Dose-response relationship between acupuncture time parameters and the effects on chronic non-specific low back pain: a systematic review and Bayesian model-based network meta-analysis protocol

Chronic low back pain represents one of the greatest public health challenges worldwide, affecting millions of people and constituting one of the leading causes of disability on the planet. About 90% of cases are classified as nonspecific low back pain, meaning they have no clearly identifiable anatomic cause, such as fractures, tumors, or infections. This condition is characterized by pain, muscle tension, or stiffness in the lumbar region that persists for more than 12 weeks, with or without pain radiating into the legs. What makes this condition particularly concerning is its tendency to become chronic: studies show that 67% of people with nonspecific low back pain continue to experience pain after three months, and 45% still have symptoms after one year.

Beyond physical suffering, psychological factors frequently accompany the condition, creating a complex cycle that can perpetuate pain and significantly limit patients' quality of life.

Given the risks associated with prolonged use of opioid medications and the limited efficacy of many conventional pharmacologic treatments, non-drug therapies such as acupuncture have gained increasing prominence. Acupuncture, an ancient traditional Chinese medicine technique that involves the insertion of fine needles at specific points on the body, has demonstrated efficacy in relieving pain and improving negative emotions associated with chronic suffering. It is currently recommended as a first-line treatment in several international clinical protocols for low back pain and is even covered by the U.S. Medicare program.

However, one fundamental question remains without a clear answer: what is the ideal 'dose' of acupuncture to achieve the best therapeutic results?

This innovative study aims to fill this important gap in scientific knowledge. The researchers propose conducting a systematic review and network meta-analysis using Bayesian methods to investigate the dose-response relationship between the time-related parameters of acupuncture and its effects on chronic nonspecific low back pain. Specifically, they intend to determine the optimal number of sessions, the optimal frequency of treatments, and the most effective overall duration of treatment. The methodology is rigorously structured, following established international protocols for systematic reviews.

The researchers will conduct comprehensive searches across multiple medical databases, including both Western and Eastern literature, from inception through July 2023. Only randomized controlled trials evaluating adults with chronic nonspecific low back pain treated with body acupuncture, whether manual or electrostimulated, will be included. The primary outcome will be improvement in pain intensity measured by validated scales at different time points during treatment.

The expected preliminary results of this study are promising and clinically relevant. For the first time in the scientific literature, it will be possible to have robust evidence on optimal time-related parameters of acupuncture for chronic low back pain. The analysis will use advanced statistical methods that will not only allow comparison of different acupuncture 'doses' but will also mathematically model the relationship between treatment quantity and benefit obtained. This means the researchers will be able to identify, for example, whether there is a minimum number of sessions necessary to achieve significant pain relief, whether there is a saturation point beyond which additional sessions provide no further benefit, and what the optimal treatment frequency is for maximizing results.

In addition, the study will assess not only efficacy but also safety, carefully documenting any adverse effects associated with the different treatment regimens. This comprehensive approach will provide health care professionals with valuable information to personalize treatment according to each patient's individual needs.

The clinical implications of these findings are substantial for both patients and health care professionals. For patients, having acupuncture protocols based on solid scientific evidence means more effective treatments, with a higher likelihood of pain relief and improved physical function, while avoiding excessively long or insufficient treatments. From an economic standpoint, determining the optimal dose of acupuncture may result in more efficient use of health care resources, avoiding both undertreatment and overtreatment. For acupuncturists and other health care professionals, this study will offer practical evidence-based guidance for clinical decision making, replacing empirical protocols with scientifically grounded recommendations.

This is particularly important considering that there is currently substantial variation in clinical practice, with some practitioners recommending daily treatments while others suggest weekly sessions, and total treatment durations varying dramatically across providers.

However, it is important to acknowledge the limitations inherent to this type of research. A significant limitation is the potential heterogeneity among the studies included, especially considering the differences between research conducted in Eastern and Western countries, which may reflect variations in acupuncture techniques, point selection, and patient characteristics. Furthermore, comparison between manual and electrostimulated acupuncture may introduce additional variability into the results. Another important methodological aspect is that many studies will use sham acupuncture as a control, which may underestimate the true therapeutic effects of real acupuncture.

Despite these limitations, the researchers will implement sophisticated analytic strategies to minimize their impact, including subgroup analyses and rigorous assessments of methodological quality for each included study.

This research protocol represents a significant advance in the pursuit of evidence-based medicine in the field of acupuncture. By providing robust scientific data on the optimal dosage of acupuncture for chronic low back pain, the study will help standardize and improve clinical practice, benefiting both patients and the health care system as a whole. The expected results will not only guide current clinical practice but will also establish a methodology that can be applied to investigate optimal acupuncture parameters in other medical conditions, paving the way for a more scientific and personalized approach to this ancient healing art.