title: Impact of information letters on the reporting rate of adverse drug reactions and the quality of the reports: a randomized controlled study.
abstract: BACKGROUND
  Spontaneous reporting of adverse drug reactions (ADRs) is an important method for pharmacovigilance, but under-reporting and poor quality of reports are major limitations. The aim of this study was to evaluate if repeated one-page ADR information letters affect (i) the reporting rate of ADRs and (ii) the quality of the ADR reports.
  
  
  METHODS
  All 151 primary healthcare units in the Region Västra Götaland, Sweden, were randomly allocated (1:1) to an intervention (n = 77) or a control group (n = 74). The intervention consisted of one-page ADR information letters administered at three occasions during 2008 to all physicians and nurses in the intervention units. The number of ADR reports received from the 151 units was registered, as was the quality of the reports, which was defined as high if the ADR was to be reported according to Swedish regulations, that is, if the ADR was (i) serious, (ii) unexpected, and/or (iii) related to the use of new drugs and not labelled as common in the Summary of Product Characteristics. A questionnaire was administered to evaluate if the ADR information letter had reached the intended recipient.
  
  
  RESULTS
  Before the intervention, no significant differences in reporting rate or number of high quality reports could be detected between the randomization groups. In 2008, 79 reports were sent from 37 intervention units and 52 reports from 30 control units (mean number of reports per unit ± standard deviation: 1.0 ± 2.5 vs. 0.7 ± 1.2, P = 0.34). The number of high quality reports was higher in intervention units than in control units (37 vs. 15 reports, 0.5 ± 0.9 vs. 0.2 ± 0.6, P = 0.048). According to the returned questionnaires (n = 1,292, response rate 57%), more persons in the intervention than in the control group had received (29% vs. 19%, P < 0.0001) and read (31% vs. 26%, P < 0.0001) an ADR information letter.
  
  
  CONCLUSIONS
  This study suggests that repeated ADR information letters to physicians and nurses do not increase the ADR reporting rate, but may increase the number of high quality reports.
authors: Department of Clinical Pharmacology and Regional Pharmacovigilance Centre, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors: Marie-Louise
authors: ML
authors: Johansson
authors: Staffan
authors: S
authors: Hägg
authors: Susanna M
authors: SM
authors: Wallerstedt
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems / Q000458:organization & administration* / Q000592:standards; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D033181:Information Dissemination / Q000379:methods*; D009726:Nurses; D060735:Pharmacovigilance; D010820:Physicians; D011320:Primary Health Care; D012107:Research Design; D011795:Surveys and Questionnaires; D013548:Sweden