If it doesn't already, the nationwide Register of Laboratory Results for Research should cover Central Denmark Region in the future, so we should design the function around that data structure (users supplementing with data from LABKA should preprocess it to match this structure).
Based on the functionality flow, this function filters diagnostic hemoglobin-a1c values from biomarker data.
https://github.com/steno-aarhus/osdc/blob/375e652fa27810feddb9e9cf53bc8673e2b43baa/vignettes/function-flow.Rmd#L78-L83
From @Aastedet 's original issue #8 :