Review articleIs there a relationship between psychological stress or anxiety and chronic nonspecific neck-arm pain in adults? A systematic review and meta-analysis
Introduction
Chronic pain is usually defined as pain that lasts more than three months [1]. The prevalence of chronic pain is about 30% in Europe and entails a high economic and social burden for society [2]. Evidence suggests that conditions of chronic pain may be the result of an increase in the activity and a hyperexcitability of sensory neurons in the central nervous system, a process called central sensitization [3]. In conjunction with biological factors, the likelihood of appearance, development, and persistence of chronic pain has been extensively related to psychological and social risk factors [4], [5]. Furthermore, in the absence of peripheral nociceptive afferents, psychosocial factors such as stress or anxiety [6] can increase the descending facilitation of pain via sensitization and over activation of a number of pain-related areas in the forebrain and brainstem regions, a process called Cognitive-Emotional Sensitization [7], finally facilitating the perception of pain. However, the strength and the nature of this association between psychosocial factors and pain is far from being completely understood [8], [9].
Regarding neck pain, several studies have pointed out the considerable heterogeneity across findings and difficulties in presenting a real prevalence of this pain [10], [11]. It is considered that the 12-month prevalence of neck pain in the general population ranges between 30% and 50% [12], [13]. In relation to arm pain, in Netherlands, for instance, the 12-month prevalence of shoulder pain was 30.3% [14]. Further, complaints of the arms, neck, and shoulders affect most of the general population at least once in 15 years [15].
Due to its relatively highly variable clinical presentation [16], the term used in this study is Nonspecific neck-arm pain (NSNAP), which is used to describe symptoms in the upper quadrant related to heightened nerve mechanosensitivity, but without neurological deficits (i.e. no clinical signs of the presence of a radiculopathy) [17], [18]. In fact, a recent study based on 18 countries suggested that Generalised Musculoskeletal pain in neck/shoulder region tended to be more persistent over time than pain located in the neck or shoulder. Furthermore, this study suggested that widespread pain in the neck/shoulder was associated with somatizing tendency, older age, and poor mental health [19].
In chronic NSNAP, we have also considered subjects with pain induced by sudden acceleration-deceleration movement of the neck, which are called whiplash associated disorders (WAD). Despite the fact that they are classified as different groups, we have joined both and considered them as if they belonged to the same group, as long as selected studies included WAD patients comprehended between grade 0 and 2 [20], meaning that patients had no dislocation, fracture, or neurological deficit [21]. It is important to remark that up to 90% of WAD patients are diagnosed as grade I or II [22].
With regards to the management of chronic pain, at present, it remains unsatisfactory and has a poor prognosis for a significant proportion of patients [23]. This lack of evidence of effective interventions may be partly due to the afore mentioned multidimensional factors contributing to its appearance and development, but also due to the lack of knowledge on the precise associated psychosocial factors, its role on the pain system, how they are measured, and moreover, how strong their association to pain is [24]. Nevertheless, there is research currently seeking beneficial strategies to improve chronic pain. For instance, a recent study suggests that taking into account gender, anxiety, and depression in patients with chronic pain might be relevant in developing strategies for disease management [25]. According to this, a clear understanding of these relationships may allow clinicians to facilitate the approach to chronic NSNAP, providing information for the clinical decision-making, which includes prognosis, assessment, and management [26].
Based on the available scientific literature, this systematic review expands upon previous studies explicitly targeting a particular population of interest, and focusing on specific characteristics of outcome measures as a prognostic factor for chronic NSNAP.
The aim of this study is first to determine whether an association between anxiety or psychological stress factors and patients with chronic NSNAP exists, and second, to determine how strong this association is.
Section snippets
Methods
Our literature search aimed to identify all available studies that evaluated the association between stress or anxiety factors to chronic NSNAP in adults. We searched in Pubmed database from their inception to July 2015. The search terms used were: (“pain”[tiab] OR “musculoskeletal”[tiab]) AND (“neck”[tiab] OR “shoulder”[tiab] OR “arm”[tiab] OR “upper limb”[tiab] OR “NSNAP”[tiab] OR “upper quadrant”[tiab] OR “upper extremity”[tiab]) AND (“stress”[tiab] OR “anxiety”[tiab]), terms and text words
Study selection
We identified 3408 studies through database searching (Fig. 1). After screening by titles and abstracts of all remaining unique articles, 28 full-text articles needed to be assessed to verify their eligibility for the inclusion in the present study (Table 2). Four studies of these 28 selected articles, including 5 pair-wise comparisons, were included in the meta-analysis: 3 were cohort studies [31], [32], [33] and 1 was a cross-sectional study [34] (Table 3).
Study characteristics
The characteristics of studies are
Discussion
This updated meta-analysis and systematic review aimed to determine precisely the relationship of stress or anxiety factors in chronic NSNAP in adults. Four studies, including 5 pair-wise comparisons, with large sample sizes, mostly involving adults with chronic NSNAP, were selected and subjected to meta-analysis. The meta-analysis outcome showed that there was a relationship between chronic NSNAP and psychological stress (OR 95% 2.33 CI, 1.04–5.18) but the heterogeneity analysis (I2) was
Conclusions
This study shows that there is a strong relationship between stress and chronic NSNAP, but in spite of this, we have not found enough evidence to say that stress is a risk factor for chronic NSNAP due to the low quality of the results according to the GRADE. It was not possible to make a quantitative analysis comparing the relationship between anxiety and chronic NSNAP. However, according to the qualitative analysis there is a strong relationship between anxiety and chronic NSNAP. Ours findings
Funding sources and potential conflicts of interest
This study was not supported by any grant and the authors declare that there are no conflicts of interest.
Competing interest statement
No Conflict of Interest has been declared by the author(s).
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