Table 1. Template for Intervention Description and Replication Recommended Reporting Elements Describing Intervention of the Trial^a.

Item No. and name	Description
1. Brief name	Risk-stratified care for low back pain (based on low-, medium-, and high-risk categories of the STarT Back screening tool)
2. Why	Prior work suggests psychosocial profile at baseline is an indicator of prognosis. Instead of trying to determine a specific diagnosis and targeting treatment to the diagnosis, this approach instead focuses on the prognosis of the patient regardless of what the specific patho-mechanical diagnosis might be. Treatment is then tailored to 1 of 3 different risk categories. Patients at lower risk for poor prognosis usually need less intervention, and patients at higher risk often need more intervention. It is an approach designed to make more efficient use of health care resources by targeting the intensity of care based on perceived need.
3. What materials	Patients fill out a 9-item questionnaire. The score places the individual in 1 of 3 treatment categories based on risk for poor prognosis (low, medium, or high).
4. What procedures	All groups Evidence-based assessment of low back pain according to current clinical practice guidelines, including the limited use of imaging except for patients with red flags Enhanced active management advice emphasizing positive messages about activity, pain relief, and work for lower back pain Reassurance to address specific concerns related to their lower back pain and implications on work A copy of the Back Book and view a 5-minute video based on the Back Book entitled “The Truth About LBP”b Low-risk group The aforementioned items with a 2-item spinal manipulation screening, with spinal manipulation delivered in primary care if indicatedc No referral for ongoing physical therapy Medium-risk group Same as low-risk group with referral for ongoing physical therapy based on the Treatment Based Classification principles for up to 8 visits, 30-60–minute sessions (twice weekly)d High-risk group Same as low- and medium-risk groups, and patient is referred for ongoing physical therapy using Treatment Based Classification principles for up to 12 visits, 45-60–minute sessions (twice weekly)d Physical therapy is psychologically augmented with the assessment of biopsychosocial risk factors and the adoption of cognitive behavioral principles that explore patient concerns and address unhelpful beliefs and behaviors. These strategies include tailored education, graded exercise, graded exposure, among others. Details of the content of the psychologically informed physical therapy are available elsewhere14 and have been used in other trials.9
5. Who provided	Primary care clinicians included physicians, nurse practitioners, and physicians’ assistants. The primary care clinician would initially see the patient, provide education, and refer those they deemed eligible to participate in the study. Once in the study, to ensure a minimum baseline of education for all participants, everyone received the education described in “All groups” from item 4. Licensed and credentialed physical therapists then provided the additional care for all 3 risk groups. These individuals included a variety of backgrounds, years of practice, and expertise levels. The physical therapists delivering the risk-stratified care attended a 2-d course that provided training for the delivery of care to patients in this treatment group (psychologically informed physical therapy, vignettes, case studies, practical application).
6. How	The physical therapists received the risk stratification score from the research team and delivered care in the clinic.
7. Where	Care took place in the primary care/family medicine clinic or physical therapy clinic. Treatment for low-risk care often took place in the primary care clinic, and care for medium- and high-risk groups took place in the outpatient physical therapy clinics.
8. When and how much	The specific number of sessions was not controlled or directed in this study. The risk-stratified care is designed to be minimal visits for low risk (1-2), more visits for medium risk (6-8) and the most visits for the high-risk group (10-12); however, this was left up to the individual physical therapist to determine as they felt most appropriate based on the individual information they had about the patient and training they had received. The longest window of care should have been approximately 6 weeks, with the goal of at least twice a week for patients in medium- and high-risk groups. Actual number of visits in each group is outlined in eTables 2 and 3 in Supplement 2.
9. Tailoring	The treatment was tailored according to the risk category of each individual patient (low, medium, or high) as described previously. Within the same risk category, the amount of care was not controlled within the study and left up to the clinician to determine, keeping in consideration all that they had learned in the training about the needs of patients within each of the 3 risk categories.
10. Modifications	The treatment plan was not modified, but the treatment likely varied somewhat from patient to patient and between clinicians, as they had the freedom to deliver care as they thought best. The study manipulated the training received by the participating physical therapists, asking them to treat their patients within the tenants of risk-stratified care.
11. How well (planned)	There was no plan to assess intervention adherence or fidelity a priori, as the number and exact content of sessions was expected to vary across patients and even some within the same risk category.
12. How well (actual)	Treatment fidelity was tracked at the end of the study using data from electronic medical records stored in the Military Health System Data Repository. This allowed for the calculation of the number of back pain–related physical therapy visits for every participant but not the specific content of each visit. The total number of physical therapy visits could then be a proxy for treatment fidelity (fewest visits for individuals in the low-risk group; most visits for individuals in the high-risk group).

Abbreviation: STarT Back, Subgroups of Targeted Treatment for Back Pain.

^a This table provides details for the risk-stratified care based on guidance from the Template for Intervention Description and Replication checklist. Details of usual care are listed in eTable 6 in Supplement 2 according to current recommendations for reporting and describing usual care treatment groups.

^b Klaber Moffett et al,¹⁵ 2002; Clinically Relevant Technologies, 2018.¹⁶

^c Spinal manipulation described in Fritz et al,¹⁷ 2005.

^d Treatment Based Classification described in Delitto et al,¹⁸ 2012.