Investigating patient narratives posted on Internet and their informativeness level for pharmacovigilance purpose: The example of comments about statins

Abstract

Health-related networks like patient health forums may be considered as potential sources of information to early detect pharmacovigilance issues or complete data on drug safety. However, the clinical and pharmacological relevancy of such a source has not been clearly explored. We aimed to describe the characteristics and the informativeness level of Internet narratives posted by patients and mentioning adverse drug reactions (ADRs) related to statins. A retrospective cross-sectional study was conducted on an Internet website dedicated to share experience on medicines. One day of December 2012, postings about simvastatin, rosuvastatin and atorvastatin publicly available on the website were collected. Their informativeness according to 16key elements of information (including drug start and stop date, duration of treatment, time to onset and duration of the ADR, outcome, medical history, concomitant medication) was assessed. General information about reported ADRs was also investigated. Among the 96postings related to statins, 72 (40women, 32men; mean age: 59 [40-78]) mentioned at least one ADR accounting for a total of 176ADRs. Musculoskeletal and connective tissue disorders (42.6%) and nervous system disorders (15.3%) were the main represented ADRs. Only 2patients mentioned ADRs that could be considered as serious but 24patients mentioned they stopped or switched their treatment toward another lipid modifying agent because of the ADR. Mean number of available key elements of information per narrative was 6/16. Time to onset and duration of the ADR were respectively available in only 31% and 3% of the narratives. Medical history and concomitant medication were respectively lacking in 87% and 86% of the narratives. Outcome was found only in 39% of the narratives. Patient narratives posted on Internet include mainly non-serious expected ADR. However, their informativeness level is very incomplete and makes difficult their assessment and use for pharmacovigilance purpose.