Hair cortisol and inhaled corticosteroid use in asthmatic children

BACKGROUND

Adrenal suppression is a side effect of long-term use of inhaled corticosteroids (ICS). Hair cortisol concentration (HCC) measurement is a noninvasive tool for measuring adrenal function that may be useful for asthmatic patients who are on long-term ICS treatment. The aim of this study was to compare HCC between children with and without asthma and to explore the association between HCC and ICS dose in asthmatic children.

METHODS

A cross-sectional observational study in subjects with or without asthma (n = 72 and 226, respectively, age 6-21 years). Hair samples were obtained from the posterior vertex for each subject and data on medication use were collected using questionnaires. HCC was analyzed by liquid chromatography-mass spectrometry in the most proximal 3 cm of hair.

RESULTS

Median HCC was significantly lower in subjects with asthma than in subjects without asthma: 1.83 pg/mg and 2.39 pg/mg, respectively (P value after adjustment for age, sex, and body mass index: .036). Median HCC was 1.98 pg/mg in asthmatics using no ICS, 1.84 pg/mg in those using a low dose, 1.75 pg/mg in those on a medium dose, and 1.46 in those using a high ICS dose (P = .54).

CONCLUSION

We observed a significantly lower HCC in asthmatics than in healthy controls and a nonsignificant trend of lower HCC with increasing ICS dose. Whether HCC measurement may be used to detect individuals at risk for hypocortisolism and may be useful to monitor adrenal function in asthmatic children using ICS needs to be further investigated.

EU postmarket surveillance plans for medical devices

Purpose

Recent public health safety issues involving medical devices have led to a growing demand to improve the current passive‐reactive postmarket surveillance (PMS) system. Various European Union (EU) national competent authorities have started to focus on strengthening the postmarket risk evaluation. As a consequence, the new EU medical device regulation was published; it includes the concept of a PMS Plan.

Methods

This publication reviewed Annex III Technical Documentation on PMS and Annex XIV Part B: Postmarket clinical follow‐up from the new Regulation (EU) 2017/745 of the European Parliament and of the Council on medical devices.

Results

The results of the PMS activities will be described in the PMS plan and will be used to update other related documents. A modular approach to structure the contents of the PMS plan will help to consistently update other PMS information. It is our suggestion that the PMS plan should consist of a PMS plan Core and a PMS plan Supplement. The PMS plan Core document will describe the PMS system, and the PMS plan Supplement will outline the specific activities performed by the manufacturer for a particular medical device.

Conclusions

The PMS plan may serve as a thorough tool for the benefit‐risk evaluation of medical devices. If properly developed and implemented, it will function as a key player in the establishment of a new framework for proactive safety evaluation of medical devices.

Generating and evaluating a propensity model using textual features from electronic medical records

Background

Propensity score (PS) methods are commonly used to control for confounding in comparative effectiveness studies. Electronic health records (EHRs) contain much unstructured data that could be used as proxies for potential confounding factors. The goal of this study was to assess whether the unstructured information can also be used to construct PS models that would allow to properly deal with confounding. We used an example of coxibs (Cox-2 inhibitors) vs. traditional NSAIDs and the risk of upper gastro-intestinal bleeding as example, since this association is often confounded due to channeling of coxibs to patients at higher risk of upper gastro-intestinal bleeding.

Methods

In a cohort study of new users of nonsteroidal anti-inflammatory drugs (NSAIDs) from the Dutch Integrated Primary Care Information (IPCI) database, we identified all patients who experienced an upper gastrointestinal bleeding (UGIB). We used a large-scale regularized regression to fit two PS models using all structured and unstructured information in the EHR. We calculated hazard ratios (HRs) to estimate the risk of UGIB among selective cyclo-oxygenase-2 (COX-2) inhibitor users compared to nonselective NSAID (nsNSAID) users.

Results

The crude hazard ratio of UGIB for COX-2 inhibitors compared to nsNSAIDs was 0.50 (95% confidence interval 0.18–1.36). Matching only on age resulted in an HR of 0.36 (0.11–1.16), and of 0.35 (0.11–1.11) when further adjusted for sex. Matching on PS only, the first model yielded an HR of 0.42 (0.13–1.38), which reduced to 0.35 (0.96–1.25) when adjusted for age and sex. The second model resulted in an HR of 0.42 (0.13–1.39), which dropped to 0.31 (0.09–1.08) after adjustment for age and sex.

Conclusions

PS models can be created using unstructured information in EHRs. An incremental benefit was observed by matching on PS over traditional matching and adjustment for covariates.

Antibiotic use in children with asthma: cohort study in UK and Dutch primary care databases

OBJECTIVES

To compare the rate, indications and type of antibiotic prescriptions in children with and without asthma.

DESIGN

A retrospective cohort study.

SETTING

Two population-based primary care databases: Integrated Primary Care Information database (IPCI; the Netherlands) and The Health Improvement Network (THIN; the UK).

PARTICIPANTS

Children aged 5-18 years were included from January 2000 to December 2014. A child was categorised as having asthma if there were ≥2 prescriptions of respiratory drugs in the year following a code for asthma. Children were labelled as non-asthmatic if no asthma code was recorded in the patient file.

MAIN OUTCOME MEASURES

Rate of antibiotic prescriptions, related indications and type of antibiotic drugs.

RESULTS

The cohorts in IPCI and THIN consisted of 946 143 and 7 241 271 person years (PY), respectively. In both cohorts, antibiotic use was significantly higher in asthmatic children (IPCI: 197vs126 users/1000 PY, THIN: 374vs250 users/1000 PY). In children with asthma, part of antibiotic prescriptions were for an asthma exacerbation only (IPCI: 14%, THIN: 4%) and prescriptions were more often due to lower respiratory tract infections then in non-asthmatic children (IPCI: 18%vs13%, THIN: 21%vs12%). Drug type and quality indicators depended more on age, gender and database than on asthma status.

CONCLUSIONS

Use of antibiotics was higher in asthmatic children compared with non-asthmatic children. This was mostly due to diseases for which antibiotics are normally not indicated according to guidelines. Further awareness among physicians and patients is needed to minimise antibiotic overuse and limit antibiotic resistance.

Impact and longevity of measles-associated immune suppression: a matched cohort study using data from the THIN general practice database in the UK

OBJECTIVE

To test the hypothesis that measles infection increases the incidence of non-measles infectious diseases over a prolonged period of time.

DESIGN

A population-based matched cohort study.

DATA SOURCES

This study examined children aged 1-15 years in The Health Improvement Network UK general practice medical records database. Participants included 2228 patients diagnosed with measles between 1990 and 2014, which were matched on age, sex, general practitioner practice and calendar year with 19 930 children without measles. All controls had received at least one measles vaccination. Children with a history of immune-compromising conditions or with immune-suppressive treatment were excluded.

PRIMARY OUTCOME MEASURES

Incidence rate ratio (IRR) of infections, anti-infective prescriptions and all-cause hospitalisations following measles in predetermined periods using multivariate analysis to adjust for confounding variables.

RESULTS

In children with measles, the incidence rate for non-measles infectious disease was significantly increased in each time period assessed up to 5 years postmeasles: 43% in the first month (IRR: 1.43; 95% CI 1.22 to 1.68), 22% from month one to the first year (IRR: 1.22; 95% CI 1.14 to 1.31), 10% from year 1 to 2.5 years (IRR: 1.10; 95% CI 1.02 to 1.19) and 15% (IRR: 1.15; 95% CI 1.06 to 1.25) in years 2.5 to 5 years of follow-up. Children with measles were more than three times as likely to receive an anti-infective prescription in the first month and 15%-24% more likely between the first month and 5 years. The rate of hospitalisation in children with measles was increased only in the month following diagnosis but not thereafter (IRR: 2.83; 95% CI 1.72 to 4.67).

CONCLUSION

Following measles, children had increased rates of diagnosed infections, requiring increased prescribing of antimicrobial therapies. This population-based matched cohort study supports the hypothesis that measles has a prolonged impact on host resistance to non-measles infectious diseases.

Risk of acute myocardial infarction during use of individual NSAIDs: A nested case-control study from the SOS project

BACKGROUND

Use of selective COX-2 non-steroidal anti-inflammatory drugs (NSAIDs) (coxibs) has been associated with an increased risk of acute myocardial infarction (AMI). However, the risk of AMI has only been studied for very few NSAIDs that are frequently used.

OBJECTIVES

To estimate the risk of AMI for individual NSAIDs.

METHODS

A nested case-control study was performed from a cohort of new NSAID users ≥18 years (1999-2011) matching cases to a maximum of 100 controls on database, sex, age, and calendar time. Data were retrieved from six healthcare databases. Adjusted odds ratios (ORs) of current use of individual NSAIDs compared to past use were estimated per database. Pooling was done by two-stage pooling using a random effects model (ORmeta) and by one-stage pooling (ORpool).

RESULTS

Among 8.5 million new NSAID users, 79,553 AMI cases were identified. The risk was elevated for current use of ketorolac (ORmeta 2.06;95%CI 1.83-2.32, ORpool 1.80; 1.49-2.18) followed, in descending order of point estimate, by indometacin, etoricoxib, rofecoxib, diclofenac, fixed combination of diclofenac with misoprostol, piroxicam, ibuprofen, naproxen, celecoxib, meloxicam, nimesulide and ketoprofen (ORmeta 1.12; 1.03-1.22, ORpool 1.00;0.86-1.16). Higher doses showed higher risk estimates than lower doses.

CONCLUSIONS

The relative risk estimates of AMI differed slightly between 28 individual NSAIDs. The relative risk was highest for ketorolac and was correlated with COX-2 potency, but not restricted to coxibs.

Comparing drug effectiveness in children: A systematic review

PURPOSE

The purpose of the study is to assess the current state of the art in pediatric comparative effectiveness research, potential gaps, and areas for improvement.

METHODS

Relevant articles from inception to February 2015 were retrieved from Embase and Medline. We sequentially screened titles, abstracts, and full texts, with independent validation. Data regarding general information and study methods including statistical analysis were extracted. Study quality was assessed using Newcastle-Ottawa Scale (NOS). Investigated drugs were ranked and compared with data on the prevalence of pediatric drug use.

RESULTS

Three thousand nine hundred twenty-six abstracts were screened for eligibility and inclusion, and 164 articles were included in the review. Most studies were from North America (46.7%). Only 78 studies (47.6%) reported the design: 90.8% were cohort studies. Neonates were least frequently investigated. The drugs that were most often studied included systemic antibacterials (11.4%), psycholeptics (7.9%), and antiepileptics (7.6%). Adjustment for confounding was made using propensity scores in 8.5% of the studies. Studies that did not report the design were of lower quality. Many effectiveness studies were done on antineoplastic agents, which are not frequently used and few studies on analgesics and drugs for obstructive airway diseases which are frequently prescribed.

CONCLUSIONS

There is ample opportunity to improve comparative effectiveness research for drugs used in pediatrics. Routinely prescribed drugs were seldom investigated. Modern methods for confounding adjustment, such as propensity scores, were rarely used.

Impact of different assumptions on estimates of childhood diseases obtained from health care data: A retrospective cohort study

Purpose

Accurate estimates of disease incidence in children are required to support pediatric drug development. Analysis of electronic health care records (EHR) may yield such estimates but pediatric‐specific methods are lacking. We aimed to understand the impact of assumptions regarding duration of disease episode and length of run‐in period on incidence estimates from EHRs.

Methods

Children aged 0 to 17 years (5–17 years for asthma) registered in the Integrated Primary Care Information database between 2002 and 2014 were studied. We tested the impact of the following: maximum duration of disease episode (0, 14, 30, 60, and 90 days) on recurrent diseases (acute otitis media [common] and acute pyelonephritis [rare]); and database run‐in period on chronic diseases—asthma (common) and type 1 diabetes (DM) (rare). We calculated incidence rate ratios with 95% confidence intervals and stratified using 1‐year age categories.

Results

Altogether, 503 495 children were registered. The incidence of acute otitis media was highest in <2‐year‐old children; using 30 days disease duration as reference, the rate increased with 8% if the duration was 14 days and decreased with 8% when extended to 60 days. Disease duration did not impact acute pyelonephritis (rare). No run‐in (to exclude prevalent cases) versus 24‐month run‐in period overestimated the incidence rate for asthma and DM by a factor of 2.

Conclusions

Analysis of EHR allows for estimation of disease incidence in children, but assumptions regarding episode length and run‐in period impact the incidence estimates. Such assumptions may be routinely explored.

Choice of time period to identify confounders for propensity score matching, affected the estimate: a retrospective cohort study of drug effectiveness in asthmatic children

OBJECTIVES

To control for confounding by indication in comparative (drug) effectiveness studies, propensity score (PS) methods may be used. Since childhood diseases or outcomes often present as acute events, we compared the effect of using different look-back periods in electronic health-care data, to construct PSs. This was applied in our research on the effect of a combination of inhaled corticosteroids/long-acting beta-2 agonists (ICS + LABA), either as fixed combination or used as loose combination (2 separate inhaler devices) in the prevention of severe asthma exacerbations.

METHODS

We created a cohort of children (5-17 years) diagnosed with asthma from the Dutch Integrated Primary Care information database. Within this cohort, we identified new users of ICS + LABA, either as fixed combination or loose combination (2 separate inhaler devices). The outcome of interest was severe asthma exacerbations. PSs for type of treatment were created using comorbidity and drug use history in different time windows: 1 week, 1 month, 3 months, 1 year, and full history prior to the start of treatment. PSs were used for matching subjects in both exposure groups. Time to first asthma exacerbation was analyzed with Cox proportional hazard regression. The results were compared with published clinical trials.

RESULTS

Of 39,682 asthmatic children, 3,500 (8.8%) were new users of either ICS + LABA fixed (3,324 [95.0%]) or loose (176 [5.0%]). The crude hazard ratio (HR) for a severe asthma exacerbation, comparing ICS + LABA fixed to loose was 0.37 (95% confidence interval [CI]: 0.20-0.66). PS-matched HRs (1 week, 1 month, 3 month, 1 year, and full history) were 0.48 (95% CI: 0.22-1.04); 0.60 (95% CI: 0.26-1.38), 0.69 (95% CI: 0.31-1.57), 0.56 (CI: 0.25-1.24), and 0.58 (CI: 0.24-1.36), respectively.

CONCLUSIONS

PS matching can be used to control for confounding in pediatric comparative (drug) effectiveness studies, the impact of different look-back periods to implement the PS is important. Controlling for confounders occurring in the 3 months preceding drug exposure may yield results comparable to clinical trial results.

Is patient exposure preapproval and postapproval a determinant of the timing and frequency of occurrence of safety issues?

BACKGROUND

The amount of drug exposure, pre and post approval, is considered to be a direct determinant of knowledge about the safety of a drug. A larger pre-approval exposed population is supposed to reduce the risk of unanticipated safety issues post-approval. The amount of use in the postapproval population is also expected to influence the occurrence and timing of safety issues. We investigated how the amount of pre and post approval exposure influences the detection of post-approval safety issues.

METHODS

A cohort of innovative drugs approved in Europe was followed for the period of 2012-2016. The main outcome of interest was a new safety issue in the period. Post-approval exposure was collected at 6 month intervals, and pre-approval exposure was collected at the moment of authorisation. Other characteristics collected for the included drugs were anatomical therapeutical chemical (ATC) class, biological status, orphan status and type of approval. We used Cox proportional hazards regression to investigate the association between exposure and the hazard of having a first safety issue.

RESULTS

The pre-approval exposure was not associated with the risk of safety issues after adjusting for ATC class, biological status, and treatment duration. Higher post-approval exposure was associated with more new safety issues identified (HR = 2.44 (95% CI = 1.12-5.31)) for drugs with more than 1,000 patient-years of cumulative exposure compared to drugs with less than 1,000 patient years of exposure.

CONCLUSION

Our results suggest that postapproval exposure influences the detection of safety issues.

Antibiotic-Induced Liver Injury in Paediatric Outpatients: A Case-Control Study in Primary Care Databases

Introduction

Antibiotics are the most commonly prescribed drug class in children. Real-world data mining on the paediatric population showed potential associations between antibiotic use and acute liver injury.

Objective

We assessed risk estimates of liver injury associated with antibiotic use in children and adolescent outpatients.

Methods

A large, multi-database, population-based, case-control study was performed in people <18 years of age from two European countries (Italy and The Netherlands) during the period 2000–2008. All potential cases of liver injury were automatically extracted from three databases and then manually validated based on Council for International Organizations of Medical Sciences (CIOMS) criteria and by exclusion of all competing causes for liver injury. Up to 100 control participants were sampled for each case and were matched on index date of the event, age, sex and database. Based on prescription data, antibiotic exposure was categorized as current, recent or past use by calculating the time period between the end of prescription and the index date. Multivariate conditional logistic regression analyses were applied to calculate odds ratios (ORs) as a measure of the association (with 95% confidence interval [CI]).

Results

We identified 938 cases of liver injury and matched to 93,665 controls. Current use of overall antibiotics is associated with a threefold increased risk of liver injury compared with past use (adjusted OR [OR_adj] 3.22, 95% CI 2.57–4.03). With regard to individual antibiotics, the risk is significantly increased for current use of each antibiotic (p < 0.005), except for azithromycin. Risk estimates vary from the lowest OR_adj of 1.86 (95% CI 1.08–3.21) for amoxicillin to the highest OR_adj of 24.16 (95% CI 11.78–49.54) for cotrimoxazole (i.e. sulphamethoxazole/trimethoprim) and 26.70 (95% CI 12.09–58.96) for ceftriaxone. Sensitivity analyses confirm the associations for ceftriaxone, cotrimoxazole, and clarithromycin.

Conclusion

Antibiotic-induced liver injury in children is heterogeneous across the use of individual antibiotics. When prescribing ceftriaxone, cotrimoxazole and clarithromycin in children, paediatricians should definitely be aware of their potential risk of liver injury, even if for short periods.

Electronic supplementary material

The online version of this article (doi:10.1007/s40264-016-0493-y) contains supplementary material, which is available to authorized users.

Prenatal antidepressant exposure and the risk of attention-deficit hyperactivity disorder in children: A systematic review and meta-analysis

This systematic review assesses the association between prenatal antidepressant exposure and risk of ADHD in children. Electronic databases were searched up to 25 July 2017. Observational studies examining this association were included in the review and meta-analysis was conducted where appropriate. Eight relevant studies were identified. The seven studies included in the meta-analysis comprised a total of 2,886,502 children. The pooled estimates comparing prenatal exposure to non-exposure showed an adjusted rate ratio (aRR) of 1.39 (95%CI 1.21-1.61). Similarly, an increased risk was found comparing previous antidepressant users and non-users: aRR = 1.56 (95%CI 1.25-1.95). The relationship between maternal psychiatric conditions and ADHD in children yielded an aRR of 1.90 (95%CI 1.47-2.45). Three studies conducted sibling-matched analyses with aRR of 0.94 (95%CI 0.75-1.16). These data suggest that the observed association between prenatal use of antidepressants and risk of ADHD in offspring can be partially explained by confounding by indication because the results from sibling-matched analyses do not support an increased risk of ADHD in discordant exposed siblings.

Brand and generic use of inhalation medication and frequency of switching in children and adults: A population-based cohort study

BACKGROUND

The expiration of patents of brand inhalation medications and the ongoing pressure on healthcare budgets resulted in a growing market for generics.

AIM

To study the use of brand and generic inhalation medication and the frequency of switching between brand and generic and between devices. In addition, we investigated whether switching affected adherence.

METHODS

From dispensing data from the Dutch PHARMO Database Network a cohort aged ≥ 5 years, using ≥ 1 year of inhalation medication between 2003 and 2012 was selected. Switching was defined as changing from brand to generic or vice versa. In addition, we studied change in aerosol delivery device type (e.g., DPI, pMDI, and nebulizers). Adherence was calculated using the medication possession ratio (MPR).

RESULTS

The total cohort comprised 70,053 patients with 1,604,488 dispensations. Per calendar year, 5% switched between brand and generic inhalation medication and 5% switched between devices. Median MPRs over the first 12 months ranged between 33 and 55%. Median MPR over the total period was lower after switch from brand to generic and vice versa for formoterol (44.5 vs. 42.1 and 63.5 vs. 53.8) and beclomethasone (93.8 vs. 59.8 and 81.3 vs. 55.9).

CONCLUSION

Per year, switching between brand and generic inhalation medication was limited to 5% of the patients, switching between device types was observed in 5% as well. Adherence to both generic and brand inhalation medication was low. Effect of switching on adherence was contradictory; depending on time period, medication and type, and direction of switching. Further research on reasons for switching and potential impact on clinical outcomes is warranted.

Association of Risk of Suicide Attempts With Methylphenidate Treatment

IMPORTANCE

Patients with attention-deficit/hyperactivity disorder (ADHD) are at an increased risk of attempting suicide. Stimulants, such as methylphenidate hydrochloride, are the most common treatment for ADHD, but the association between their therapeutic use and suicide is unclear.

OBJECTIVE

To investigate the association between methylphenidate and the risk of suicide attempts.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, electronic medical records database from the Hong Kong Clinical Data Analysis & Reporting System was used to identify 25 629 individuals aged 6 to 25 years who were treated with methylphenidate between January 1, 2001, and December 31, 2015. Those who had attempted suicide were included in the analysis. A self-controlled case series design was used to control for time-invariant characteristics of the patients.

MAIN OUTCOMES AND MEASURES

Relative incidence of suicide attempt during periods when patients were exposed to methylphenidate compared with nonexposed periods.

RESULTS

Among 25 629 patients with methylphenidate prescriptions, 154 had their first recorded suicide attempt within the study period; of these individuals, 111 (72.1%) were male; mean (SD) age at baseline was 7.15 (2.19) years. The overall incidence of suicide attempts during methylphenidate treatment was 9.27 per 10 000 patient-years. An increased risk of suicide attempts was detected during the 90-day period before methylphenidate was initiated, with an incidence rate ratio (IRR) of 6.55 (95% CI, 3.37-12.72). The IRR remained elevated during the first 90 days of treatment (IRR, 3.91; 95% CI, 1.62-9.42) before returning to baseline levels during ongoing treatment (IRR, 1.35; 95% CI, 0.77-2.38). When the risk during the first 90 days of treatment was compared with the 90 days preceding first treatment, the incidence of suicide attempts was not elevated (IRR, 0.78; 95% CI, 0.26-2.35).

CONCLUSIONS AND RELEVANCE

The incidence of suicide attempts was higher in the period immediately before the start of methylphenidate treatment. The risk remained elevated immediately after the start of methylphenidate treatment and returned to baseline levels during continuation of methylphenidate treatment. The observed higher risk of suicide attempts before treatment may reflect emerging psychiatric symptoms that trigger medical consultations that result in a decision to begin ADHD treatment. Therefore, this study's results do not support a causal association between methylphenidate treatment and suicide attempts.

CodeMapper: semiautomatic coding of case definitions. A contribution from the ADVANCE project

BACKGROUND

Assessment of drug and vaccine effects by combining information from different healthcare databases in the European Union requires extensive efforts in the harmonization of codes as different vocabularies are being used across countries. In this paper, we present a web application called CodeMapper, which assists in the mapping of case definitions to codes from different vocabularies, while keeping a transparent record of the complete mapping process.

METHODS

CodeMapper builds upon coding vocabularies contained in the Metathesaurus of the Unified Medical Language System. The mapping approach consists of three phases. First, medical concepts are automatically identified in a free-text case definition. Second, the user revises the set of medical concepts by adding or removing concepts, or expanding them to related concepts that are more general or more specific. Finally, the selected concepts are projected to codes from the targeted coding vocabularies. We evaluated the application by comparing codes that were automatically generated from case definitions by applying CodeMapper's concept identification and successive concept expansion, with reference codes that were manually created in a previous epidemiological study.

RESULTS

Automated concept identification alone had a sensitivity of 0.246 and positive predictive value (PPV) of 0.420 for reproducing the reference codes. Three successive steps of concept expansion increased sensitivity to 0.953 and PPV to 0.616.

CONCLUSIONS

Automatic concept identification in the case definition alone was insufficient to reproduce the reference codes, but CodeMapper's operations for concept expansion provide an effective, efficient, and transparent way for reproducing the reference codes.

Prenatal antidepressant use and risk of attention-deficit/hyperactivity disorder in offspring: population based cohort study

Objective To assess the potential association between prenatal use of antidepressants and the risk of attention-deficit/hyperactivity disorder (ADHD) in offspring.Design Population based cohort study.Setting Data from the Hong Kong population based electronic medical records on the Clinical Data Analysis and Reporting System.Participants 190 618 children born in Hong Kong public hospitals between January 2001 and December 2009 and followed-up to December 2015.Main outcome measure Hazard ratio of maternal antidepressant use during pregnancy and ADHD in children aged 6 to 14 years, with an average follow-up time of 9.3 years (range 7.4-11.0 years).Results Among 190 618 children, 1252 had a mother who used prenatal antidepressants. 5659 children (3.0%) were given a diagnosis of ADHD or received treatment for ADHD. The crude hazard ratio of maternal antidepressant use during pregnancy was 2.26 (P<0.01) compared with non-use. After adjustment for potential confounding factors, including maternal psychiatric disorders and use of other psychiatric drugs, the adjusted hazard ratio was reduced to 1.39 (95% confidence interval 1.07 to 1.82, P=0.01). Likewise, similar results were observed when comparing children of mothers who had used antidepressants before pregnancy with those who were never users (1.76, 1.36 to 2.30, P<0.01). The risk of ADHD in the children of mothers with psychiatric disorders was higher compared with the children of mothers without psychiatric disorders even if the mothers had never used antidepressants (1.84, 1.54 to 2.18, P<0.01). All sensitivity analyses yielded similar results. Sibling matched analysis identified no significant difference in risk of ADHD in siblings exposed to antidepressants during gestation and those not exposed during gestation (0.54, 0.17 to 1.74, P=0.30).Conclusions The findings suggest that the association between prenatal use of antidepressants and risk of ADHD in offspring can be partially explained by confounding by indication of antidepressants. If there is a causal association, the size of the effect is probably smaller than that reported previously.

Use of azithromycin and risk of ventricular arrhythmia

BACKGROUND

There are conflicting findings from observational studies of the arrhythrogenic potential of azithromycin. Our aim was to quantify the association between azithromycin use and the risk of ventricular arrhythmia.

METHODS

We conducted a nested case-control study within a cohort of new antibiotic users identified from a network of 7 population-based health care databases in Denmark, Germany, Italy, the Netherlands and the United Kingdom for the period 1997-2010. Up to 100 controls per case were selected and matched by age, sex and database. Recency of antibiotic use and type of drug (azithromycin was the exposure of interest) at the index date (occurrence of ventricular arrhythmia) were identified. We estimated the odds of ventricular arrhythmia associated with current azithromycin use relative to current amoxicillin use or nonuse of antibiotics (≥ 365 d without antibiotic exposure) using conditional logistic regression, adjusting for confounders.

RESULTS

We identified 14 040 688 new antibiotic users who met the inclusion criteria. Ventricular arrhythmia developed in 12 874, of whom 30 were current azithromycin users. The mean age of the cases and controls was 63 years, and two-thirds were male. In the pooled data analyses across databases, azithromycin use was associated with an increased risk of ventricular arrhythmia relative to nonuse of antibiotics (adjusted odds ratio [OR] 1.97, 95% confidence interval [CI] 1.35-2.86). This increased risk disappeared when current amoxicillin use was the comparator (adjusted OR 0.90, 95% CI 0.48-1.71). Database-specific estimates and meta-analysis confirmed results from the pooled data analysis.

INTERPRETATION

Current azithromycin use was associated with an increased risk of ventricular arrhythmia when compared with nonuse of antibiotics, but not when compared with current amoxicillin use. The decreased risk with an active comparator suggests significant confounding by indication.

Are proton-pump inhibitors harmful for the semen quality of men in couples who are planning pregnancy?

OBJECTIVE

To determine associations between proton-pump inhibitor (PPI) use and semen parameters in young men of couples who are planning pregnancy.

DESIGN

Case-control study of a population-based registry.

SETTING

Not applicable.

PATIENT(S)

General practitioner patients comprising 2,473 men from couples planning pregnancy with a recorded semen analysis: 241 with a low total motile sperm count (TMSC ≤1) and 714 with TMSC >1 as matched controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Exposure to PPI; PPI dosage.

RESULT(S)

The study of data from between 1996 and 2013 from the Integrated Primary Care Information database in the Netherlands, which incorporates the medical records of 1.5 million patients from 720 general practitioners, found that the use of PPIs in the period between 12 and 6 months before semen analysis was associated with a threefold higher risk of low TMSC (odds ratio 2.96; 95% confidence interval 1.26-6.97) adjusted for age and other medication. Use of PPIs during the 6 months immediately before the semen analysis was not statistically significantly associated with low TMSC.

CONCLUSION(S)

The use of PPIs in the period 12 to 6 months preceding semen analysis is associated with a threefold higher risk of low TMSC, which suggests that a long-term increase in gastric pH results in a decline of sperm quality. This finding emphasizes the need for more preconceptional research and counseling on the potential effects of medication use on semen quality.

Patterns of spontaneous reports on narcolepsy following administration of pandemic influenza vaccine; a case series of individual case safety reports in Eudravigilance

OBJECTIVE

This study aims to describe the frequency and quality of spontaneous narcolepsy case reports following administration of pandemic influenza vaccine as captured in the Eudravigilance database.

METHODS

We conducted a retrospective descriptive study of spontaneous Individual Case Safety Reports (ICSRs), reporting narcolepsy following administration of pandemic influenza vaccine as received by Eudravigilance until July 2014. De-duplication was carried out by Eudravigilance. Frequency of reporting is described as number of ICSRs received per month over time. The quality of the ICSRs was evaluated by completeness of information and diagnostic certainty using the Automated Brighton Collaboration case definition tool (ABC-tool) for narcolepsy.

RESULTS

After de-duplication, a total of 1333 ICSRs of narcolepsy and/or cataplexy following pandemic influenza vaccine were identified, originating from 18 countries worldwide. Most of the ICSRs (61.9%) originated from the signaling countries, Sweden and Finland. Although de-duplication of case reports was carried out, it is suspected that many duplicates exist, in particular from Sweden. The majority of the ICSRs (95.3%), reported exposure to Pandemrix®. Only few reports were received for Arepanrix® (1.6%) or Focetria® (0.5%), and Celvapan® (0.1%). Of those ICSRs reporting age, 73.1% concerned persons below age of 20years. When using the ABC-tool, all ICSRs were classified as having insufficient information to meet the Brighton Collaboration case definition of narcolepsy.

CONCLUSION

An increase in reporting of narcolepsy appeared in Eudravigilance only after awareness was raised by the national authorities. Most narcolepsy reports were received from countries where the signal initially occurred, and were related to Pandemrix® in children/adolescents. Basic information about the patient and the exposure was present in most of the ICSRs. The ICSRs captured by Eudravigilance however, do not collect enough information to assess the diagnostic certainty according to the Brighton Collaboration case definition.

Real life data on incidence and risk factors of severe asthma exacerbations in children in primary care

Real-life data on the incidence rates (IR) and risk factors of severe asthma exacerbations in children are sparse. We aimed to assess IR and risk factors of severe asthma exacerbations in children in real life. We conducted a population-based cohort study using a Dutch GP database containing complete medical records of >1 million patients. All records of children with physician-diagnosed asthma aged 5-18 years between 2000 and 2012 were examined for exacerbations, defined as either hospitalization, emergency department visit or need of systemic steroids for asthma. IR was expressed as number of exacerbations per person year (PY). We identified 14,303 asthmatic children with 35,118 PY of follow-up and 732 exacerbations. The overall IR was 2.1/100PY (95% CI 1.9-2.2), 4.1/100PY (3.8-4.4) for children on asthma treatment. Re-exacerbation occurred in 2% (1.3-4.3) of patients within 1 month, in 25% (20.6-28.8) within 1 year. Predictors for (frequent) exacerbations were age, medication use and prior exacerbations (all p < 0.001). The overall IR of severe asthma exacerbations was 4/100PY in children on asthma treatment, highest in spring and fall. 25% of the patients with an exacerbation will experience a next exacerbation within 1 year. More severe asthma is a predictor of subsequent and future exacerbations.

Pharmacoepidemiological safety studies in children: a systematic review

Purpose

In order to identify challenges in pediatric pharmacoepidemiological safety studies, we assessed the characteristics of such (published) studies.

Methods

Relevant articles from inception to 2013 were retrieved from Embase and Medline. We sequentially screened titles, abstracts and full texts with independent validation. We systematically collected data regarding general information, study methods and results.

Results

Out of 4825 unique articles, 268 full texts (5.6%) were retained; 147 (54.9%) pertained to drugs rather than vaccines. Considering the 268 studies, 202 (75.4%) concerned children and adolescents (2 to 11 years) and 14 (5.3%) included preterm newborns. Most studies originated from North America (154 [57.5%]) or Europe (92 [34.3%]). Only 47 studies (17.5%) were privately funded. The majority (174 [64.9%]) were cohort studies. Out of 268 studies, 196 (73.1%) collected data retrospectively; paper medical charts were the most common data source for the exposures (85 [31.7%]) and outcomes (122 [45.5%]). Only 3 (2.0%) drug‐only studies investigated rarely used drugs. Considering all 268 studies, only 27 (10.1%) reported sample size or power calculation. Most (75 [51.0%]) drug‐only studies corrected confounding by multivariate modeling unlike stratification in 66 (55.9%) vaccine‐only studies. Considering 75 child‐only studies without any statistically significant result, 41 (54.7%) did not discuss lack of power.

Conclusions

Although the field of pediatric pharmacoepidemiology is steadily developing evaluation seldom includes neonates, is mainly focused on few drug classes and safety outcomes and concerns mainly drug use in developed countries. Small study size is a specific challenge in pediatrics. Reporting should be improved. © 2016 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.

Prescribing pattern of antipsychotic drugs during the years 1996-2010: a population-based database study in Europe with a focus on torsadogenic drugs

INTRODUCTION

Antipsychotic drugs (APDs) are used to treat several mental illnesses. Some APDs have long been known to be associated with QT prolongation, potentially leading to torsades de pointes (TdP) and sudden cardiac death (SCD). In 2005, thioridazine was withdrawn because of the risk of SCD, bringing further attention to the arrhythmogenic potential of APDs.

AIM

The aim of the current study was to evaluate the use of APDs in five European countries during the years 1996-2010.

METHODS

A cohort study was conducted using prescription/dispensing data from seven healthcare databases [the AARHUS University Hospital Database (Denmark), the German Pharmacoepidemiological Research Database (GePaRD) (Germany), Health Search Database/Thales (HSD) and Emilia Romagna Regional Database (ERD) (Italy), PHARMO Database Network and Integrated Primary Care Information (IPCI) (the Netherlands) and The Health Improvement Network (THIN) (the UK), covering a population of 27 million individuals. The annual prescription rate of APDs was measured overall and for individual medications. APDs were classified as torsadogenic according to the Arizona-CERT list. All analyses were stratified by age, gender and calendar year.

RESULTS

A total of 559 276 person-years (PYs) of exposure to APDs was captured. The crude annual prescription rate of APD use ranged from 3.0/1000 PYs in ERD to 7.7/1000 PYs in AARHUS. Among APDs with established torsadogenic potential, thioridazine was the most frequently used medication in the UK. Haloperidol was commonly prescribed in Italy and the Netherlands. The use of APDs with torsadogenic potential was much higher in elderly patients.

CONCLUSIONS

Substantial use of APDs with torsadogenic potential has been reported in Europe in recent years, in spite of increasing concerns about their arrhythmogenic potential. This use was even greater in elderly patients, who are at higher risk of SCD.

Prescription patterns, adherence and characteristics of non-adherence in children with asthma in primary care

Adherence to treatment remains important for successful asthma management. Knowledge about asthma medication use and adherence in real-life offers opportunities to improve asthma treatment in children.

OBJECTIVE

To describe prescription patterns, adherence and factors of adherence to drugs in children with asthma.

METHODS

Population-based cohort study in a Dutch primary care database (IPCI), containing medical records of 176,516 children, aged 5-18 years, between 2000 and 2012. From asthma medication prescriptions, age, gender, seasonal and calendar year rates were calculated. Adherence was calculated using medication possession ratio (MPR) and ratio of controller to total asthma drug (CTT). Characteristics of children with high-vs.-low adherence were compared.

RESULTS

The total asthma cohort (n = 14,303; 35,181 person-years (PY) of follow-up) was mainly treated with short-acting β2-agonists (SABA; 40 users/100 PY) and inhaled corticosteroids (ICS; 32/100 PY). Median MPR for ICS was 56%. Children with good adherence (Q4 = MPR > 87%) were younger at start of ICS, more often visited specialists and had more exacerbations during follow-up compared to children with low adherence (Q1 = MPR < 37%).

CONCLUSION

In Dutch primary care children with asthma were mainly prescribed SABA, and ICS. Adherence to ICS was relatively low. Characteristics of children with good adherence were compatible with more severe asthma, suggesting that adherence is driven by treatment need or intensity of medical follow-up.

Hospital Admissions, Transfers and Costs of Guillain-Barré Syndrome

Background

Guillain-Barré syndrome (GBS) has a highly variable clinical course, leading to frequent transfers within and between hospitals and high associated costs. We defined the current admissions, transfers and costs in relation to disease severity of GBS.

Methods

Dutch neurologists were requested to report patients diagnosed with GBS between November 2009 and November 2010. Information regarding clinical course and transfers was obtained via neurologists and general practitioners.

Results

87 GBS patients were included with maximal GBS disability score of 1 or 2 (28%), 3 or 4 (53%), 5 (18%) and 6 (1%). Four mildly affected GBS patients were not hospital admitted. Of the 83 hospitalized patients 68 (82%) were initially admitted at a neurology department, 4 (5%) at an ICU, 4 (5%) at pediatrics, 4 (5%) at pediatrics neurology and 3 (4%) at internal medicine. Median hospital stay was 17 days (IQR 11–26 days, absolute range 1–133 days). Transfers between departments or hospitals occurred in 33 (40%) patients and 25 (30%) were transferred 2 times or more. From a cost-effectiveness perspective 21 (25%) of the admissions was suboptimal. Median costs for hospital admission of GBS patients were 15,060 Euro (IQR 11,226–23,683). Maximal GBS disability score was significantly correlated with total length of stay, number of transfers, ICU admission and costs.

Conclusions

Hospital admissions for GBS patients are highly heterogeneous, with frequent transfers and higher costs for those with more severe disease. Future research should aim to develop prediction models to early identify the most cost-effective allocation in individual patients.