Review ArticleTraditional needle acupuncture treatment for insomnia: A systematic review of randomized controlled trials
Introduction
Insomnia is the most common sleep complaint, with approximately 9–15% of the general population worldwide suffering from insomnia symptoms accompanied by daytime consequences [1]. The prevalence of insomnia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria is roughly 6% [1]. Primary insomnia and insomnia related to mental disorders are the two most frequent diagnoses among subjects with insomnia complaints [1], [2], [3]. The literature suggests that relationships exist between insomnia and major depression, anxiety disorders, substance abuse, suicide, decreased immune functioning, and cardiovascular disease [4]. Insomnia may lead to fatigue, irritability, and impaired concentration. It is associated with reduced quality of life, increased risk of traffic accidents, absenteeism, and impaired job performance [5], [6]. The economic impact of insomnia is high. A recent study found that the 6-month direct and indirect costs for adults with insomnia in the United States were $1,253 greater than that for matched controls without insomnia [7].
Although psychological, behavioral, and pharmacological therapies are effective treatments for insomnia, they have their own limitations. Psychological and behavioral therapies have remained largely underutilized, perhaps due to their time intensiveness and because they require significant expertise for effective implementation [8]. Pharmacotherapies such as benzodiazepines and non-benzodiazepine hypnotics are associated with dependence and potential abuse. Moreover, adverse effects such as sedation, cognitive impairment, and lack of motor coordination could be troublesome. Faced with the limitations of currently available treatments, patients have been using alternative therapies for insomnia [9].
A national survey in the United States showed that use of complementary and alternative medicine in treating insomnia has increased from 20.6% in 1990 to 26.4% in 1997 [9]. Among the complementary treatment modalities, acupuncture has been one of the most popular and safest procedures [10]. The acupuncturists insert fine needles at special points on the body, called acupoints, followed by manual or electrical stimulation. Traditional needle acupuncture (TNA) is usually performed according to the traditional Chinese medicine (TCM) theory [11]. Modified forms of acupuncture include laser acupuncture, acupressure, auricular therapy, and transcutaneous electrical nerve stimulation. The overall TCM model for the action of acupuncture is that normal body functioning involves regulation of Yin and Yang, Qi, along with blood and body fluids; while any disturbance of the homeostasis would lead to diseases [11]. Acupuncture treatment is able to restore the balance between Yin and Yang and normalize the flow of Qi, blood and body fluid by stimulating the acupoints on the meridian [11]. There are two main acupuncture approaches. The more commonly used individualized acupuncture requires the acupuncturists to select acupoints based on patients’ clinical state and response to acupuncture treatment [12]. The standardized acupuncture refers to the use of a set of fixed acupoints throughout the treatment course [13].
Because of the significant health risk of insomnia and the limitations of currently available treatments, there have been multiple anecdotal reports and controlled studies over the past decade to examine the efficacy of acupuncture for insomnia. Systematic reviews [14], [15], [16] on acupuncture for insomnia have also been published recently. However, previous reviews only covered English language literature and had not evaluated the standard in reporting acupuncture treatment. Auricular acupuncture, introduced by Paul Nogier in the 1950s, was also used in the treatment of insomnia. Recently, Chen et al. provided a systematic review on randomized controlled trials (RCTs) of auricular acupuncture for insomnia [17], in which the majority of the RCTs included were in Chinese. Although the review suggests that auricular acupuncture may be effective for treating insomnia, the qualities of the RCTs were low [17].
As many studies of TNA for insomnia have been published in non-Western scientific literature and have not been reviewed, it is therefore worthwhile to undertake a systematic review of RCTs using TNA as treatment for insomnia that were published in either English or Chinese. This study aimed to examine the efficacy of TNA for insomnia, the acupuncture regime used, the quality of the RCTs, and the standard in reporting acupuncture treatment [13]. Although TNA and auricular acupuncture are commonly used acupuncture options for treating insomnia and sometimes used concomitantly in clinical practice [11], auricular acupuncture was not included in this review because it is not based on the TCM theory [18] and its effects appear to be associated with stimulation of the vagal afferent nerve, which is not involved in body acupuncture [19], [20]. Other modified acupuncture practices such as acupressure and laser acupuncture were also not included in this review because the techniques used for acupoint stimulation are different from that in TNA.
Section snippets
Methods
We searched MEDLINE (1966–2006), EMBASE (1980–2006), Cochrane Central Register of Controlled Trials (1997–2006), PsycINFO (1887–2006), Dissertation Abstracts International (1861–2006), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982–2006), and Allied and Complementary Medicine (AMED) (1985–2006) in September 2006 using the grouped terms (acupuncture*, acupunc*, meridian* or acupoint*) and (sleep*, insomnia*, wakeful* or sleepless*). The search included Chinese Scientific
Description of the studies
The search yielded 577 potential article titles for review, of which 536 articles were excluded for reasons of irrelevance (Fig. 1). Forty-one clinical trials assessing the application of needle acupuncture for insomnia were retrieved for further assessment. Among these 41 trials, 18 did not include sham or placebo control, Western medication or non-treated control [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41]. One of the studies was
Discussion
The study reviewed the efficacy of TNA in treating insomnia. The results of this review seemingly suggested that TNA was overall superior to benzodiazepine, sleep hygiene counseling, and sham acupuncture in the acute treatment of insomnia. Of the 20 RCTs that were reviewed, 18 studies were conducted in China [46], [47], [48], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63], [64]. These studies all scored 2 or less by the modified Jadad scale and were deemed to
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