Search tips
Search criteria

Results 1-9 (9)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
author:("hgg, Staffan")
1.  Medication errors related to transdermal opioid patches: lessons from a regional incident reporting system 
A few cases of adverse reactions linked to erroneous use of transdermal opioid patches have been reported in the literature. The aim of this study was to describe and characterize medication errors (MEs) associated with use of transdermal fentanyl and buprenorphine.
All events concerning transdermal opioid patches reported between 2004 and 2011 to a regional incident reporting system and assessed as MEs were scrutinized and characterized. MEs were defined as “a failure in the treatment process that leads to, or has the potential to lead to, harm to the patient”.
In the study 151 MEs were identified. The three most common error types were wrong administration time 67 (44%), wrong dose 34 (23%), and omission of dose 20 (13%). Of all MEs, 118 (78%) occurred in the administration stage of the medication process. Harm was reported in 26 (17%) of the included cases, of which 2 (1%) were regarded as serious harm (nausea/vomiting and respiratory depression). Pain was the most common adverse reaction reported.
Of the reported MEs related to transdermal fentanyl and buprenorphine, most occurred during administration. Improved routines to ascertain correct and timely administration and educational interventions to reduce MEs for these drugs are warranted.
PMCID: PMC4062292  PMID: 24912424
Transdermal patch; Opioids; Fentanyl; Buprenorphine; Medication errors; Incident reporting system
2.  Economic Impact of Adverse Drug Events – A Retrospective Population-Based Cohort Study of 4970 Adults 
PLoS ONE  2014;9(3):e92061.
The aim was to estimate the direct costs caused by ADEs, including costs for dispensed drugs, primary care, other outpatient care, and inpatient care, and to relate the direct costs caused by ADEs to the societal COI (direct and indirect costs), for patients with ADEs and for the entire study population.
We conducted a population-based observational retrospective cohort study of ADEs identified from medical records. From a random sample of 5025 adults in a Swedish county council, 4970 were included in the analyses. During a three-month study period in 2008, direct and indirect costs were estimated from resource use identified in the medical records and from register data on costs for resource use.
Among 596 patients with ADEs, the average direct costs per patient caused by ADEs were USD 444.9 [95% CI: 264.4 to 625.3], corresponding to USD 21 million per 100 000 adult inhabitants per year. Inpatient care accounted for 53.9% of all direct costs caused by ADEs. For patients with ADEs, the average societal cost of illness was USD 6235.0 [5442.8 to 7027.2], of which direct costs were USD 2830.1 [2260.7 to 3399.4] (45%), and indirect costs USD 3404.9 [2899.3 to 3910.4] (55%). The societal cost of illness was higher for patients with ADEs compared to other patients. ADEs caused 9.5% of all direct healthcare costs in the study population.
Healthcare costs for patients with ADEs are substantial across different settings; in primary care, other outpatient care and inpatient care. Hence the economic impact of ADEs will be underestimated in studies focusing on inpatient ADEs alone. Moreover, the high proportion of indirect costs in the societal COI for patients with ADEs suggests that the observed costs caused by ADEs would be even higher if including indirect costs. Additional studies are needed to identify interventions to prevent and manage ADEs.
PMCID: PMC3956863  PMID: 24637879
3.  Prevalence and Perceived Preventability of Self-Reported Adverse Drug Events – A Population-Based Survey of 7099 Adults 
PLoS ONE  2013;8(9):e73166.
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).
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.
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.
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.
PMCID: PMC3762841  PMID: 24023828
4.  The Impact of Duration of Treatment on Reported Time-to-Onset in Spontaneous Reporting Systems for Pharmacovigilance 
PLoS ONE  2013;8(7):e68938.
Within pharmacovigilance, knowledge of time-to-onset (time from start of drug administration to onset of reaction) is important in causality assessment of drugs and suspected adverse drug reactions (ADRs) and may indicate pharmacological mechanisms involved. It has been suggested that time-to-onset from individual case reports can be used for detection of safety signals. However, some ADRs only occur during treatment, while those that do occur later are less likely to be reported. The aim of this study was to investigate the impact of treatment duration on the reported time-to-onset. Case reports from the WHO Global ICSR database, VigiBase, up until February 5th 2010 were the basis of this study. To examine the effect of duration of treatment on reported time-to-onset, angioedema and hepatitis were selected to represent short and long latency ADRs, respectively. The reported time-to-onset for each of these ADRs was contrasted for a set of drugs expected to be used short- or long-term, respectively. The study included 2,980 unique reports for angioedema and 1,159 for hepatitis. Median reported time-to-onset for angioedema in short-term treatments ranged 0-1 days (median 0.5), for angioedema in long-term treatments 0-26 days (median 8), for hepatitis in short-term treatments 4-12 days (median 7.5) and for hepatitis in long term treatments 19-73 days (median 28). Short-term treatments presented significantly shorter reported time-to-onset than long-term treatments. Of note is that reported time-to-onset for angioedema for long-term treatments (median value of medians being 8 days) was very similar to that of hepatitis for short-term treatments (median value of medians equal 7.5 days). The expected duration of treatment needs to be considered in the interpretation of reported time-to-onset and should be accounted for in signal detection method development and case evaluation.
PMCID: PMC3711907  PMID: 23869234
5.  Percentage of Patients with Preventable Adverse Drug Reactions and Preventability of Adverse Drug Reactions – A Meta-Analysis 
PLoS ONE  2012;7(3):e33236.
Numerous observational studies suggest that preventable adverse drug reactions are a significant burden in healthcare, but no meta-analysis using a standardised definition for adverse drug reactions exists. The aim of the study was to estimate the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions in adult outpatients and inpatients.
Studies were identified through searching Cochrane, CINAHL, EMBASE, IPA, Medline, PsycINFO and Web of Science in September 2010, and by hand searching the reference lists of identified papers. Original peer-reviewed research articles in English that defined adverse drug reactions according to WHO’s or similar definition and assessed preventability were included. Disease or treatment specific studies were excluded. Meta-analysis on the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions was conducted.
Data were analysed from 16 original studies on outpatients with 48797 emergency visits or hospital admissions and from 8 studies involving 24128 inpatients. No studies in primary care were identified. Among adult outpatients, 2.0% (95% confidence interval (CI): 1.2–3.2%) had preventable adverse drug reactions and 52% (95% CI: 42–62%) of adverse drug reactions were preventable. Among inpatients, 1.6% (95% CI: 0.1–51%) had preventable adverse drug reactions and 45% (95% CI: 33–58%) of adverse drug reactions were preventable.
This meta-analysis corroborates that preventable adverse drug reactions are a significant burden to healthcare among adult outpatients. Among both outpatients and inpatients, approximately half of adverse drug reactions are preventable, demonstrating that further evidence on prevention strategies is required. The percentage of patients with preventable adverse drug reactions among inpatients and in primary care is largely unknown and should be investigated in future research.
PMCID: PMC3305295  PMID: 22438900
6.  Impact of information letters on the reporting rate of adverse drug reactions and the quality of the reports: a randomized controlled study 
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.
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.
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.
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.
PMCID: PMC3182972  PMID: 21899766
7.  Antihypertensive drugs and erectile dysfunction as seen in spontaneous reports, with focus on angiotensin II type 1 receptor blockers 
To describe spontaneously reported cases of erectile dysfunction (ED) in association with angiotensin II type I blockers (ARB) and other antihypertensive drugs.
Subjects and methods:
All spontaneously reported cases of ED submitted to the Swedish Medical Products Agency (MPA) between 1990 and 2006, where at least one antihypertensive drug was the suspected agent, were scrutinized. Patient demographics, drug treatment and adverse reactions were recorded. Using the Bayesian Confidence Propagation Neural Network (BCPNN) method, the information component (IC) was calculated.
Among a total of 225 reports of ED, 59 involved antihypertensive drugs including ARB (9 cases) as suspected agents. A positive IC value was found indicating that ED was reported more often in association with antihypertensive drugs classes, except for angiotensin-converting enzyme inhibitors, compared with all other drugs in the database. Positive dechallenge was reported in 43 cases (72%).
All classes of major antihypertensive drugs including ARB were implicated as suspected agents in cases of ED. Few risk factors were identified. The relatively high reporting of ED in association with ARB is in contrast with previous studies, suggesting that ARB have neither a positive nor any effect on ED. This discrepancy suggests that further studies are warrnted on this potential adverse reaction to ARB.
PMCID: PMC3108714  PMID: 21701615
adverse drug reaction; spontaneous reporting; antihypertensive drugs; angiotensin II type 1 receptor blockers; erectile dysfunction
8.  Antipsychotics and risk of venous thromboembolism: A population-based case-control study 
Clinical epidemiology  2009;1:19-26.
During the last decade, the risk of venous thromboembolism (VTE) has been reported in users of antipsychotic drugs. However, the reports have been inconclusive. This study aimed to determine the relative risk of VTE in antipsychotic drug users. Using data from medical databases in North Jutland and Aarhus Counties, Denmark, and the Danish Civil Registration System, we identified 5,999 cases with a first-time diagnosis of VTE and, based on risk set sampling, 59,990 sex- and age-matched population controls during 1997–2005. Users of antipsychotic drugs were identified from population-based prescription databases and categorized based on filled prescriptions prior to admission date for VTE or index date for controls as current (at least one prescription within 90 days), recent (at least one prescription within 91–180 days), former (at least one prescription within 181–365 days) or nonusers (no recorded prescription within 365 days). Compared with nonusers, current users of any antipsychotic drugs had an increased risk of VTE (adjusted relative risk [ARR]: 1.99, 95% confidence interval [CI]: 1.69–2.34). Former users of any antipsychotic drugs had a nonsignificant elevated risk of VTE compared with nonusers (ARR: 1.54, 95% CI: 0.99–2.40, p-value: 0.056). In conclusion, users of antipsychotic drugs have an increased risk of VTE, compared with nonusers, which might be due to the treatment itself, to lifestyle factors, to the underlying disease, or to residual confounding.
PMCID: PMC2943162  PMID: 20865083
antipsychotic agents; venous thromboembolism; adverse effects; case-control study
9.  Fatal drug poisonings in a Swedish general population 
Pharmaceutical drug poisonings have previously been reported using single sources of information, either hospital data or forensic data, which might not reveal the true incidence. We therefore aimed to estimate the incidence of suspected fatal drug poisonings, defined as poisonings by pharmaceutical agents, by using all relevant case records from various sources in a Swedish population.
Every seventh randomly selected deceased in three counties in southeastern Sweden during a one-year period was identified in the Cause of Death Register. Relevant case records (death certificates, files from hospitals and/or primary care centres and medico-legal files) were reviewed for all study subjects.
Of 1574 deceased study subjects, 12 cases were classified as pharmaceutical drug poisonings according to the death certificates and 10 according to the medico-legal files. When reviewing all available data sources, 9 subjects (0.57%; 95% confidence interval: 0.20–0.94%) were classified as drug poisonings, corresponding to an incidence of 6.5 (95% confidence interval: 2.3–10.7) per 100 000 person-years in the general population. The drug groups most often implicated were benzodiazepines (33%), antihistamines (33%) and analgesics (22%).
Fatal drug poisonings is a relatively common cause of death in Sweden. By using multiple sources of information when investigating the proportion of fatal poisonings in a population, more accurate estimates may be obtained.
PMCID: PMC2679715  PMID: 19397805

Results 1-9 (9)