was no difference between groups for SOPA-h score at 6 weeks (mean difference -0.2 [95% CI -0.3 to 0.0]; p = 0.09). Patients with medium- or high-risk scores on the SBST, regardless of intervention, improved slightly more on SOPA-h (β = -0.31; p < 0.01) but not rNPQ (β = 0.02; p = 0.95) than those scoring low risk.

Conclusion: Patients receiving risk-stratified care showed small improvements in pain knowledge and reductions in pain-related psychological distress at 6 weeks, immediately after intervention, compared with usual care. Implementation of this risk-stratified care approach for LBP was able to change patients' perceptions about pain and reduce some of their psychological distress beyond what was achieved by usual care in this setting. As these factors are believed to favorably mediate treatment outcomes, future studies should investigate whether these improvements persist over the long term, determine how they influence clinical outcomes, and explore alternatives for risk stratification and treatment to elicit greater improvements.Level of Evidence Level III, therapeutic study.