Survey-based variables that complemented the registry-based variables were covered in this systematic literature review, but their role was peripheral, given possible self-reporting bias missing independent validation, the quality of their evidence may have been suboptimal.
16 Conducting prospective, randomized, controlled, open-label clinical trials, with identification of patients and evaluation of endpoints based on high-quality registries, may complement the strengths and address the weaknesses of both randomized clinical trials and comparative observational registry studies.
This retrospective population-based observational study used prospectively collected cardiac arrest registry data complemented with laboratory data.
Robust analyses of observational patient registries would complement our findings and better deal with some of these issues, although the lack of blinding and perceptions of methotrexate and lung disease would be of some concern.
For example, Miller 2000 investigated public and private worldwide credit data and concluded that public credit registries were not a substitute for private sector registries but a complement.
However, registry-based randomized trials may complement the strengths and address the weaknesses of registries and trials by lowering costs, facilitating recruitment and providing real-world populations created from consecutively enrolled registry patients [ 78, 79].
Such registry studies are complemented by data such as in the BAFTA study, which are not subject to the potential ascertainment bias of registries and are controlled for use of drug treatments.
Alternatively, a registry may quote the complement (in probability) of the KM survivorship function.
In rheumatology, various observational cohorts and registries have been created to complement information obtained from RCTs, some with the primary purpose of monitoring effectiveness and safety of biologic agents.
6– 9 In this therapy area, there is an established precedent of assessing the response to and safety of long-term treatment with GH and of supporting and complementing the clinical trial evidence base through registry tools.
