Pregnancy outcomes after exposure to interferon beta: a register-based cohort study among women with MS in Finland and Sweden.

BACKGROUND: Our aim was to estimate and compare the prevalence of adverse pregnancy outcomes among pregnant women with multiple sclerosis (MS) exposed to interferon beta (IFNB) and among women with MS unexposed to any MS disease-modifying drug (MSDMD). METHODS: This cohort study used Finnish (1996-2014) and Swedish (2005-2014) national register data. Women with MS having IFNB dispensed 6 months before or during pregnancy as the only medication were considered as IFNB exposed (only IFNB-exposed), whereas women with MS unexposed to any MSDMD were considered unexposed (MSDMD-unexposed). Prevalence was described and compared using log-binomial or logistic regression and adjusted for potential confounders including maternal age and comorbidity. RESULTS: Among 2831 pregnancies, 2.2% of the only IFNB-exposed and 4.0% of the MSDMD-unexposed women had serious adverse pregnancy outcomes [elective termination of pregnancy due to foetal anomaly (TOPFA), major congenital anomaly (MCA) in live, or stillbirth]. After adjustments, the prevalence of serious adverse pregnancy outcomes was lower among the only IFNB-exposed compared with the MSDMD-unexposed [relative risk 0.55, 95% confidence interval (CI) 0.31-0.96]. The prevalence of individual outcomes, including MCA, spontaneous abortions, and stillbirths was not increased with IFNB exposure. Women with MS exposed to IFNB appeared more likely to terminate their pregnancy for reasons other than foetal anomaly, compared with MSDMD-unexposed pregnant MS patients (odds ratio 1.71, 95% CI 1.06-2.78). CONCLUSION: In this large cohort study, no increase in the prevalence of adverse pregnancy outcomes was observed in women with MS exposed to IFNB compared with MS patients unexposed to any MSDMDs. This study together with other evidence led to a change in the labels of the IFNB products in September 2019 in the European Union, and IFNB use today may be considered during pregnancy, if clinically needed.

Prevalence and perceived preventability of self-reported adverse drug events--a population-based survey of 7099 adults.

PURPOSE: Adverse drug events (ADEs) are common and often preventable among inpatients, but self-reported ADEs have not been investigated in a representative sample of the general public. The objectives of this study were to estimate the 1-month prevalence of self-reported ADEs among the adult general public, and the perceived preventability of 2 ADE categories: adverse drug reactions (ADRs) and sub-therapeutic effects (STEs). METHODS: In this cross-sectional study, a postal survey was sent in October 2010 to a random sample of 13 931 Swedish residents aged ≥ 18 years. Self-reported ADEs experienced during the past month included ADRs, STEs, drug dependence, drug intoxications and morbidity due to drug-related untreated indication. ADEs could be associated with prescription, non-prescription or herbal drugs. The respondents estimated whether ADRs and STEs could have been prevented. ADE prevalences in age groups (18-44, 45-64, or ≥65 years) were compared. RESULTS: Of 7099 respondents (response rate 51.0%), ADEs were reported by 19.4% (95% confidence interval, 18.5-20.3%), and the prevalence did not differ by age group (p>0.05). The prevalences of self-reported ADRs, STEs, and morbidities due to drug-related untreated indications were 7.8% (7.2-8.4%), 7.6% (7.0-8.2%) and 8.1% (7.5-8.7%), respectively. The prevalence of self-reported drug dependence was 2.2% (1.9-2.6%), and drug intoxications 0.2% (0.1-0.3%). The respondents considered 19.2% (14.8-23.6%) of ADRs and STEs preventable. Although reported drugs varied between ADE categories, most ADEs were attributable to commonly dispensed drugs. Drugs reported for all and preventable events were similar. CONCLUSIONS: One-fifth of the adult general public across age groups reported ADEs during the past month, indicating a need for prevention strategies beyond hospitalised patients. For this, the underlying causes of ADEs should increasingly be investigated. The high burden of ADEs and preventable ADEs from widely used drugs across care settings supports redesigning a safer healthcare system to adequately tackle the problem.

Methods for assessing the preventability of adverse drug events: a systematic review.

BACKGROUND: Preventable adverse drug events (ADEs) are common in both outpatient and inpatient settings. However, the proportion of preventable ADEs varies considerably in different studies, even when conducted in the same setting, and methods for assessing the preventability of ADEs are diverse. OBJECTIVE: The aim of this article is to identify and systematically evaluate methods for assessing the preventability of ADEs. DATA SOURCES: Seven databases (Cochrane, CINAHL, EMBASE, IPA, MEDLINE, PsycINFO and Web of Science) were searched in September 2010 utilizing the databases' index terms and other common terminology on preventable ADEs. No limits for the years of publication were set. Reference lists of included original articles and relevant review articles were also screened. STUDY SELECTION: After applying predetermined inclusion and exclusion criteria on 4161 unique citations, 142 (3.4%) original research articles were included in the review. One additional article was included from reference lists. Outcome measures of included studies had to include the frequency of ADEs and the assessment of their preventability. Studies were excluded if they focused on individuals with one specific type of treatment, medical condition, medical procedure or ADE. DATA EXTRACTION: Measurement instruments for determining the preventability of ADEs in each article were extracted and unique instruments were compared. The process of assessing the preventability of ADEs was described based on reported actions taken to standardize and conduct the assessment, and on information about the reliability and validity of the assessment. DATA SYNTHESIS: Eighteen unique instruments for determining the preventability of ADEs were identified. They fell under the following four groups: (i) instruments using a definition of preventability only (n = 3); (ii) instruments with a definition of preventability and an assessment scale for determining preventability (n = 5); (iii) instruments with specific criteria for each preventability category (n = 3); and (iv) instruments with an algorithm for determining preventability (n = 7). Of actions to standardize the assessment process, performing a pilot study was reported in 21 (15%), and use of a standardized protocol was reported in 18 (13%), of the included 143 articles. Preventability was assessed by physicians in 86 (60%) articles and by pharmacists in 41 (29%) articles. In 29 (20%) articles, persons conducting the assessment were described as trained for or experienced in preventability assessment. In 94 (66%) articles, more than one person assessed the preventability of each case. Among these 94 articles, assessment was done independently in 73 (51%) articles. Procedures for managing conflicting assessments were diverse. The reliability of the preventability assessment was tested in 39 (27%) articles, and 16 (11%) articles referred to a previous reliability assessment. Reliability ranged from poor to excellent (kappa 0.19-0.98; overall agreement 26-97%). Four (3%) articles mentioned assessing validity, but no sensitivity or specificity analyses or negative or positive predictive values were presented. CONCLUSIONS: Instruments for assessing the preventability of ADEs vary from implicit instruments to explicit algorithms. There is limited evidence for the validity of the identified instruments, and instrument reliability varied significantly. The process of assessing the preventability of ADEs is also commonly imprecisely described, which hinders the interpretation and comparison of studies. For measuring the preventability of ADEs more accurately and precisely in future, we believe that existing instruments should be further studied and developed, or that one or more new instruments should be developed, and the validity and reliability of the existing and new instruments be established.