For the purpose of this report, manual treatment includes spinal and extremity joint manipulation or mobilization, massage and various soft tissue techniques. Manipulation/mobilization under anaesthesia was not included in the report due to the procedure's invasive nature. The conclusions of the report are based on the results of the most recent and most updated (spans the last five to ten years) systematic reviews of RCTs, widely accepted evidence-based clinical guidelines and/or technology assessment reports (primarily from the UK and US if available), and all RCTs not yet included in the first three categories. While critical appraisal of the included reviews and guidelines would be ideal, it is beyond the scope of the present report. The presence of discordance between the conclusions of systematic reviews is explored and described. The conclusions regarding effectiveness are based on comparisons with placebo controls (efficacy) or commonly used treatments which may or may not have been shown to be effective (relative effectiveness), as well as comparison to no treatment. The strength/quality of the evidence relating to the efficacy/effectiveness of manual treatment is graded according to an adapted version of the latest grading system developed by the US Preventive Services Task Force (see http://www.ahrq.gov/clinic/uspstf/grades.htm
). The evidence grading system used for this report is a slight modification of the system used in the 2007 Joint Clinical Practice Guideline on low back pain from the American College of Physicians and the American Pain Society [18
Through a search strategy using the databases MEDLINE (PubMed), Ovid, Mantis, Index to Chiropractic Literature, CINAHL, the specialized databases Cochrane Airways Group trial registry, Cochrane Complementary Medicine Field, and Cochrane Rehabilitation Field, systematic reviews and RCTs as well as evidence-based clinical guidelines were identified. Search restrictions were human subjects, English language, peer-reviewed and indexed journals, and publications before October 2009. In addition, we screened and hand searched reference citations located in the reviewed publications. The description of the search strategy is provided in Additional file 1
(Medline search strategy).
Although findings from studies using a nonrandomized design (for example observational studies, cohort studies, prospective clinical series and case reports) can yield important preliminary evidence, the primary purpose of this report is to summarize the results of studies designed to address efficacy, relative efficacy or relative effectiveness and therefore the evidence base was restricted to RCTs. Pilot RCTs not designed or powered to assess effectiveness, and RCTs designed to test the immediate effect of individual treatment sessions were not part of the evidence base in this report.
The quality of RCTs, which have not been formally quality-assessed within the context of systematic reviews or evidence based guidelines, was assessed by two reviewers with a scale assessing the risk of bias recommended for use in Cochrane systematic reviews of RCTs. Although the Cochrane Collaboration handbook http://www.cochrane.org/resources/handbook/
discourages that scoring be applied to the risk of bias tool, it does provide suggestion for how trials can be summarized. We have been guided by that suggestion and the adapted evidence grading system used in this report requires that we assess the validity and impact of the latest trial evidence. These additional trials are categorized as higher, moderate, or lower-quality as determined by their attributed risk of bias. For details, see Additional file 2
(The Cochrane Collaboration tool for assessing risk of bias and the rating of the bias for the purpose of this report).
The overall evidence grading system allows the strength of the evidence to be categorized into one of three categories: high quality evidence, moderate quality evidence, and inconclusive (low quality) evidence. The operational definitions of these three categories follow below:
High quality evidence
The available evidence usually includes consistent results from well-designed, well conducted studies in representative populations which assess the effects on health outcomes.
The evidence is based on at least two consistent higher-quality (low risk of bias) randomized trials. This conclusion is therefore unlikely to be strongly affected by the results of future studies.
Moderate quality evidence
The available evidence is sufficient to determine the effectiveness relative to health outcomes, but confidence in the estimate is constrained by such factors as:
• The number, size, or quality of individual studies.
• Inconsistency of findings across individual studies.
• Limited generalizability of findings to routine practice.
• Lack of coherence in the chain of evidence.
The evidence is based on at least one higher-quality randomized trial (low risk of bias) with sufficient statistical power, two or more higher-quality (low risk of bias) randomized trials with some inconsistency; at least two consistent, lower-quality randomized trials (moderate risk of bias). As more information becomes available, the magnitude or direction of the observed effect could change, and this change may be large enough to alter the conclusion.
Inconclusive (low quality) evidence
The available evidence is insufficient to determine effectiveness relative to health outcomes. Evidence is insufficient because of:
• The limited number or power of studies.
• Important flaws in study design or methods (only high risk of bias studies available).
• Unexplained inconsistency between higher-quality trials.
• Gaps in the chain of evidence.
• Findings not generalizable to routine practice.
• Lack of information on important health outcomes
For the purpose of this report a determination was made whether the inconclusive evidence appears favorable or non-favorable or if a direction could even be established (unclear evidence).
Additionally, brief evidence statements are made regarding other non-pharmacological, non-invasive physical treatments (for example exercise) and patient educational interventions, shown to be effective and which can be incorporated into evidence-based therapeutic management or co-management strategies in chiropractic practices. These statements are based on conclusions of the most recent and most updated (within last five to ten years) systematic reviews of randomized clinical trials and widely accepted evidence-based clinical guidelines (primarily from the UK and US if available) identified through our search strategy.
Translating Evidence to Action
Translating evidence requires the communication of salient take-home messages in context of the user's applications [3
]. There are two message applications for information derived from this work. First, the criteria for sufficiency of evidence differ depending on the context of the considered actions [8
]. Sufficient evidence to proffer claims of effectiveness is defined within the socio-political context [20
] of ethics and regulation. Separate is the second application of evidence to inform decision making for individual patients. Where there is strength of evidence and the risk of bias is small, the preferred choices require little clinical judgment. Alternatively, when evidence is uncertain and/or there is higher risk of bias, then greater emphasis is placed on the patient as an active participant [11
]. This requires the clinician to effectively communicate research evidence to patients while assisting their informed decision-making [19
In summary, the information derived within this report are directed to two applications 1) the determination of supportable public claims of treatment effectiveness for chiropractic care within the context of social values; and 2) the use of evidence information as a basis for individualized health care recommendations using the hierarchy of evidence (Figure ).