What can millions of laboratory test results tell us about the temporal aspect of data quality? Study of data spanning 17 years in a clinical data warehouse.

•Data quality is crucial for secondary use.•Laboratory data are exposed to non-biological influences causing changes in their distributions.•We propose a nomenclature of temporal patterns present in laboratory data collected from clinical data warehouses.•We provide an automated method to detect temporal patterns in laboratory data.•Temporal patterns can have an impact of secondary use, we explore solutions for data contextualization.•Temporal patterns can have an impact of secondary use (including on statistical analysis), we explore solutions for data contextualization.