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Table 4 Missing data for select ascertainment and diagnosis among participants with complete minimum dataset information (n = 764)

From: Evaluation of the quality of clinical data collection for a pan-Canadian cohort of children affected by inherited metabolic diseases: lessons learned from the Canadian Inherited Metabolic Diseases Research Network

IMDAscertainment and diagnostic workup variables% missing
Across all CIMDRN-targeted diseasesAscertainment method (e.g., by NBS, family history, etc.)0%
Number of visits to metabolic clinic to determine diagnosis9%
Age at diagnosis9%
Centre where diagnosis was established0%
For those not ascertained by NBS (n = 138), was a NBS test done?a50%
For those ascertained by NBS (n = 626), was the NBS test positive for the diagnosed disease?a1%
For those whose NBS test was positive (n = 620), date of NBS test positive/referrala9%
For those diagnosed symptomatically (n = 125), age at first symptoma17%
For those diagnosed symptomatically (n = 125), presenting symptomsa0%
Diagnostic tests considered universally important
 PAH deficiency (n = 215)Plasma amino acid profile2%
 MCAD deficiency (n = 127)Acylcarnitine profile10%
 VLCAD deficiency (n = 33)Acylcarnitine profile< 10%
 MPS type I (n = 18)α-L-iduronidase activity< 10%
  1. IMD inherited metabolic disease, NBS newborn screening, PAH phenylalanine hydroxylase, MCAD medium-chain acyl CoA dehydrogenase, VLCAD very long-chain acyl-CoA dehydrogenase, MPS mucopolysaccharidosis
  2. adenominators for these data elements vary as not all variables were applicable to every participant