Introduction
Moderate asthma exacerbations are symptom driven events which have been associated with poor outcomes and are not clearly recorded as part of EMR data.

Aims and objectives
To investigate the utility of UK primary care electronic medical record (EMR) data to identify moderate asthma exacerbations.

Methods
A retrospective cohort study of previous participants of the Salford Lung Studies pragmatic randomized controlled effectiveness trial, augmented via linkage to EMRs and patient-completed asthma questionnaires, including self-reported moderate exacerbations.

The following EMR events were considered potential moderate exacerbations: asthma exacerbation medical code, decreased lung function, or respiratory symptoms and with respiratory medication using within ±7 days. We also assessed three alternative algorithms by altering time period for respiratory medications and broadening diagnostic codes used.

The validity of EMR-derived versus self-reported moderate exacerbations was assessed.

Results
Of the 485 patients included (mean age: 56 yrs; 67% female), 420 reported having a moderate exacerbation in the prior year. Table 1 presents sensitivity and specificity of each EMR-derived algorithm.

Conclusions
Here we demonstrate the difficulty identifying moderate asthma exacerbations in EMR data. Improved structured recording of these events in primary care may improve research and clinical care.

Funding: GSK (214485)