Subjects
Subjects were identified at 9 hospitals serving approx. 4,575,000 people
by interrogating laboratory databases to identify individuals in three
specific age bands with reduced eGFR calculated using the Modified Diet
in Renal Disease (MDRD; 4 variable) or chronic kidney disease
epidemiology (CKDEPI) equations. Thresholds were chosen empirically by
estimating a feasible population size that could be sampled based on the
distribution of eGFR results in a sample of data from Queen’s Hospital,
Burton.
- Age 20-49, eGFR 15-54 mL/min/1.83m2
- Age 50-59, eGFR 15-49 mL/min/1.83m2
- Age 60-69, eGFR 15-39 ml/min/1.83m2
Laboratory database searches were performed using creatinine
measurements over a maximum a 6-year time period interval limited by
site-specific data access issues. Once provisionally identified,
subjects were invited to take part in the study as they had been
identified as having abnormal results in routine pathology testing. They
were asked if they would meet with a research nurse to allow collection
of a blood sample for lysosomal α-galactosidase activity. At the
research visit, patients provided informed consent, and basic
demographic details were collected. An EDTA blood sample was collected
and single drops were spotted on a dried blood spot (DBS) collection
card. Subjects indicated their preference for anonymity or if they
wanted to receive a copy of their results.