Comparison of hernia registries: the CORE project
Randomized clinical trials (RCTs) and meta-analyses are considered the gold standard of evidence-based medicine nowadays . The strength of RCTs rests on their excellent internal validity, which is based largely on the power of randomization to ensure that the only difference between two treatment arms is their exposure to the treatment of interest . But the applicability of RCTs to the care of patients in routine practice is limited. In particular, patients, providers, and concurrent care in the general population are different from those in RCTs, and the generalizability or external validity of RCTs may be limited. Although observational research does not reach the same level of internal validity as RCTs, well-designed observational studies can offer high external validity and provide a unique opportunity to evaluate treatments and their outcomes in routine practice . Many important clinical questions have not, cannot, and will not be addressed in the context of an RCT. In these situations, clinicians rely on information provided by observa- tional research . In a comparison of observational studies and RCTs, the estimates of the treatment effects from observational studies and RCTs were similar in most cases . Registries are ongoing prospective observational data-collection repositories . A registry is defined as a systematic collection of a clearly defined set of health and demographic data for patients with specific health characteristics, held in a central database for predefined purposes . Medical registries can serve different purposes, for instance as a tool to monitor and improve the quality of care or as a resource for research . To be useful, data in a medical registry must be of good quality . To optimize the quality of medical registry data, the participating centers should follow certain procedures designed to minimize inaccurate and incomplete data . The intended use of registry data determines the necessary properties of the data .
In 1992, surgeons from eight Swedish hospitals initiated a registry for inguinal and femoral hernia repair . The aim of the registry was to report on the operative techniques used and to analyze outcome measures in order to stimulate quality improvement . A number of national and international registries have since been added [6–12]. The aim of this manuscript is to explore the databases of these hernia registries and compare them in content and outcome variables.