[ADHD medication to improve academic performance?] / Een pil voor een betere focus tijdens het studeren?

The Monitor Mental Health and Substance Use (2021) shows that almost one in twenty students has used ADHD medication for non-medical use at least once in the past year. Non-medical use is use without a doctor's prescription. In interviews, students mainly mention methylphenidate for this non-medical use. Students mention improved concentration for study activities as an important reason. Students often receive or buy the medication from friends or family who use the medicines on prescription. Some scientific studies show that ADHD medication in people without ADHD has a positive effect on cognitive performance, such as attention. However, the effects found are small and the research setting was not representative of daily practice. Also, the non-medical use does not seem to lead to better academic performance. In addition, little is known about safety. Therefore, non-medical use of ADHD-medication cannot be justified.

Infliximab use in the Netherlands: Uptake and characteristics of originator and biosimilars over time.

AIMS: The objective of this retrospective cohort study was to provide an overview of the utilization of originator and biosimilar infliximab in the Netherlands. METHODS: All infliximab dispensings were selected from the PHARMO In-patient Pharmacy Database from 2002-2018. Descriptive analyses were performed in order to characterise initiators and to describe switching patterns over time. RESULTS: Overall, 3840 patients with 61 274 infliximab dispensings were identified. 2496 patients initiated an originator infliximab and 777 patients initiated a biosimilar infliximab. Overall, 57% of the patients was female and mean age was 43.2 years. Both originators and biosimilars were mostly prescribed by gastroenterologists, followed by internists and rheumatologists. After market authorisation of the first biosimilar, the proportion of new patients initiating the biosimilar increased from 39% in 2015 to 91% in 2018. Out of 704 patients eligible for switching 34% switched. Among switchers, the proportion of females was 60% and mean age at index was 45.1 years. Among nonswitchers, 55% were female and mean age was 39.8 years. The median time to switch was 1.7 years and switchers were most frequently initiated on infliximab by a rheumatologist (42%), while nonswitchers were most frequently initiated by a gastroenterologist (42%). CONCLUSION: The results of this large population-based cohort show an increase in biosimilar initiation in daily clinical practice. The number of switchers remains relatively low as nonmedical switch is not encouraged in the Netherlands.

Existing Data Sources for Clinical Epidemiology: The PHARMO Database Network.

The PHARMO Database Network provides a unique opportunity to gain insight in the complete patient journey and healthcare in the Netherlands. The PHARMO Database Network is a population-based network of electronic healthcare databases and combines anonymous data from different primary and secondary healthcare settings in the Netherlands. Healthcare settings include general practitioners, out-patient and in-patient pharmacies, hospitals and clinical laboratories. Furthermore, databases are linked with external registries such as the Cancer Registry, Pathology Registry and Perinatal Registry. The different data sources are linked on a patient level through probabilistic linkage based on validated algorithms. The longitudinal and ongoing nature of the PHARMO Database Network system enables to follow up more than 10 million residents of the Netherlands for an average of 12 years. Data collection period, catchment area and overlap between data sources differ. Access to the PHARMO Database Network is, by governance regulations of the data collection, restricted to researchers of the PHARMO Institute and academic affiliates. Each data request is checked against privacy and company policies, and requires approval of the privacy and governance board. The terms and conditions and a data application form are available on the PHARMO website (www.pharmo.com).

Introducing new vaccines in low- and middle-income countries: challenges and approaches.

INTRODUCTION: The number of new vaccine introductions (NVIs) in low and middle-income countries (LMICs) has markedly increased since 2010, raising challenges to often overstretched and underfunded health care systems. AREAS COVERED: We present an overview of some of these challenges, focusing on programmatic decisions, delivery strategy, information and communication, pharmacovigilance and post-licensure evaluation. We also highlight field-based initiatives that may facilitate NVI. EXPERT COMMENTARY: Some new vaccines targeting populations other than infants require alternative delivery strategies. NVIs impact upon existing supply chain management, in particular vaccines with novel characteristics. A lack of understanding about immunization and misconceptions may be detrimental to NVI, as well as insufficient or poorly trained health care workforce. Many barriers exist to achieving good vaccination coverage. Real-world evaluation of vaccine safety, effectiveness and impact in LMICs may be limited by lack of robust demographic and disease epidemiology data, as well as limited health care and surveillance infrastructure. A thorough planning phase is crucial to define the most suitable delivery strategy based on the vaccine's and country's specificities. A communication plan and social mobilization are essential. Implementation research and innovative approaches applied to logistics, delivery, communication and program evaluation can facilitate NVI.

Risk of dipeptidyl peptidase-4 (DPP-4) inhibitors on site-specific cancer: A systematic review and meta-analysis.

The long-term impact of dipeptidyl peptidase-4 (DPP-4) inhibition is unknown, and there are concerns about the influence of DPP-4 inhibition on carcinogenesis of the pancreas and thyroid. As DPP-4 is a rather unselective enzyme present in many tissues, we focused on all specific cancer types. PubMed and EMBASE were searched between January 2005 and April 2017 to identify studies comparing DPP-4 inhibitors with either placebo or active drugs on cancer risk. Studies were included if they reported on at least one specific cancer outcome and had a follow-up of at least 1 year after start of drug use. Methodological quality of the studies was assessed by the Cochrane Collaboration's tool and the Newcastle-Ottawa Scale. Twenty-five studies met the inclusion criteria (12 randomized controlled trials and 13 observational studies). Sample sizes of the DPP-4 inhibitor groups ranged from 29 to 8212 patients for randomized controlled trials and from 2422 to 71 137 patients for observational studies. Mean age ranged from 51 to 76 years, and mean follow-up was 1.5 years. None of the pooled (sensitivity) analyses, except the observational studies studying breast cancer (hazard ratio [95% CI]: 0.76 [0.60-0.96]), showed evidence for an association between DPP-4 inhibitors and site-specific cancer. Also for pancreatic and thyroid cancer, no statistically significant risk was found. Based on the current literature, it is not possible to conclude whether DPP-4 inhibitors were associated with an increased risk of site-specific cancer. Future studies should address the methodological limitations and follow patients for a longer period to determine the long-term cancer risk of DPP-4 inhibitors.

The incidence, clearance and persistence of non-cervical human papillomavirus infections: a systematic review of the literature.

BACKGROUND: Human papillomavirus (HPV) vaccines were designed to prevent cervical cancer in women and their provision remains a major public health need. However, HPV is also a major cause of non-cervical anogenital and oropharyngeal cancers and the potential benefit of vaccination likely extends beyond cervical cancer. METHODS: A systematic literature search of PubMed (1995-2014) identified publications assessing the incidence, persistence, and clearance of non-cervical anogenital/oral HPV infections. Comparability with cervical HPV was assessed by identifying articles assessing the same or similar populations. RESULTS: Available data suggest high incidence rates of non-cervical HPV infection in men and women, with HPV-16 predominating in all sites. The incidence of high risk HPV per 100 person-years ranged from 11.4 to 72.9 for penile infections, 6.7-47.9 at other male genital sites, and 4.4-36.7 and 5.3-23.4 for anal infections in men and women, respectively. The incidence per 100 person-years of oral infection with any HPV type ranged from 5.7 to 6.7 in men and 6.8-39.6 in women. Within the limitations of the data, there was a general pattern of higher incidence and clearance of non-cervical genital HPV infections, compared to cervical infections. HIV status, circumcision, number of sex partners and partner HPV status significantly influenced high-risk HPV incidence/clearance at male anogenital sites. Few studies assessed risk factors for oral HPV. CONCLUSIONS: Parallels appear to exist between the epidemiology of cervical and non-cervical HPV infections in terms of incidence, HPV-type distribution, and risk factors for infection. Available data suggest that non-cervical genital HPV infections may occur more frequently, with higher clearance rates, than cervical infections. More extensive studies could provide useful information for estimating vaccine impact, the wider cost-benefit of HPV vaccination, and guiding vaccination policy. TRIAL REGISTRATION: Not applicable, as systematic review of the literature.

Immunogenicity, effectiveness and safety of combined hepatitis A and B vaccine: a systematic literature review.

BACKGROUND: Hepatitis A and B are two of the most common vaccine-preventable diseases and vaccination for Hepatitis A virus (HAV) and hepatitis B virus (HBV) is recommended for those at risk of contracting HAV and/or HBV through their occupation, travel or lifestyle. OBJECTIVE: To describe the vaccine efficacy, immunogenicity, effectiveness and safety of the combined vaccine against hepatitis A and hepatitis B. METHODS: A systematic review of the literature published between 1990 and 2015. RESULTS: Anti-HAV seropositivity rates ranged from 96.2% to 100% and anti-HBs seroprotection rates from 82% to 100%. Antibodies persisted up to 15 years and geometric mean concentration (GMC) remained above the seropositivity cut-off value for both. Anti-HAV and anti-HBs immune responses were lower in less immunocompetent individuals one month after completion of the immunization schedule. The safety profiles of Twinrix(TM) and monovalent hepatitis A and B vaccines were similar. CONCLUSION: The vaccine offers satisfactory long-term immunogenicity rates, expected duration of protection and safety profile similar to the monovalent hepatitis A or B vaccines.

Selective decontamination of the digestive tract and selective oropharyngeal decontamination in intensive care unit patients: a cost-effectiveness analysis.

OBJECTIVE: To determine costs and effects of selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) as compared with standard care (ie, no SDD/SOD (SC)) from a healthcare perspective in Dutch Intensive Care Units (ICUs). DESIGN: A post hoc analysis of a previously performed cluster-randomised trial (NEJM 2009;360:20). SETTING: 13 Dutch ICUs. PARTICIPANTS: Patients with ICU-stay of >48 h that received SDD (n=2045), SOD (n=1904) or SC (n=1990). INTERVENTIONS: SDD or SOD. PRIMARY AND SECONDARY OUTCOME MEASURES: Effects were based on hospital survival, expressed as crude Life Years Gained (cLYG). The incremental cost-effectiveness ratio (ICER) was calculated, with corresponding cost acceptability curves. Sensitivity analyses were performed for discount rates, costs of SDD, SOD and mechanical ventilation. RESULTS: Total costs per patient were €41 941 for SC (95% CI €40 184 to €43 698), €40 433 for SOD (95% CI €38 838 to €42 029) and €41 183 for SOD (95% CI €39 408 to €42 958). SOD and SDD resulted in crude LYG of +0.04 and +0.25, respectively, as compared with SC, implying that both SDD and SOD are dominant (ie, cheaper and more beneficial) over SC. In cost-effectiveness acceptability curves probabilities for cost-effectiveness, compared with standard care, ranged from 89% to 93% for SOD and from 63% to 72% for SDD, for acceptable costs for 1 LYG ranging from €0 to €20 000. Sensitivity analysis for mechanical ventilation and discount rates did not change interpretation. Yet, if costs of the topical component of SDD and SOD would increase 40-fold to €400/day and €40/day (maximum values based on free market prices in 2012), the estimated ICER as compared with SC for SDD would be €21 590 per LYG. SOD would remain cost-saving. CONCLUSIONS: SDD and SOD were both effective and cost-saving in Dutch ICUs.

Added value of CAC in risk stratification for cardiovascular events: a systematic review.

BACKGROUND: Identification of individuals at high risk for cardiovascular disease (CVD) is important to initiate adequate treatment and to prevent future events. Moreover, identification of low-risk individuals is important to refrain from unneeded therapy. Current risk prediction models do not accurately predict the risk of CVD in individuals, and new markers have been sought to improve the risk assessment in individuals. Coronary artery calcification (CAC) is a marker of atherosclerosis that might improve current risk assessment when added to traditional risk factors. MATERIALS AND METHODS: We performed a systematic review on PubMed search (1 February 2011) on studies reporting on the added value of CAC in risk prediction in asymptomatic individuals. RESULTS: Of 39 publications on CAC and CVD, nine studies were carried out in asymptomatic individuals. All studies showed an increase in area under the curve ranging from 0.05 to 0.20 when CAC was added to the risk model. Four studies reported on improvements of individuals in low-, intermediate-, and high-risk categories. Addition of CAC to the risk model resulted in a net reclassification improvement ranging from 14% to 30%, meaning that CAC measurement reclassified a substantial proportion of individuals into correct risk categories. This improvement was most pronounced in those at intermediate Framingham risk. CONCLUSIONS: The available studies consistently showed that CAC scoring improves risk stratification in CVD risk categories when added to traditional risk factors only, especially among individuals at intermediate risk for CVD. Cost-effectiveness analyses together with a randomized controlled trial are needed before widespread introduction of CAC in clinical care.