In a 1974 World Health Organization Publication, E. M. Brooke introduced the general concept of patient registries in health information systems as documents about individual persons that are collected systematically for a specific purpose. Increasingly, patient registries have been used for the express purpose of evaluating patient outcomes. These registries have been more specifically defined as “an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure, and that serves one or more predetermined scientific, clinical, or policy purposes.”

Currently, in the United States, there is an increasing call for defining and assigning health care value based on quality and cost/benefit analysis in an effort to drive health care reform and decrease the overall cost of health care. In this model, value, in its simplest form, is evaluated as patient-based outcomes divided by related costs of care. Although randomized clinical trials (RCTs) are widely accepted as the gold standard for evidence-based practices, important limitations in their generalizability remain. Specifically, the same factors that ensure high internal validity, such as strict inclusion/exclusion criteria and homogenous populations, also inherently limit the ability to generalize these conclusions to populations not represented in these studies. It has been reported that enrollment in RCTs in spine surgery is often less than 50% owing to hesitation to participate by either the surgeon or the patient, leading to potentially nonrepresentative patient populations ultimately being enrolled. Other limiting factors include cost and scalability. These limitations have been highlighted specifically in spine surgery research, with strict randomization and quality control efforts resulting in artificially higher effect sizes. When collected appropriately, real-world data from registries have many advantages over that gleaned from traditional clinical trials, including scalability, cost effectiveness, and better generalizability (external validity).

There has been widespread advocacy on the national front for the use of prospective registries as a way to drive health care reform, as evidenced by health reform packages funding and expanding the role of “comparative effectiveness research” in determining cost effectiveness. The formation of prospective registries for collecting data on health care outcomes and effectiveness is one avenue to facilitate evidence-based practices and value assessments in a generalizable and cost-effective manner. When appropriately designed, quality registries can be used to generate high-level evidence (level 1 prognostic/predictive evidence and level 2 evidence on effectiveness). The trend in spine surgery has been toward building and maintaining such registries to allow for high-quality data collection and analysis that are specific to a given procedure or surgical paradigm. This chapter addresses the goals of these registries, documents their current status and contribution to the spine literature, and finally discusses future avenues and potential pitfalls of this system.