Extracting epidemiological data from electronic medical record recording systems in United Kingdom primary care

Electronic medical records (EMRs) in primary care represent a longitudinal record of patient’s current and past history and important health related data. The ability to use of electronic medical records from a variety of different sources is an important and growing area of research. This study aims to use participants in an existing cohort of patients (the Gedling study) and extract their GP health data into a usable research database. The General Practitioners of each study participant were contacted and provided with evidence of consent to extract the records. The software packages in use at participating practices were examined to determine the most suitable format for data export, and the process documented. Various methods were considered to convert the extracted records into a research-suitable format, with the use of regular expressions being selected. Comparisons were made between the amount and type of data recorded among the software packages. The content of the converted medical records was compared with the information obtained directly from participants through the Gedling study surveys. There were notable differences across different GP software packages; particularly with regard to the amount of free text which is recorded in individual patient records with the most free text found in older patients, women and more deprived groups. There were some notable differences in the numbers of prescriptions and consultations recorded in each package. Self-reported asthma, wheeze, COPD cases, and hay fever recordings showed fair agreement with medical records. EMRs are increasingly the main mechanism used to record patient data and are fast becoming a large repository of clinical information. Exploring this potential it can contribute to our understanding of patient needs, prescribing patterns, accurate prevalence and incidence of disease and whether national policies for healthcare are delivering the benefits they set out to achieve