ACT is a form of cognitive behavioral therapy that is well established for the treatment of chronic pain. The goal of ACT is to build psychological flexibility thereby interrupting pain avoidance behavior patterns. Participants randomized to ACT will take part in 12 sessions over the course of 12 weeks. Sessions will be delivered as a combination of 4 remote face-to-face visits with a therapist and 8 therapist-supported online sessions (self-directed online modules supported by provider coaching). Online sessions will focus on helping participants accept pain, connect with negative thoughts and emotions, develop mindfulness and identify and commit to values and goals that are important to them. During face-to-face sessions with the therapist, participants will be encouraged to share their experience of skills practice and mastery, provide examples of skill use at home, and describe what barriers they encountered.

Duloxetine is a serotonin norepinephrine reuptake inhibitor (SNRI) that is FDA-approved for use in Chronic Low-Back Pain, and, as such, is included as a recommended therapy in nearly all current treatment guidelines for low back pain. Study participants will be treated with duloxetine for 12 weeks during the active treatment phase. At the time of randomization, the approved drug pharmacy at each study site will dispense between 185 and 192 duloxetine 30 mg capsules and provide to participants. This will ensure enough capsules to maintain up to a 60 mg dosage through the 12-week intervention phase and to taper the dose in the 13th week if needed.

Licensed physical therapists (PTs) or Doctors of Chiropractic (DCs) will rely on evidence-based guidance to direct decision-making on the particular type of manual and exercise therapy that may be best suited to an individual study participant. Special attention will be paid to the clinician's choice of language in regard to the purpose and expected outcomes of manual therapy in order to avoid enhancing catastrophizing ideations or preference for passive interventions. A total of 10 sessions will be provided over an 8-week treatment period. Two sessions per week are provided in the first two weeks followed by weekly sessions over the next 6 weeks. Treatment sessions will last approximately 60 minutes each.

The Enhanced Self-Care intervention will be comprised of educational modules on evidence-based cognitive-behavioral self-management skills for pain. These modules will be provided digitally for self-administration over a period of 12 weeks. There will be no therapist associated with the delivery of these educational materials; however, after the first four modules, email or text messages will be used to make personalized recommendations for accessing additional modules based upon identified problems from the baseline assessment. Additionally, the walking program module will utilize Fitbit step tracking to allow participants to monitor their walking progress.

Total of all reporting groups

The PEG scale, a subset of the Brief Pain Inventory (BPI), evaluates pain intensity and its impact on enjoyment of life and general activity (i.e., pain interference) using a ranked scale (score 0 = "No Pain" or "Does not Interfere" to 10 = "Pain as bad as you can imagine" or "Completely Interferes"). Each component (Pain, Enjoyment of Life, and General Activity) is on a 0-10 scale, with an average score taken of the three, and with a higher average score reflecting greater disruption in daily functioning.

The PEG scale, a subset of the Brief Pain Inventory (BPI), evaluates pain intensity and its impact on enjoyment of life and general activity (i.e., pain interference) using a ranked scale (score 0 = "No Pain" or "Does not Interfere" to 10 = "Pain as bad as you can imagine" or "Completely Interferes"). Each component (Pain, Enjoyment of Life, and General Activity) is on a 0-10 scale, with an average score taken of the three, and with a higher average score reflecting greater disruption in daily functioning.

Low-Back Pain Specific Pain Intensity measures pain intensity using a single, 10-point ranked scale (score 0 = "No Pain" to 10 = "Worst Imaginable Pain") where a higher score reflects greater pain intensity.

Low-Back Pain Specific Pain Intensity measures pain intensity using a single, 10-point ranked scale (score 0 = "No Pain" to 10 = "Worst Imaginable Pain") where a higher score reflects greater pain intensity.

The number of participants analyzed are participants who had a low back operation.

The number of participants analyzed are those who had a low back operation.

The Tobacco, Alcohol, Prescription medications, and other Substance (TAPS) Tool Part 1 is a 4-item screening for tobacco use, alcohol use, prescription medication misuse, and illicit substance use in the past year (i.e., previous 12 months). Each of the four multiple-choice items has five possible responses to choose from (0=Daily or Almost Daily to 4=Never). For each item, higher scores indicate better outcome.

The Tobacco, Alcohol, Prescription medications, and other Substance (TAPS) Tool Part 1 is a 4-item screening for tobacco use, alcohol use, prescription medication misuse, and illicit substance use in the past year (i.e., previous 12 months). Each of the four multiple-choice items has five possible responses to choose from (0=Daily or Almost Daily to 4=Never). For each item, higher scores indicate better outcome.

The Tobacco, Alcohol, Prescription medications, and other Substance (TAPS) Tool Part 1 is a 4-item screening for tobacco use, alcohol use, prescription medication misuse, and illicit substance use in the past year (i.e., previous 12 months). Each of the four multiple-choice items has five possible responses to choose from (0=Daily or Almost Daily to 4=Never). For each item, higher scores indicate better outcome.

The Tobacco, Alcohol, Prescription medications, and other Substance (TAPS) Tool Part 1 is a 4-item screening for tobacco use, alcohol use, prescription medication misuse, and illicit substance use in the past year (i.e., previous 12 months). Each of the four multiple-choice items has five possible responses to choose from (0=Daily or Almost Daily to 4=Never). For each item, higher scores indicate better outcome.

The Fear-Avoidance Beliefs - Physical Activity (FABQ-PA) questionnaire consists of 4 items measuring fear-avoidance of physical activity. A patient rates their agreement with each statement on a 7-point Likert scale where 0= completely disagree and 6=completely agree. The total score is the sum of individual questions with a total score range of 0-24. Higher scores indicate a greater tendency to avoid physical activity due to fear (i.e., higher fear-avoidance).

GAD-2 consists of 2 items and measures how often one has been bothered by anxiety-related problems. Each is answered with a score of 0 (not at all) to 3 (nearly every day). The total score is the sum of individual questions with a total score range of 0-6; the higher the score, the more frequent one is bothered by anxiety.

A 9-item questionnaire assessing physical and psychosocial factors that can contribute to persistent low back pain. The psychosocial subscale (5-items) helps differentiate between medium and high-risk groups. The first eight questions are disagree (0) or agree (1). The last question is a scale of 0 (Not at all) to 4 (Extremely). The total score ranges from 0-9 with higher scores indicating higher risk. The total raw score and subscore categorize low risk (total = 3 or less), medium risk (total = 4+ and subscore = 3 or less), and high risk (total = 4+ and subscore = 4+) groups.

A 10-item questionnaire used to measure disability related to low back pain. Each question is scored from 0-5 (minimum to maximum). The percentage of disability is the sum all the responses, divided by the total number of questions answered multiplied by 5, then multiplied by 100 (i.e., total scored / total possible score x 100). The score ranges from 0% (no disability) to 100% (most severe disability). Scores from 0% to 20% indicate minimal disability; 20% to 40%, moderate disability; 40% to 60%, severe disability; 60% to 80%, crippled; and 80% to 100%, bedbound or exaggerating.

A 10-item questionnaire used to measure disability related to low back pain. Each question is scored from 0-5 (minimum to maximum). The percentage of disability is the sum all the responses, divided by the total number of questions answered multiplied by 5, then multiplied by 100 (i.e., total scored / total possible score x 100). The score ranges from 0% (no disability) to 100% (most severe disability). Scores from 0% to 20% indicate minimal disability; 20% to 40%, moderate disability; 40% to 60%, severe disability; 60% to 80%, crippled; and 80% to 100%, bedbound or exaggerating.

A 6-item questionnaire used to assess pain-specific psychosocial construct comprising cognitive and emotional processes such as helplessness, pessimism, rumination about pain-related symptoms. The 5-point Likert scale responses are ranging from 0 (not at all) to 4 (all the time). Scores range from 0 to 24 with higher scores indicating greater pain catastrophizing.

Measures the presence of neuropathic pain by summing the Likert scale responses of 'never' (0) to 'very strongly' (5) for 7-items. The total raw score ranges from 0 to 35 with higher scores indicating a worse outcome.

The PHQ-2 is a 2-item Likert-scale (0=Not at all to 3=Nearly every day) screening tool to assess depression. The score has a range of 0 to 6. A score of 3 is the optimal cut point when using the PHQ-2 to screen for depression. A higher score indicates more likely depression.

HEAL is a validated item-bank comprised of 6 domains developed through the Patient Reported Outcomes Measurement Information System (PROMIS) methodology. HEAL measures patient-reported aspects of healing encounters and attitudes. This includes evaluating factors like the patient's perception of the communication with their provider, the overall quality of care, and their feelings about the treatment process. Range for raw score was 6 to 30 and a T-score range of 21.3 to 69.3. A T-score of 50 is equal to the mean and is considered normal. Higher scores indicate more positive perception.

The Patient-Reported Outcomes Measurement Information System (PROMIS) Cognitive Function and Abilities Short Form 2a assesses cognitive function and abilities. Raw scores (range 2 to 10) on the survey are converted to T scores (range 29.5 to 61.2), which are standardized scores based on the average in the population; a score of 50 would indicate meeting the average (mean) physical function T score in the reference general population, with a standard deviation of 10. Higher scores reflect greater cognitive function and abilities.

The GSS assesses sensory sensitivity across the five external senses, as well as interoception, based on Yes (1) or No (0) responses. The GSS external score is the sum of five items with scores ranging from 0 to 5 with a higher score indicating a worse outcome.

The GSS assesses sensory sensitivity across the five external senses, as well as interoception, based on Yes (1) or No (0) responses. The GSS interoception score is the sum of three items with scores ranging from 0 to 3 with a higher score indicating a worse outcome.

The GSS assesses sensory sensitivity across the five external senses, as well as interoception, based on Yes (1) or No (0) responses. The total score is the sum of all 8 items with scores ranging from 0 to 8 with a higher score indicating a worse outcome.

The Symptom Severity Index indicates severity of symptoms in the past week and past 6 months. The score ranges from 0 to 13 with a higher score indicating a worse outcome.

The Widespread Pain Inventory (WPI) measures chronic pain. The WPI score has a range 0-19. A higher score indicates more pain.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for transportation ranges from 0 (no) to 1 (yes) with 1 being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for healthcare needs ranges from 0 (no) to 1 (yes) with 1 being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for food insecurity ranges from 0 (never true) to 2 (often true) with a higher score being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for food money ranges from 0 (never true) to 2 (often true) with a higher score being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for health utilities ranges from 0 (no) to 1 (yes) with 1 being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for stable housing ranges from 0 (no) to 1 (yes) with 1 being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for emotional support ranges from 0 (no) to 1 (yes) with 1 being a worse outcome.

The SDOH screening tool is a questionnaire used to assess an individual's social needs, which can impact their health. The score for number of close friends ranges from 0-10 with a higher number indicating more friends.

Participants indicate how many times they have been treated unfairly over the course of their lives related to race/ethnicity. To score this scale, researchers add the number of events that happened at least once for the respondent. Higher scores on this scale mean more experiences of lifetime discrimination.

Participants indicate how many times they have been treated unfairly over the course of their lives related to orientation/gender identity. To score this scale, researchers add the number of events that happened at least once for the respondent. Higher scores on this scale mean more experiences of lifetime discrimination.

ACT is a form of cognitive behavioral therapy that is well established for the treatment of chronic pain. The goal of ACT is to build psychological flexibility thereby interrupting pain avoidance behavior patterns. Participants randomized to ACT will take part in 12 sessions over the course of 12 weeks. Sessions will be delivered as a combination of 4 remote face-to-face visits with a therapist and 8 therapist-supported online sessions (self-directed online modules supported by provider coaching). Online sessions will focus on helping participants accept pain, connect with negative thoughts and emotions, develop mindfulness and identify and commit to values and goals that are important to them. During face-to-face sessions with the therapist, participants will be encouraged to share their experience of skills practice and mastery, provide examples of skill use at home, and describe what barriers they encountered.

Duloxetine is a serotonin norepinephrine reuptake inhibitor (SNRI) that is FDA-approved for use in Chronic Low-Back Pain, and, as such, is included as a recommended therapy in nearly all current treatment guidelines for low back pain. Study participants will be treated with duloxetine for 12 weeks during the active treatment phase. At the time of randomization, the approved drug pharmacy at each study site will dispense between 185 and 192 duloxetine 30 mg capsules and provide to participants. This will ensure enough capsules to maintain up to a 60 mg dosage through the 12-week intervention phase and to taper the dose in the 13th week if needed.

Licensed physical therapists (PTs) or Doctors of Chiropractic (DCs) will rely on evidence-based guidance to direct decision-making on the particular type of manual and exercise therapy that may be best suited to an individual study participant. Special attention will be paid to the clinician's choice of language in regard to the purpose and expected outcomes of manual therapy in order to avoid enhancing catastrophizing ideations or preference for passive interventions. A total of 10 sessions will be provided over an 8-week treatment period. Two sessions per week are provided in the first two weeks followed by weekly sessions over the next 6 weeks. Treatment sessions will last approximately 60 minutes each.

The Enhanced Self-Care intervention will be comprised of educational modules on evidence-based cognitive-behavioral self-management skills for pain. These modules will be provided digitally for self-administration over a period of 12 weeks. There will be no therapist associated with the delivery of these educational materials; however, after the first four modules, email or text messages will be used to make personalized recommendations for accessing additional modules based upon identified problems from the baseline assessment. Additionally, the walking program module will utilize Fitbit step tracking to allow participants to monitor their walking progress.

Participants newly randomized to ACT in Stage 2 will take part in 12 sessions over the course of 12 weeks. Sessions will be delivered as a combination of 4 remote face-to-face visits with a therapist and 8 therapist-supported online sessions (self-directed online modules supported by provider coaching). Participants assigned to maintain ACT will be encouraged to continue at-home skills and will have access to all previously viewed online content. In addition, participants will have access to 11 additional online ACT audio modules, but without the communications with the therapist.

Study participants will be treated with duloxetine for 12 weeks during the active treatment phase. All participants will be assessed at the midpoint of the intervention treatment period (Week 18) for tolerance, adverse events, and response. At the midpoint phone call:

Participants tolerating the medication with no side effects will be instructed to increase to 60mg/day (if currently taking 30mg/day) or remain on their current dosage (if currently taking 60mg/day).

Participants newly randomized to EBEM in stage 2 will take part in a total of 10 sessions over an 8-week treatment period. Two sessions per week are provided in the first two weeks followed by weekly sessions over the next 6 weeks. Treatment sessions will last approximately 60 minutes each. Participants assigned to maintain EBEM will receive 4 additional in-person EBEM sessions during weeks 1-4 of this period. If visits are missed and/or need to be rescheduled, visits may be scheduled up to 5 weeks from the date of the first augmenting/maintenance visit.

Participants newly randomized to ESC in stage 2 will be provided modules digitally for self-administration over a period of 12 weeks. There will be no therapist associated with the delivery of these educational materials; however, after the first four modules, email or text messages will be used to make personalized recommendations for accessing additional modules based upon identified problems from the baseline assessment. Additionally, the walking program module will utilize Fitbit step tracking to allow participants to monitor their walking progress. Participants assigned to maintain ESC in the second period intervention will receive personalized recommendations based on the most recently completed PROMIS 29+2.

Participants received both ACT and duloxetine in Stage 2. Participants who received augmented Stage 2 treatments always continued their stage 1 treatment. The continued intervention matches the dose of those maintaining Stage 1 treatment alone, and the added intervention is as if they were newly randomized.

Participants received both ACT and EBEM in Stage 2. Participants who received augmented Stage 2 treatments always continued their stage 1 treatment. The continued intervention matches the dose of those maintaining Stage 1 treatment alone, and the added intervention is as if they were newly randomized.

Participants received both ACT and ESC in Stage 2. Participants who received augmented Stage 2 treatments always continued their stage 1 treatment. The continued intervention matches the dose of those maintaining Stage 1 treatment alone, and the added intervention is as if they were newly randomized.

Participants received both duloxetine and EBEM in Stage 2. Participants who received augmented Stage 2 treatments always continued their stage 1 treatment. The continued intervention matches the dose of those maintaining Stage 1 treatment alone, and the added intervention is as if they were newly randomized.

Participants received both duloxetine and ESC in Stage 2. Participants who received augmented Stage 2 treatments always continued their stage 1 treatment. The continued intervention matches the dose of those maintaining Stage 1 treatment alone, and the added intervention is as if they were newly randomized.

Participants received both EBEM and ESC in Stage 2. Participants who received augmented Stage 2 treatments always continued their stage 1 treatment. The continued intervention matches the dose of those maintaining Stage 1 treatment alone, and the added intervention is as if they were newly randomized.