Table III.

Completeness and accuracy of the common dataset.

Common data set	Completeness (% missing)a			Accuracy
	Whole database	Calendar years 2010–2011	Calendar year 2012 (6 months)
	(110,841 records)	(27,114 records)	(9,913 records)
Gender	0.0	0.0	0.0	Data is collected consistently among data sources according to usual identification procedures
Date of birth	0.0	0.0	0.0	Data is collected consistently among data sources according to usual identification procedures
Region of residence	0.1	0.1	0.0	Data is collected consistently among data sources according to usual identification procedures
Diagnosis	0.0	0.0	0.0	Diagnoses are controlled and validated by the RRsb and their accuracy rely on the selection criteria for the centres to become FDC of the RD network
Date of diagnosis	1.0	--	--	Inconsistencies among regions on the identification of the relevant diagnostic event and diagnostic centre.
Centre of RD diagnosis	11.9	1.2	0.4	Inconsistencies among regions on the identification of the relevant diagnostic event and diagnostic centre. A centre may change name following reorganisation.
Vital status	ND	ND	ND c	Uncertainties in this variable depend on the fact that the data sources of RRsb may not be fully aware of the reason why patients are lost to follow up. In the future, date of decease will be collected from death registries: this will result in a systematic and precise, although delayed, appraisal of this condition.
Date of decease	ND	ND	ND	Expectedly good (when reported). In the future, date of decease will be collected from death registries: this will result in a systematic and precise, although delayed, appraisal of this condition.
Date of disease onset	46.4	57.1	81.4	Uncertainties in this variable depend on i) lack of patient’s recollection; ii) gradual appearance of unspecific symptoms over a long period. Symptoms could also not set on due to effective treatment following early diagnosis (e.g. following neonatal screening)
Orphan drug used	14.9	10.7	4.6	The name of the active substance is communicated, but no standard catalogue or coding is used.

^aData completeness is measured as the proportion (%) of records without the indication of the value of the variable; calendar years refer to the date of diagnosis;

^bRegional registry;

^cND = not determined