Table 1: Eligibility criteria

Eligibility criteria

Table 1 Eligibility criteria
Eligibility criteria	Reference standard definition	Scope driven evidence-informed definition
Population “chronic” low back pain	According to the Pain Management Task Force [6][6], chronic pain can be described as ongoing or recurrent pain, lasting beyond the usual course of acute illness or injury or more than 3–6 mo, and which adversely affects the individual's well-being. In 2014, the National Institutes of Health Task Force on Research Standards for Low Back [22][22] recommended defining chronicity of pain as: “(1) How long has back pain been an ongoing problem for you? (2) How often has low-back pain been an ongoing problem for you over the past 6 months? A response of greater than 3 months to question 1, and a response of ‘at least half the days in the past 6 months’ to question 2 would define chronic low back pain.”	The majority of studies defined chronicity based on the duration of pain symptoms for 12 wk or more. Therefore, a similar definition of chronicity (≥12 wk) was adopted, and studies were categorized as those patients with >12 wk, a mean duration of 6 mo, and those with >12-mo pain duration.
Population “non-specific”	Non-specific low back pain is defined as pain not attributable to a recognizable, known specific pathology [23][23] (eg, infection, tumor, osteoporosis, fracture, structural deformity, rheumatoid arthritis, radicular syndrome). Therefore, the etiology of the pain is often unknown and it is not categorized with a major pathogenic etiology.	The existing literature does not use standard terminology to report “non-specific” chronic pain. To guide the eligibility of studies, the following terms were specified to be outside the scope of “non-specific”: specific conditions, ie, cancer, rheumatoid arthritis, fibromyalgia, spondylolisthesis (displacement of vertebra) and spinal stenosis (narrowing of spinal canal), pregnancy-related pain, and ankylosing spondylitis. Consensus among the internal steering committee specified the following exemptions: osteoarthritis, sciatica, radiculopathy, low back pain “of mechanical origin,” pain associated with spondylosis, sacroiliac joint syndrome, trauma-induced, disc herniation, pelvic anteversion, and “occupational” low back pain.
Interventions mobilization or manipulation	Bronfort et al. defined mobilization as “the application of manual force to the spinal joints within the passive range of joint motion that does not involve a thrust (p. 336)” [13][13]. The RAND report by Coulter et al. defines mobilization as “controlled, judiciously applied force of low velocity and variable amplitude directed to spinal joint segment(s)” (p. xi) [24][24].Spinal manipulation is defined as “the application of high-velocity, low amplitude manual thrusts to the spinal joints slightly beyond the passive range of joint motion,” by Bronfort et al. [13][13], where the RAND report by Coulter et al. defines spinal manipulation as “a controlled, judiciously applied dynamic thrust adjustment, that may include combined extension and rotation of the upper cervical spinal segments, or low-velocity and low-amplitude force with the use of a short or long lever directed to spinal joint segments within patient tolerance” (p. xi) [24][24].	The interventions in this systematic review consist of manipulation or mobilization in chiropractic settings and other non-invasive therapies including osteopathy, manual therapy and physical therapy. For simplicity, interventions were categorized into thrust and non-thrust interventions. When combined with other active interventions, they were labeled as “programs.”
Control/comparator(s)	This review focused on any intervention being compared with mobilization or manipulation, including any active therapy (ie, exercise, physical therapy), manipulation (thrust), mobilization (non-thrust), sham, no treatment, usual, or standard care.	For the purpose of analysis, controls or comparisons were categorized as active, sham, or no treatment, or as direct comparisons between various thrust and non-thrust interventions.
Outcome(s)	Although pain reduction was predefined as the primary outcome of interest, the most commonly reported pain-related, patient-reported outcomes that affect health status were determined through a scoping review and thus pooled to determine which could be assessed.	Patient-reported outcomes that the majority of studies include to date: pain intensity or severity (as measured by a VAS or NRS) disability (as measured by the RMDQ, HRQoL) as measured by the SF-36 or safety.
Study design(s)	All study designs were considered for the purposes of scoping the literature.	Randomized controlled trials were included in the systematic review and meta-analysis. Other study designs were queried when gaps were present (ie, safety).

Table 1 Eligibility criteria

Eligibility criteria

Reference standard definition

Scope driven evidence-informed definition

Population “chronic” low back pain

According to the Pain Management Task Force [6][6], chronic pain can be described as ongoing or recurrent pain, lasting beyond the usual course of acute illness or injury or more than 3–6 mo, and which adversely affects the individual's well-being. In 2014, the National Institutes of Health Task Force on Research Standards for Low Back [22][22] recommended defining chronicity of pain as: “(1) How long has back pain been an ongoing problem for you? (2) How often has low-back pain been an ongoing problem for you over the past 6 months? A response of greater than 3 months to question 1, and a response of ‘at least half the days in the past 6 months’ to question 2 would define chronic low back pain.”

The majority of studies defined chronicity based on the duration of pain symptoms for 12 wk or more. Therefore, a similar definition of chronicity (≥12 wk) was adopted, and studies were categorized as those patients with >12 wk, a mean duration of 6 mo, and those with >12-mo pain duration.

Population “non-specific”

Non-specific low back pain is defined as pain not attributable to a recognizable, known specific pathology [23][23] (eg, infection, tumor, osteoporosis, fracture, structural deformity, rheumatoid arthritis, radicular syndrome). Therefore, the etiology of the pain is often unknown and it is not categorized with a major pathogenic etiology.

The existing literature does not use standard terminology to report “non-specific” chronic pain. To guide the eligibility of studies, the following terms were specified to be outside the scope of “non-specific”: specific conditions, ie, cancer, rheumatoid arthritis, fibromyalgia, spondylolisthesis (displacement of vertebra) and spinal stenosis (narrowing of spinal canal), pregnancy-related pain, and ankylosing spondylitis. Consensus among the internal steering committee specified the following exemptions: osteoarthritis, sciatica, radiculopathy, low back pain “of mechanical origin,” pain associated with spondylosis, sacroiliac joint syndrome, trauma-induced, disc herniation, pelvic anteversion, and “occupational” low back pain.

Interventions mobilization or manipulation

Bronfort et al. defined mobilization as “the application of manual force to the spinal joints within the passive range of joint motion that does not involve a thrust (p. 336)” [13][13]. The RAND report by Coulter et al. defines mobilization as “controlled, judiciously applied force of low velocity and variable amplitude directed to spinal joint segment(s)” (p. xi) [24][24].Spinal manipulation is defined as “the application of high-velocity, low amplitude manual thrusts to the spinal joints slightly beyond the passive range of joint motion,” by Bronfort et al. [13][13], where the RAND report by Coulter et al. defines spinal manipulation as “a controlled, judiciously applied dynamic thrust adjustment, that may include combined extension and rotation of the upper cervical spinal segments, or low-velocity and low-amplitude force with the use of a short or long lever directed to spinal joint segments within patient tolerance” (p. xi) [24][24].

The interventions in this systematic review consist of manipulation or mobilization in chiropractic settings and other non-invasive therapies including osteopathy, manual therapy and physical therapy. For simplicity, interventions were categorized into thrust and non-thrust interventions. When combined with other active interventions, they were labeled as “programs.”

Control/comparator(s)

This review focused on any intervention being compared with mobilization or manipulation, including any active therapy (ie, exercise, physical therapy), manipulation (thrust), mobilization (non-thrust), sham, no treatment, usual, or standard care.

For the purpose of analysis, controls or comparisons were categorized as active, sham, or no treatment, or as direct comparisons between various thrust and non-thrust interventions.

Outcome(s)

Although pain reduction was predefined as the primary outcome of interest, the most commonly reported pain-related, patient-reported outcomes that affect health status were determined through a scoping review and thus pooled to determine which could be assessed.

Patient-reported outcomes that the majority of studies include to date: pain intensity or severity (as measured by a VAS or NRS) disability (as measured by the RMDQ, HRQoL) as measured by the SF-36 or safety.

Study design(s)

All study designs were considered for the purposes of scoping the literature.

Randomized controlled trials were included in the systematic review and meta-analysis. Other study designs were queried when gaps were present (ie, safety).

HRQoL, health-related quality of life; NRS, numeric rating scale; RMDQ, Roland-Morris Disability Questionnaire; SF-36, Short Form 36; VAS, visual analog scale.