[Pharmacovigilance center --internal medicine interactions: A useful diagnostic tool]

Patients hospitalized in internal medicine often have unexplained clinical symptoms for which a drug origin can be considered. The prevalence of patients hospitalized for iatrogenic is estimated between 4-22%. We wanted to evaluate the diagnostic value of the regional center of pharmacovigilance to identify or confirm an iatrogenic disease in the department of internal medicine of Lille and characterize factors associated with drug-related side effect.

This is a single-center prospective diagnostic study. We included all subsequent requests from the department of internal medicine with the Nord-Pas-de-Calais regional pharmacovigilance center between 2010 and 2012. The opinion of the regional pharmacovigilance centre was held on the record of the adverse drug reaction in the national pharmacovigilance database and analyzed according to the conclusion of iatrogenic used by clinicians in internal medicine (reference diagnosis) with a follow-up to June 2013. The variables relating to the patient, medication and adverse events were analyzed by binary logistic regression.

We analyzed 160 contacts: 118 concordant cases, 38 false-positives (drug-related side effect retained by the regional pharmacovigilance center only), 4 false negatives. Registration in the national pharmacovigilance database had a sensitivity of 96% (95% CI [0.92 to 0.99]), a specificity of 46% (95% CI [0.38 to 0.53]), a value positive predictive of 69% (95% CI [0.62 to 0.76]), a negative predictive value of 89% (95% CI [0.84 to 0.94]) and a negative likelihood ratio of 0.1. False-positive had chronological and semiological accountabilities questionable (adjusted RR=2.1, 95% CI [1.2 to 2.8]).

In our study, the regional pharmacovigilance center confirms the clinician's suspicion of drug-related side effects and helps to exclude drug-induced with a high negative predictive value.