Frequency and severity of adverse drug reactions due to self-medication: a cross-sectional multicentre survey in emergency departments.

BACKGROUND: Little is known about the relation of adverse drug reactions (ADRs) to self-use of medications. OBJECTIVE: The aim of this study was to determine the frequency and severity of ADRs related to self-medication (ADR-SM) among emergency department (ED) patients and to describe their main characteristics. METHODS: A prospective, cross-sectional, observational study was conducted over a period of 8 weeks (1 March to 20 April 2010), in the ED of 11 French academic hospitals. Adult patients presenting to the ED during randomization periods were included, with the exception of cases of self-drug poisoning, inability to complete self-medication questionnaire, or refusal. Clinical outcomes were assessed as well as history of self-medication behaviours and all drugs taken. All doubtful files and those related to ADR-SM were systematically reviewed by an expert committee. RESULTS: A total of 3,027 of 4,661 patients presenting to the ED met the inclusion criteria. Of these, 84.4 % declared a self-medication behaviour, 63.7 % took at least one non-prescribed drug during the previous 2 weeks and 59.9 % took a prescribed medication. A total of 296 patients experienced an ADR (9.78 %), of which 52 (1.72 %) were related to self-medication. Those ADRs related to self-medication included prescribed drugs (n = 19), non-prescribed drugs (n = 17), treatment discontinuation (n = 14), and interactions between non-prescribed and prescribed drugs (n = 2). The ADRs attributed to non-prescribed drugs represented 1 % of all patients taking non-prescribed drugs (n = 1,927). ADR severity was significantly lower for those related to self-medication (p = .032). CONCLUSION: Self-medication is frequent; its potential toxicity should not be neglected, taking into account the rate of adverse drug reactions in about 1 % of ED patient.

A questionnaire to document self-medication history in adult patients visiting emergency departments.

PURPOSE: To develop the first questionnaire to obtain a complete medication history by documenting self-medication history in adult patients admitted to a medical emergency department (ED). METHODS: A Questionnaire to document Self-Medicating Behaviours (QSMB) was developed between January and September 2008 (reference period), tested and refined between October and December 2008, and used routinely between January and December 2009 (routine period) in a tertiary care medical ED. The rate of SMBs measured with QSMB during the routine period was compared to the SMB rate measured with a spontaneous reporting method during the reference period. As survey teams changed every trimester, we also analysed the evolution of SMB rate over time. RESULTS: QSMB is divided into two parts. The first part consists of 20 closed-ended questions exploring all indications and dimensions of self-medication. The second part assesses the characteristics of each medication mentioned by the patient in the first 20 questions. The patients interviewed during reference and routine periods did not significantly differ. The routine period patients reported a third more SMBs (89.8% vs 57.6%, respectively; p < 0.0001) and twice more self-medication drugs than the reference period patients. SMB rate was significantly different between the survey teams during the reference period (p < 0.0001), but not during the routine period (p = 0.078). CONCLUSIONS: This questionnaire complements the traditional tools that are already available to collect medication histories of prescribed drugs. It may improve the recognition of iatrogenic conditions related to self-medication, and provide support to public health efforts and research programs on self-medication.

[Self-medicating behaviours in patients admitted to a medical emergency department]. / Étude des comportements d'automédication chez les patients admis dans un service d'urgences médicales.

OBJECTIVE: To describe the self-medicating behaviours (SMBs) in patients admitted to a tertiary care medical emergency department (ED); to study the factors associated with SMBs. METHODS: Observational cross-sectional study conducted in 2009. Included patients were interviewed about their SMBs using a standardized questionnaire. The search for factors associated with SMBs used multivariate logistic regression analysis. RESULTS: Among the 315 patients who were interviewed, 239 (75.9%) reported one SMBs or more in their lives and 105 (43.9%) within 7 days of admission to the ED. Some of the medications reported during interviews are known to be associated with adverse drug events. After adjustment, SMBs were conversely associated with an age ≥80 years, a number of prescribed medications ≥4 and a social vulnerability condition. CONCLUSION: The description of SMBs and the analysis of their determinants are necessary to improve the recognition of adverse events related to self-medication in ED patients.