The phrase "ascertain data sources" is correct and usable in written English.
You can use it when discussing the process of identifying or determining the origins of data for research or analysis purposes.
Example: "Before starting the analysis, it is crucial to ascertain data sources to ensure the reliability of the findings."
Alternatives: "identify data sources" or "determine data sources".
Insulin titration could not be ascertained from data sources.
New cases occurring up until 31 December 2007 were ascertained by multiple data sources including self-report, linkage to primary or secondary care registers, linkage to pharmacy databases, medication use, hospital admissions, and mortality data.
Incident type 2 diabetes cases until 31 July 2006 were ascertained using multiple data sources, including self-report of doctor-diagnosed diabetes from the second health check or follow-up health and lifestyle questionnaires, self-report of diabetes-specific medication in either of the two follow-up questionnaires or medication brought to the follow-up health check.
New cases of diabetes occurring up until 31 December 2005 were ascertained using multiple data sources including: self-report of doctor-diagnosed diabetes on three follow-up health and lifestyle questionnaires, i.e., a positive response to the question "Has a doctor ever told you that you have diabetes?" or self-reported diabetes medication or diabetes medication brought to the follow-up visit.
New cases occurring up until 31 December 2007 were ascertained by using multiple data sources: self-report of doctor-diagnosed diabetes or diabetes-specific medication, linkage to primary or secondary care registers, linkage to pharmacy databases, hospital admissions data, or mortality data.
Data are linked to national death data sources to ascertain patients' vital status and underlying cause of death.
Further research is needed to identify the optimal method(s) to ascertain IBS cases in both data sources.
This limitation suggests that findings should be replicated using multiple data sources that ascertain cause of death information in various ways (e.g. Corti et al. 1999).
There are no accurate data sources to ascertain congenital anomalies in pregnancies than end in spontaneous abortion because many occur early in gestation when women may not know they are pregnant, and autopsy information on later losses is rarely ascertained.
After a comprehensive review of all data sources to ascertain possible exposure to asbestos outside of the diamond-mining industry, only six diamond miners with one or more asbestos-related diseases were included in the case series.
