UCL Institute of Health Informatics


Antibiotic prescribing before and after the diagnosis of comorbidity

24 October 2019

Antibiotic prescribing before and after the diagnosis of co-morbidity: a cohort study using primary care electronic health records published by Clinical Infectious Diseases.

Figure from the paper showing the patterns of antibiotic use leading up to and after the diagnosis of diabetes, heart failure, Peripheral artery disease, stroke and the control group

Comorbidities like diabetes or Chronic Obstructive Pulmonary Disease (COPD) increase patients’ susceptibility to infections, but it is unclear how the onset of comorbidity impacts antibiotic use. A group of researchers led by Patrick Rockenschaub,a PhD student at the UCL IHI, aimed to estimate rates of antibiotic use before and after diagnosis of comorbidity in primary care to identify opportunities for antibiotic stewardship.

They analysed UK primary care records from the Clinical Practice Research Datalink (CPRD) database and included adults registered between 2008-2015 without prior comorbidity diagnoses . Monthly adjusted rates of antibiotic prescribing were estimated for patients with new-onset stroke, coronary heart disease, heart failure, peripheral arterial disease, asthma, chronic kidney disease, diabetes or COPD in the 12 months before and after diagnosis, and for controls without comorbidity.

The group found that antibiotic prescribing increased by 1.9-2.3 fold in the 4-9 months preceding diagnosis of conditions presenting with respiratory symptoms (COPD, heart failure, asthma)  before declining to stable levels within 2 months after diagnosis. Prescribing rates for patients with vascular conditions increased immediately before diagnosis and remained 30-39% higher than baseline afterwards. Rates of prescribing to controls increased by 17-28% in the months just before and after consultation.

The group's findings suggest that the onset of respiratory symptoms may be misdiagnosed as infection and that earlier diagnosis of these comorbidities could reduce avoidable antibiotic prescribing.

To read the full paper visit the Clinical Infectious Diseases website.

The paper's full citation is: Patrick Rockenschaub, Andrew Hayward, Laura Shallcross, Antibiotic prescribing before and after the diagnosis of comorbidity: a cohort study using primary care electronic health records, Clinical Infectious Diseases, , ciz1016, https://doi.org/10.1093/cid/ciz1016