Background: Combining National Quality Registries (NQRs) with existing National Health Registries (NHRs) might make it possible to get a wider picture of older adults health situation. The aim was to examine the feasibility of aggregating data across different NQRs and existing NHRs to explore the possibility to investigate trajectories and patterns of disease and care, specifically for the most ill older adults.

Method: A Swedish twin population (N = 44,816) was linked to nine NQRs and four NHRs. A descriptive mixed-method study was performed. A manifest content analysis identified which health parameters were collected from each NQR. Factor analysis identified patterns in representation across NQRs. Two case studies illustrated individual trajectories of care by using NQRs and NHRs.

Results: About 36% of the population was registered in one or more NQRs. NQRs included 1849 variables that were sorted into 13 categories with extensive overlap across the NQRs. Health and function variables were identified, but few social or cognitive variables. Even though most individuals demonstrated unique patterns of multi-morbidities, factor analysis identified three clusters of representation in the NQRs with sufficient sample sizes for future investigations. The two cases illustrated the possibility of following patterns of disease and trajectories of care.

Conclusions: NQRs seem to be a significant source for collecting data about a population that may be underrepresented in most research on aging because of their age and poor health. However, NQRs are primarily disease related, and further development of the registries to maximize coverage and utility is needed.