Are prescribers not aware of cardiovascular contraindications for diclofenac? A claims data analysis

To compare diclofenac use before and after implementation of European risk minimization measures in 2013, focusing on diclofenac initiators and prevalence of congestive heart failure (NYHA class II-IV), ischaemic heart disease, peripheral arterial disease and cerebrovascular disease (new contraindications) in these patients in Germany.

We included adults with health insurance coverage on 1 January 2011 (cohort 2011) or 1 January 2014 (cohort 2014) and during a 1-year pre-observation period. We defined diclofenac initiators as persons filling a prescription of systemic diclofenac in 2011 (cohort 2011) or 2014 (cohort 2014) and without such a prescription during the respective pre-observation period.

Each cohort comprised >10 million persons. Between 2011 and 2014, the age-standardized proportion of persons initiating diclofenac decreased by 29% (from 8.2% to 5.8%) amongst female patients and by 26% (from 8.5% to 6.3%) amongst male patients; in the subgroup of persons with new contraindications, this proportion decreased by 33% (from 9.8% to 6.6%) amongst female patients and by 31% (from 10.0% to 6.7%) amongst male patients. Amongst diclofenac initiators, the proportion of those with new contraindications did not change between 2011 (12.0%) and 2014 (11.8%).

The overall decline of about 30% in diclofenac initiation between 2011 and 2014 was largely independent of the presence or absence of new contraindications. The proportion of diclofenac initiators with a new contraindication remained at a high level (more than one in ten patients), demonstrating the need for research at the prescriber level (e.g. interventional studies) and further measures to improve patient safety.