No differences were found between effect estimates from conventional and registry-based randomized controlled trials

A methodological review identified several options for utilizing registries for randomized controlled trials

OBJECTIVES

Registry-based randomized controlled trials (RRCTs) can provide internally valid results in a real-world context at relatively low effort and cost. However, the main characteristics, the extent to which the registry is utilized (eg, proportion of data from registry) and registry-related limitations are not well characterized. This methodological review of RRCTs aims to analyze the trial design features, investigate potential usage options, and identify possible limitations of using registry data for randomized controlled trials (RCTs).

STUDY DESIGN AND SETTING

A systematic search in PubMed for ongoing and published RRCTs was conducted up to February 2, 2023. Studies that reported at least one outcome derived from a registry were included. Study selection was independently performed by two reviewers. All data were extracted into a standardized table, and descriptive statistics were generated.

RESULTS

We included 162 RRCTs (41 protocols and 121 studies). Most RRCTs were multicenter trials (n = 127; 78.4%) comprising a large number of participants (median = 1787; range = 41 to 683,927) and a long follow-up period (median = 60 months; range = 1 to 367 months) with a minimal loss to follow-up. The inclusion criteria of participants were mostly broadly defined. Types of interventions ranged from surgical procedures to behavioral interventions, and almost half of the interventions (46.9%) had a preventive purpose. The main registry outcome was mostly a clinical endpoint (40.1%) or a composite endpoint of major clinical events (30.9%) that was objectively measurable. We found different degrees of registry utilization, ranging from the exclusive use of long-term monitoring of previously published data to the more comprehensive registry utilization for patient recruitment, endpoint collection, and long-term follow-up. Limitations related to the use of registry data comprised potential coding errors or incomplete data (eg, due to under-recording of mild cases). In addition, technical challenges must be considered (eg, failed linkages or time-delayed data entry).

CONCLUSION

A broad spectrum of potential usage options and usage extent of registry data exist. Our analysis suggests that in many cases, the potential of using registry data and thus their benefits were not fully utilized. In addition, the study illustrates that there is not a single, unified methodology for designing RRCTs but that registries can support RCTs in various ways. Therefore, future RRCTs should specify for what purposes and to what extent registries were utilized. Moreover, a clear definition and taxonomy of RRCTs appears necessary for facilitating future dialogue and research on RRCTs.

The role of national population-based registries in pancreatic cancer surgery research

Research and innovation are critical for advancing the multidisciplinary management of pancreatic cancer. Registry-based studies (RBSs) are a complement to randomized clinical trials (RCTs). Compared with RCTs, RBSs offer cost-effectiveness, larger sample sizes, and representation of real-world clinical practice. National population-based registries (NPBRs) aim to cover the entire national population, and studies based on NPBRs are, compared to non-NPBRs, less prone to selection bias. The last decade has witnessed a dramatic increase in NPBRs in pancreatic cancer surgery, which has undoubtedly added invaluable knowledge to the body of evidence on pancreatic cancer management. However, several methodological shortcomings may compromise the quality of registry-based studies. These include a lack of control over data collection and a lack of reporting on the quality of the source registry or database in terms of validation of coverage and data completeness and accuracy. Furthermore, there is a significant risk of double publication from the most commonly used registries as well as the inclusion of historical data that is not relevant or representative of research questions addressing current practices.

[Future of registries]

Medical registries play a crucial role in contemporary medicine by providing valuable information for clinical practice, research, and health policies. Systematic performance assessment, including patient input, linkage with medical-administrative databases, integration of randomized studies, and the use of artificial intelligence, mark an exciting new era for medical registries. These advancements will transform the way we understand, prevent, and treat diseases, paving the way for a more personalized, predictive, efficient, and likely cost-effective medicine.

Treatment effects in randomised trials using routinely collected data for outcome assessment versus traditional trials: meta-research study

OBJECTIVE

To compare effect estimates of randomised clinical trials that use routinely collected data (RCD-RCT) for outcome ascertainment with traditional trials not using routinely collected data.

DESIGN

Meta-research study.

DATA SOURCE

Studies included in the same meta-analysis in a Cochrane review.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Randomised clinical trials using any type of routinely collected data for outcome ascertainment, including from registries, electronic health records, and administrative databases, that were included in a meta-analysis of a Cochrane review on any clinical question and any health outcome together with traditional trials not using routinely collected data for outcome measurement.

REVIEW METHODS

Effect estimates from trials using or not using routinely collected data were summarised in random effects meta-analyses. Agreement of (summary) treatment effect estimates from trials using routinely collected data and those not using such data was expressed as the ratio of odds ratios. Subgroup analyses explored effects in trials based on different types of routinely collected data. Two investigators independently assessed the quality of each data source.

RESULTS

84 RCD-RCTs and 463 traditional trials on 22 clinical questions were included. Trials using routinely collected data for outcome ascertainment showed 20% less favourable treatment effect estimates than traditional trials (ratio of odds ratios 0.80, 95% confidence interval 0.70 to 0.91, I2=14%). Results were similar across various types of outcomes (mortality outcomes: 0.92, 0.74 to 1.15, I2=12%; non-mortality outcomes: 0.71, 0.60 to 0.84, I2=8%), data sources (electronic health records: 0.81, 0.59 to 1.11, I2=28%; registries: 0.86, 0.75 to 0.99, I2=20%; administrative data: 0.84, 0.72 to 0.99, I2=0%), and data quality (high data quality: 0.82, 0.72 to 0.93, I2=0%).

CONCLUSIONS

Randomised clinical trials using routinely collected data for outcome ascertainment show smaller treatment benefits than traditional trials not using routinely collected data. These differences could have implications for healthcare decision making and the application of real world evidence.

Patient registries for home oxygen research and evaluation

Randomized clinical trials are the preferred study design to address key research questions about the benefits or harms of interventions. However, randomized trials of oxygen therapy are difficult to conduct and have limitations. The purpose of this article is to offer our view on the potential use of patient registries in the field of home oxygen in COPD as an alternative to randomized trials by referring to the Swedish experience with a national registry for respiratory failure. Patient registries use 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. As opposed to administrative databases, patient registries serve one or more predetermined scientific, clinical, or policy purposes. By systematically and prospectively compiling relevant data, patient registries may describe the natural history of a disease, determine effectiveness and cost-effectiveness, assess safety or harm, and measure quality of care. Registry-based randomized trials (ie, randomized trials within a clinical registry) combine the advantages of a prospective randomized trial with the strengths of a large-scale all-comers clinical registry. Challenges and issues in the design and implementation of patient registries include the representativeness of participants, data collection, quality assurance, ownership, and governance. Notwithstanding their limitations, patient registries represent valuable tools in the conduct of research in the area of home oxygen therapy.