Durable Effect of Acupuncture for Chronic Neck Pain: A Systematic Review and Meta‑Analysis

Chronic neck pain is a very common health problem that affects millions of people around the world. This condition, characterized by pain that persists for more than three months in the cervical region, can radiate to the head and upper limbs, causing significant impact on patients' quality of life. It is estimated that about 67% of people will experience neck pain at some point in their lives, and approximately 20% of these cases will progress to chronic pain. The problem is particularly prevalent among workers who spend long hours seated or in inadequate static positions.

Beyond physical suffering, chronic cervical pain represents a significant economic and social burden, often leading to time off work and limiting daily activities. Conventional treatments, such as anti-inflammatory medications and physical therapy, although they may offer temporary relief, often have limitations regarding the durability of results and can cause significant side effects.

This study aimed to evaluate whether acupuncture offers lasting benefits for patients with chronic cervical pain. Researchers conducted a systematic review and meta-analysis, a type of research that gathers and rigorously analyzes all available scientific studies on a specific topic. The search was performed in six major medical databases, including English- and Chinese-language publications through March 2024, initially identifying 7,639 studies. After rigorous selection based on predefined criteria, 18 randomized controlled studies were included in the final analysis.

Researchers focused specifically on studies that evaluated the effects of acupuncture for at least three months after the end of treatment, as this period is considered adequate to assess durable benefits. The main outcomes analyzed were pain intensity, neck functionality, and patients' quality of life. The methodological quality of the studies was evaluated using standardized tools to identify potential biases that could compromise the reliability of the results.

The results revealed important and nuanced findings on the efficacy of acupuncture. When used as a complementary treatment alongside other conventional therapies, acupuncture demonstrated the ability to provide pain relief sustained for at least three to six months after the end of treatment. This finding is particularly relevant, as it suggests that the benefits of acupuncture extend well beyond the period of needle application. However, when compared directly with sham acupuncture (in which blunt needles are applied at non-therapeutic points), true acupuncture did not show a statistically significant difference in pain relief.

This may suggest that some of the beneficial effects observed could be related to placebo factors or patient expectations. Interestingly, acupuncture demonstrated superiority over sham acupuncture in functional improvement, specifically when assessed by the Northwick Park Neck Pain Questionnaire at three months post-treatment. As for safety, the profile of acupuncture was very favorable, with adverse events reported in only 8.5% to 13.8% of cases, all mild and temporary in nature, such as small local bleeding, hematomas, or pain at the application site.

The clinical implications of these results are significant for both patients and health care professionals. For patients suffering from chronic cervical pain who seek alternatives to conventional treatments, acupuncture emerges as a safe therapeutic option that can offer lasting benefits, especially when integrated into a comprehensive treatment plan. The capacity of acupuncture to provide sustained functional improvements is particularly valuable, as it translates into greater capacity to perform daily activities and a potential reduction in the need for frequent treatments. For health care professionals, these findings suggest that acupuncture may be considered a valuable adjunctive strategy in the management of chronic cervical pain, especially given its excellent safety profile compared with the risks associated with prolonged use of anti-inflammatory medications.

The fact that acupuncture as complementary therapy showed superior efficacy when compared with isolated treatment suggests that its integration into multimodal treatment protocols can optimize therapeutic results. Furthermore, the durability of the observed effects may contribute to reducing the frequency of medical consultations and dependence on medications, resulting in economic benefits for both patients and the health care system.

However, it is important to recognize the limitations of this research. The methodological quality of many included studies was considered moderate to low, mainly due to inherent difficulties with "blinding" in acupuncture studies, where it is challenging to conceal from patients whether they are receiving real or sham treatment. The heterogeneity among studies in terms of acupuncture protocols, populations studied, and types of control used may also have influenced the results. Additionally, some studies did not adequately report possible additional treatments that patients may have received during the follow-up period, which could confound interpretation of the results.

The limited number of studies for some specific outcomes also restricts the robustness of the conclusions. Despite these limitations, the authors emphasize that the findings provide encouraging evidence on the potential of acupuncture as a safe and effective complementary therapeutic approach for the management of chronic cervical pain, justifying the need for future studies with greater methodological rigor and larger samples to confirm and expand these promising results.