The topic of medical cannabis has taken centre stage in recent years, attracting discussion from doctors, researchers, regulators, and patients alike. In Australia, access to legal medicinal cannabis is granted under the Therapeutic Goods Administration (TGA) Special Access Scheme. An application stating the medical reason for accessing cannabis must be submitted by a doctor on behalf of their patient. This regulatory framework is time-consuming and has been described as a process fraught with obstacles and rejections. Doctors are often caught in a conundrum, where they are balancing the demands and/or needs of patients with adherence to the principles of evidence-based medicine. N-of-1 trials may provide a perfect solution for this problem by generating evidence to support prescribing decisions.
The evidence supporting medical cannabis in chronic pain
Medical cannabis has been increasingly studied for its potential benefits in managing chronic pain. According to a systematic review and meta-analysis of 32 randomised controlled trials (5,174 adult patients) published in the British Medical Journal, there is moderate to high quality evidence that medical cannabis or cannabinoids result in a small improvement in pain relief, physical functioning, and sleep quality among patients with chronic pain, along with several transient adverse side effects, compared to placebo. However, the evidence on the use of medical cannabis for chronic pain is mixed. For example a 4-year prospective cohort study published in The Lancet Public Health concluded there was no evidence that cannabis use reduced pain severity in people with chronic non-cancer pain.
Challenges in the field of medical cannabis
There is a scarcity of evidence generated from traditional RCTs, which doctors typically rely on for prescribing decisions. The evidence on the effectiveness of medical cannabis for chronic pain is limited by small sample sizes and the short follow-up periods. Another limitation is the use of study designs that do not adequately account for variability in response to medical cannabis across patients. Traditional randomised controlled trials often produce “one-size-fits-all” conclusions based on aggregated data from multiple participants. However, response to medical cannabis can be heterogeneous, where one patient may respond well, and the next patient may not. N-of-1 trials would provide an excellent approach for evaluating response to medical cannabis at the individual patient level, which traditional randomised controlled trials cannot.
What are N-of-1 trials?
N-of-1 trials involve testing treatments in an individual patient, where they serve as their own control. One of the benefits of using N-of-1 trials is that they offer a valuable scientific approach to gathering evidence in the absence of traditional randomised controlled trials. In addition, they can be highly informative for making treatment decisions for individual patients. Pooling data collected from multiple N-of-1 trials provides additional value. A pooled N-of-1 study enhances statistical power and offers a robust approach to generating evidence about the effects of therapeutic products, where conclusions can be drawn about individuals and larger groups of patients. Individual and pooled N-of-1 trials could play a crucial role in generating evidence to support medical cannabis prescribing decisions.
N-of-1 Hub is a consulting company that specialises in designing, conducting, and analysing personalised clinical studies using N-of- trials and single-case designs. N-of-1 Hub also offers data management and analysis services and customised training workshops.
For further information about N-of-1 Hub, and to discuss your study needs, please contact us.