Applying Domain Knowledge for Data Quality Assessment in Dermatology

The Dermatology Clinic at the Clinical Center of Vojvodina, Novi Sad, Serbia, has actively collected data regarding patients' treatment, health insurance and examinations. These data were stored in documents in the comma-separated values (CSV) format. Since many fields in these documents were presented as free form text or allow null values, there are many data records that are inconsistent with the real-world system. Currently, there is a large need for an analytic system that can analyze these data and find relevant patterns. Since such an analytic system would require clean and accurate data, there is a need to assess data quality. Therefore, a data quality system should be designed and built with a goal of identifying inaccurate records so that they can be aligned with the real-world state. In our approach to data quality assessment, the domain knowledge about data is used to define rules which are then used to evaluate the quality of the data. In this paper, we present the architecture of a data quality system that is used to define and apply these rules. The rules are first defined by a domain expert and then applied to data in order to determine the number of records that do not match the defined rules and identify the exact anomalies in the given records. Also, we present a case study in which we applied this data quality system to the data collected by the Dermatology Clinic.