Review question/objective

The objective of this systematic review is to describe the effect of yoga on depression scores and pain in adult patients with chronic low back pain.

The specific review question is: What is the effectiveness of yoga on depression scores and pain of adult patients with chronic low back pain?

Background

Globally, low back pain is the most prevalent musculoskeletal condition which may result in a major burden to individuals, health systems and social care systems.1 Low back pain is a common problem encountered by clinicians in the primary care environment and is defined as pain between the 12th rib and the inferior gluteal folds which lasts more than three months.2,3 The pain may or may not radiate down the legs and 90% of cases of chronic low back pain are nonspecific and multifactorial in etiology.3,4 Chronic low back pain has been associated with decreased quality of life resulting in depression, sleep disturbances, stress, fatigue and medication abuse.5,6 Approximately 70% of adults will experience an episode of low back pain in their lifetime with a 90% recovery rate in one month.7 Chronic low back pain costs the United States approximately $62.5 billion per year.8 From 1997 to 2005 healthcare costs for persons with back pain increased by 65%.9 Chronic back pain has been shown to be the second leading cause of disability in the United States, and the leading cause of disability in persons younger than 45.1,8,10

Depression is a mental health disorder found worldwide, affecting more than 350 million people.11 Depression is one of the most prevalent and disabling mood disorders affecting persons in the labor force and in the general poulation.12,13 Depression symptoms can be varied and may include loss of interest or pleasure, feelings of sadness, low self-esteem, feelings of guilt, disturbances in sleep and appetite, exhaustion and poor concentration.11 Research has provided evidence that pain can increase the risk of depression and chronic pain increases depressive symptoms in patients.14 The prevalence of depression in patients with chronic low back pain is three to four times greater compared to the general population.15 Patients with chronic low back pain report decreased quality of life, and psychological factors, including depression, contribute significantly towards this perception.6 In a study by Hung et al., depression was found to be correlated with disability in patients with chronic low back pain.16 The economic burden of depression treatment is difficult to ascertain. It has been estimated that the annual cost of depression treatment in the United States alone exceeds $53 billion annually including direct and indirect costs.13 Common treatment options for depression include pharmacotherapy, individual or group counseling and watchful waiting.17 Evidence in the literature supports the use of yoga as a treatment option for depression.18

Chronic low back pain and functional disability are associated with higher depression scores and symptom severity among patients.5,19 Psychological manifestations, including depression, may cause chronic low back pain or result from it, and chronic low back pain increases the prevalence of depression in patients.5,16 Worldwide, the disease processes of pain and depression have been reported as being some of the most burdensome in society.19 Depression among chronic low back pain has also been linked to disability in patients.16

Yoga is a popular mind-body intervention which has shown some benefit in the management of chronic low back pain.3,4 Yoga originated in India thousands of years ago.8 It is a form of alternative or complementary medicine that incorporates a holistic approach.3,6 Yoga is defined as a combination of mental focus and physical activity which involves a series of body postures.20 Yoga advocates suggest that the practice creates inner physical and emotion balance through body postures and breathing techniques.3 Additionally, yoga has been identified as a cost-effective intervention as it can be delivered in group settings.20 Yoga teaches proper posture, body self-awareness and relaxation techniques.21 Yoga utilizes postures and positions which lead to a state of relaxation.1 Yoga, as a discipline, is designed to bring physical, emotional, spiritual and mental balance.22 Although yoga takes several forms, these underlying principles are applicable to most forms of yoga.

Multiple studies have shown that yoga can be an effective intervention in the management of chronic low back pain.23,24,25 Additionally, studies have shown that yoga reduces depression and pain symptoms in patients with chronic low back pain when compared to conventional exercise therapy, conservative management and no intervention.20,23, 24 Intervention comparators were chosen to reflect standard treatment guidelines and preliminary identification of studies.9 Yoga has been shown to improve back function and increase patient confidence in performing daily activities.21 Improvements in spine flexibility have also been noted.1,4 Research also suggests that yoga, as an intervention, results in decreased depression and anxiety, improvements in sleep, and an improved sense of well-being.5 Complete resolution of symptoms is rare. However, a reduction in pain as a result of yoga has been documented in the literature.2,5 The literature also suggests that the benefits of yoga impact multiple facets of chronic low back pain and depression.

Neurotransmitters have also been identified as playing a role in chronic low back pain and depression. The Brain-Derived Neurotrophic Factor (BDNF) is known to regulate sensory neurotransmission at the spinal level and is expressed with herniated discs.4 Additionally, antidepressants, which affect the serotonin system, have played a role in the management of chronic low back pain.4 Serotonin has been shown to remain at a stable level in study groups who participate in yoga, whereas it decreased significantly in control groups.4 Serum BDNF increased in yoga participants, while it tended to decline in control groups.4 Gamma-Aminobutyric Acid (GABA) levels rise in patients who participate in yoga, thus positively affecting mood and alleviating depression in these pateints.18 These findings suggest that yoga can affect neurotransmitters which can improve pain and depression symptoms in patients.

The purpose of this systematic review is to evaluate the effectiveness of yoga on depression scores and pain in patients with chronic low back pain. It will evaluate studies which measure depression scores utilizing the Beck Depression Inventory (BDI) as the measurement tool. To analyze the data, the review will only evaluate studies that utilize this tool. The BDI is one of the most common outcome measurement tools for assessing successful treatment in chronic low back pain.26 Additionally, this tool has been validated and found to be reliable in populations with chronic low back pain.26

While there are studies which have evaluated the effectiveness of yoga on depression scores of adult patients with chronic low back pain, there is no published systematic review in the Cochrane Database of Systematic Reviews, the Joanna Briggs Institute Database of Systematic Reviews and Implementation Reports, or the Campbell Systematic Reviews. This systematic review will seek to further evaluate this aspect from a quantitative perspective through literature synthesis and analysis of data.

Inclusion criteria

Types of participants

This review will consider studies of males and females 18 years or older diagnosed with chronic low back pain who have participated in yoga as an intervention for their condition. Participants must have had low back pain symptoms that have persisted for at least 12 weeks in order for the study findings to be considered in the systematic review. Participants may or may not have participated in yoga prior to their inclusion in the reviewed study. Study participants do not need to have a diagnosis of depression in order to be considered for the review.

Types of intervention(s)/phenomena of interest

This review will consider studies that evaluate depression scores and pain in patients who practice yoga as an intervention for chronic low back pain. Yoga, as the intervention of interest, will include any type such as Iyengar, Viniyoga and Hatha. Participants in included studies must practice yoga at least once per week for at least four weeks to be included in the systematic review. The practice may occur in a variety of settings including group settings, home settings or in private yoga studio settings. Comparators for this review will be usual care and may include no specific treatment, conservative management or physical therapy.

Types of outcomes

This review will consider studies that include the Beck Depression Inventory as the outcome for depression. Pain will also be evaluated, utilizing the numeric pain scale, as a secondary outcome measure.

Types of studies

This review will consider both experimental and epidemiological study designs including randomized controlled trials, non-randomized controlled trials, quasi-experimental studies, before and after studies, prospective and retrospective cohort studies, case control studies and analytical cross sectional studies for inclusion. The quantitative review will also consider descriptive epidemiological study designs including case series, individual case reports and descriptive cross sectional studies for inclusion.

Search strategy

The search strategy aims to find both published and unpublished studies. A three-step search strategy will be utilized in this review. An initial limited search of MEDLINE and CINAHL will be undertaken followed by an analysis of the text words contained in the title and abstract, and of the index terms used to describe the article. A second search using all identified keywords and index terms will then be undertaken across all included databases. Thirdly, the reference list of all identified reports and articles will be searched for additional studies. Studies published in English will be considered for inclusion in this review. There will be no date limitations for inclusion in the review.

The databases to be searched include:

MEDLINE (EBSCO), CINAHL, PsycINFO and EMBASE.

The search for unpublished studies will include:

Google Scholar, Mednar, Grey Literature Report through NYAM (New York Academy of Medicine) and ProQuest Dissertations and Theses.

Initial keywords to be used will be:

Chronic low back pain, low back pain, back pain, lumbago, backache, sciatica

Psychological disorder, depression, major depression disorder, Beck Depression Inventory

Yoga, asana, pranayama

Assessment of methodological quality

Manuscripts selected for retrieval will be assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) (Appendix I). Any disagreements that arise between the reviewers will be resolved through discussion, or with a third reviewer.

Data extraction

Quantitative data will be extracted from papers included in the review using the standardized data extraction tool from JBI-MAStARI (Appendix II). The data extracted will include specific details about the interventions, populations, study methods and outcomes of significance to the review question and specific objectives.

Authors of primary studies will be contacted for missing information or to clarify ambiguous data.

Data synthesis

Quantitative data will, where possible be pooled in statistical meta-analysis using JBI-MAStARI. All results will be subject to double data entry. Effect sizes expressed as weighted mean differences (for continuous data) and their 95% confidence intervals will be calculated for analysis. Heterogeneity will be assessed statistically using the standard Chi-square and also explored using subgroup analyses based on the different study designs included in this review. Subgroup analyses will be utilized to explore the relationship between different comparator interventions in the selected studies. Where statistical pooling is not possible the findings will be presented in narrative form including tables and figures to aid in data presentation where appropriate.

Conflicts of interest

The authors have no conflicts of interest to declare.

Acknowledgements

This systematic literature review is being undertaken as part of the requirements for a Doctorate in Nursing Practice (DNP) degree for Julie A Brinzo.

References