Ambulatory e-Prescribing: Evaluating a Novel Surveillance Data Source

Researchers have studied many potential sources of data for biosurveillance but have tended to focus on ambulatory visits and over-the-counter pharmaceutical sales. Data from electronic prescribing (e-prescribing) systems in an ambulatory setting have not been evaluated critically, but they may provide valuable data for surveillance. In this paper we evaluate the utility of e-prescribing data for surveillance of respiratory infections. Demographic data were analyzed to determine the differences between patients in an e-prescribing system and the general population. Correlation analysis was performed on the time-series for common respiratory tract antibiotics and the time-series for respiratory tract infection incidence. Demographic data showed a strong bias towards older people in the e-prescribing system when compared to the general population. The analysis also showed that a subset of antibiotics are highly correlated with respiratory tract indications (0.84, p<0.0001, 95% CI 0.73-0.90). The over-representation of higher age groups in the electronic prescribing system suggest that data from such systems may be suitable for observing trends in chronic conditions or infectious conditions more common in the elderly. The results also suggest that a set of antibiotics can be identified that reflect the incidence of respiratory tract infections.