IntroductionChronic pain is a debilitating condition with a high burden of disease. Neurostimulation therapy is an established modality for patients with chronic pain refractory to pharmacological based approaches and conservative interventional therapies. The therapy has evolved over the decades, based on improved understanding of the mechanisms of action, as well as technological advancement in device design.Our objective is to conduct a review of the innovation in neurostimulation therapy for chronic pain, in the context of health technology assessment (HTA), and its implications on policies related to patient access.MethodsA qualitative literature review was conducted to identify published HTAs, systematic reviews, clinical guidelines and other relevant articles and reports on neurostimulation therapies used in pain management. Searches were limited to the past 10 years to ensure that a contemporary analysis was conducted.ResultsOur review indicates that there has been continuous innovation in neurostimulation therapies for chronic pain. This includes improvements in battery longevity and reduced size, advances in the design of leads, the development of novel stimulation waveforms and personalized programming using sophisticated algorithms including sensing and feedback loops, and remote management to name a few. Clinical research has also enabled an expansion in the range of neural targets and indicated subpopulations. The literature shows that apart from reduction in pain, neurostimulation therapy facilitates improvements in the quality of life, and reduction in opioid dependence, carer burden and disability, which are outcomes important to patients as well as to society at large. Clinical guidelines are largely supportive of neurostimulation for the management of chronic refractory pain in carefully selected patients.ConclusionsThe range and complexity of neurostimulation devices and the variety of study designs presents a challenge for evidence synthesis. HTA bodies need to ensure that the methodologies for evaluating a heterogeneous therapy such as neurostimulation for pain management are robust, and that the policies for determining access to such innovative therapies are patient-centric and fit-for-purpose.