Koen B. Pouwels

Primary prevention of major cardiovascular and cerebrovascular events with statins in diabetic patients : a meta-analysis

BackgroundPatients with diabetes mellitus are at increased risk of developing cardiovascular disease. Controlling lipid levels has a preventive effect on the occurrence of major cardiovascular and cerebrovascular events. Individual trials have shown varying data on the efficacy of treatment with lipid-lowering statin therapy in the primary prevention of such events in diabetes.ObjectiveThe objective of this study was to assess the efficacy of statins in the primary prevention of the first-time occurrence of a major cardiovascular or cerebrovascular event in diabetic patients. Secondary endpoints were fatal/non-fatal stroke, fatal/non-fatal myocardial infarction and all-cause mortality.MethodsA systematic search for trial reports was conducted in PubMed, EMBASE, The Cochrane library and clinicaltrials.gov for the years 1966–2011. Reference lists of reviews and meta-analyses of related subjects were searched. High-quality, randomized, double-blinded clinical trials comparing a statin with placebo for the primary prevention of major cardiovascular and cerebrovascular events in diabetic patients were selected. Only large studies with a minimum of 500 diabetic participants followed-up for at least 2 years were included. Endpoints were major cardiovascular and cerebrovascular events.Trial and patient characteristics were extracted by three researchers. The quality of the included studies was tested with the Jadad score. The combined effect on primary as well as secondary endpoints was measured with a fixed-effect model. Publication bias was examined with a funnel plot.ResultsFour trials were included, for a total of 10 187 participants. Treatment with statins in the primary prevention of major cardiovascular and cerebrovascular events in diabetic patients resulted in a significant relative risk (RR) reduction in the first-time occurrence of major cardiovascular or cerebrovascular events (RR 0.75, 95% CI 0.67–0.85), fatal/non-fatal stroke (RR 0.69, 95% CI 0.51–0.92) and fatal/non-fatal myocardial infarction (RR 0.70, 95% CI 0.54–0.90) and a non-significant RR reduction in all-cause mortality (RR 0.84, 95% CI 0.65–1.09). Among the studies there was non-significant heterogeneity in the individual effect estimates and no publication bias.LimitationsExclusion criteria and endpoints varied slightly between studies. The type and dosing of statin therapy differed between studies. Non-compliance in the statin treatment group and the use of statin treatment in the placebo group could have led to lower risk reductions.ConclusionTreatment with statins in primary prevention among diabetic patients has a significant beneficial effect on event rates of the first-time occurrence of a major cardiovascular or cerebrovascular event, fatal/non-fatal stroke and fatal/non-fatal myocardial infarction. There was a non-significant RR reduction in all-cause mortality.

Cost-effectiveness of vaccination against meningococcal B among Dutch infants: Crucial impact of changes in incidence.

Objective: Recently, a vaccine with the capacity to protect against serogroup B meningococcal (MenB) disease received a positive opinion of the European Medicines Agency. Previously, such a vaccine was estimated to be cost-effective. However, since then, the MenB disease incidence has declined drastically in the Netherlands. Therefore, we re-assessed the potential incremental cost-effectiveness ratio (ICER) of vaccinating infants in the Netherlands with a MenB vaccine. Methods: A cohort of 185,000 Dutch newborns was followed in a Markov model to compare routine vaccination against MenB disease with no vaccination. The ICER was estimated for different disease incidences. The study was performed from a societal perspective. Results: Routine infant vaccination (2, 3, 4+11 mo) could prevent 39 cases of MenB disease in a single birth cohort, corresponding to a total gain of 133 quality-adjusted life years (QALYs). However, this strategy is unlikely to be cost-effective if the vaccine costs €40 per dose (€243,778 per QALY). At a disease incidence of 5.7 per 100,000 person-years or a vaccine price of €10 per dose including administration costs, the ICER becomes more acceptable and remains below a threshold of €50,000 per QALY. Conclusions: At the current low level of disease incidence, introduction of routine infant vaccination, following a 2, 3, 4+11 mo schedule, against MenB disease is unlikely cost-effective in the Netherlands. If the MenB disease incidence increases or the vaccine price is substantially lower than €40, routine infant vaccination has the potential to be cost-effective.

Cost-effectiveness of vaccination of the elderly against herpes zoster in The Netherlands

BACKGROUND Each year a substantial number of Dutch elderly suffers from herpes zoster (HZ), caused by the reactivation of the varicella zoster virus (VZV). A potential complication of HZ is postherpetic neuralgia (PHN) which results in a prolonged loss of quality of life. A large randomized clinical trial, labelled the Shingles Prevention study (SPS), demonstrated that a live attenuated VZV vaccine can reduce the incidence of HZ and PHN. OBJECTIVE We aimed to estimate the incremental cost-effectiveness ratio (ICER) of vaccination of the elderly against HZ versus no such vaccination in The Netherlands. METHODS A cohort model was developed to compare the costs and effects in a vaccinated and a non-vaccinated age- and gender-stratified cohort of immune-competent elderly. Vaccination age was varied from 60 to 75 years. Data from published literature such as the SPS were used for transition probabilities. The study was performed from the societal as well as the health care payers perspective and results were expressed in euros per quality-adjusted life year (QALY) gained. RESULTS In the base case, we estimated that vaccination of a cohort of 100,000 60-year-olds would prevent 4136 cases of HZ, 305 cases of PHN resulting in a QALY-gain of 209. From the societal perspective, a total of €1.9 million was saved and the ICER was €35,555 per QALY gained when a vaccine price of €87 was used. Vaccination of women resulted in a lower ICER than vaccination of men (€33,258 vs. €40,984 per QALY gained). The vaccination age with the most favourable ICER was 70 years (€29,664 per QALY gained). Parameters with a major impact on the ICER were the vaccine price and HZ incidence rates. In addition, the model was sensitive to utility of mild pain, vaccine efficacy at the moment of uptake and the duration of protection induced by the vaccine. CONCLUSION Vaccination against HZ might be cost-effective for ages ranging from 60 to 75 when a threshold of €50,000 per QALY gained would be used, at €20,000 per QALY this might not be the case. Additional information on the duration of vaccine-protection is needed to further optimize cost-effectiveness estimations.

The rosiglitazone decision process at FDA and EMA. What should we learn

In September 2010 the EMA decided to suspend the market authorisation of rosiglitazone, while the FDA decided to restrict the use of rosiglitazone. These actions were taken approximately 10 years after the introduction of rosiglitazone, because rosiglitazone might be associated with an increased risk of ischemic heart disease. It is often stated that the first signs of an increased risk of ischemic heart disease were noticed in 2004, however already in 2001 the FDA concluded, based on data available to the EMA at the time of initial approval, that rosiglitazone should not be used in combination with insulin, because this combination therapy was associated with an increased risk of cardiac failure and ischemic heart disease. Remarkably, in 2007, when the evidence against this combination therapy had increased, the EMA made a decision that encouraged the use of insulin in combination with rosiglitazone, while the FDA tried to restrict this combination therapy. Despite the publication of several studies, including a large randomized controlled study, the cardiovascular risk of rosiglitazone still has not been definitively established. The weight given to the benefits and the risks seems mainly a subjective decision. To prevent new cases like rosiglitazone, more attention should be given to evaluation of study protocols of safety trials prior to their starts. This paper gives a critical overview of the decision making process at the FDA and the EMA on the basis of public available information.

Meningococcal Serogroup A, C, W135 and Y Conjugated Vaccine: A Cost-Effectiveness Analysis in the Netherlands

Background In 2002, vaccination with a serogroup C meningococcal conjugate vaccine (MenC) was introduced in the Netherlands for all children aged 14 months. Despite its success, herd immunity may wane over time. Recently, a serogroup A,C,W135,Y meningococcal conjugate vaccine (MenACWY) was licensed for use in subjects of 12 months of age and above. Objectives To evaluate the cost-effectiveness of meningococcal vaccination at 14 months and an additional vaccination at the age of 12 years, both with the MenACWY vaccine. Methods A decision analysis cohort model, with 185,000 Dutch newborns, was used to evaluate the cost-effectiveness of different immunization strategies. For strategies including a vaccination at 12 years of age, an additional cohort with adolescents aged 12 years was followed. The incremental cost-effectiveness ratio (ICER) was estimated for the current disease incidence and for a scenario when herd immunity is lost. Results Vaccination with MenACWY at 14 months is cost-saving. Vaccinating with MenACWY at 14 months and at 12 years would prevent 7 additional cases of meningococcal serogroup A,C,W135,Y disease in the birth cohort and adolescent cohort followed for 99 years compared to the current vaccine schedule of a single vaccination with MenC at 14 months. With the current incidence, this strategy resulted in an ICER of €635,334 per quality adjusted life year. When serogroup C disease incidence returns to pre-vaccination levels due to a loss of vaccine-induced herd-immunity, vaccination with MenACWY at 14 months and at 12 years would be cost-saving. Conclusions Routine vaccination with MenACWY is cost-saving. With the current epidemiology, a booster-dose with MenACWY is not likely cost-effective. When herd immunity is lost, a booster-dose has the potential of being cost-effective. A dynamic model should be developed for more precise estimation of the cost-effectiveness of the prevention of disappearance of herd immunity.

Effect of pravastatin and fosinopril on recurrent urinary tract infections

OBJECTIVES Recurrent urinary tract infections (UTIs) are a problem affecting both women and men. Animal experiments and in vitro studies indicate that statins might prevent recurrent UTIs. We assessed the effects of pravastatin on UTI antibiotic prescribing among adults. METHODS A post hoc analysis was conducted with data from PREVEND IT, a trial among participants randomized to receive pravastatin, fosinopril or placebo in a 2 × 2 factorial design over 4 years. Trial data were linked to the pharmacy prescription database IADB.nl. The primary outcome was the number of prescriptions with a nitrofuran derivate, a sulphonamide or trimethoprim as a proxy for UTI antibiotic prescribing. Generalized estimating equations were used to estimate the effect on the number of UTI antibiotic prescriptions. Cox regression was used to determine the effect on first and second (recurrent) UTI antibiotic prescriptions. RESULTS Of the 864 trial participants, 655 were eligible for analysis. During an average follow-up of 3.8 years, 112 (17%) participants received at least one UTI antibiotic prescription. Intention-to-treat analyses showed that pravastatin was associated with a reduced total number of UTI antibiotic prescriptions (relative risk, 0.43; 95% CI, 0.21-0.88) and occurrence of second UTI antibiotic prescriptions [hazard ratio (HR), 0.25; 95% CI, 0.08-0.77]. No significant effect on occurrence of first UTI antibiotic prescriptions was found (HR, 0.83; 95% CI, 0.57-1.20). Fosinopril was associated with an increased occurrence of first UTI antibiotic prescriptions (HR, 1.82; 95% CI, 1.16-2.88). Combination therapy with fosinopril and pravastatin did not significantly influence the number of UTI antibiotic prescriptions. CONCLUSIONS This study suggests that pravastatin can reduce the occurrence of recurrent UTIs. Larger studies among patients with recurrent UTIs are warranted.

Quality of reporting of confounding remained suboptimal after the STROBE guideline.

OBJECTIVES Poor quality of reporting of confounding has been observed in observational studies prior the STrenghtening the Reporting of Observational studies in Epidemiology (STROBE) statement, a reporting guideline for observational studies. We assessed whether the reporting of confounding improved after the STROBE statement. STUDY DESIGN AND SETTING We searched MEDLINE for all articles about observational cohort and case-control studies on interventions with a hypothesized beneficial effect in five general medical and five epidemiologic journals published between January 2010 and December 2012. We abstracted data for the baseline period before the publication of the STROBE statement (January 2004-April 2007) from a prior study. Six relevant items related to confounding were scored for each article. A comparison of the median number of items reported in both periods was made. RESULTS In total, 174 articles published before and 220 articles published after the STROBE statement were included. The median number reported items was similar before and after the publication of the STROBE statement [median, 4; interquartile range [IQR], 3-5 vs. median, 4; IQR, 3.75-5]. However, the distribution of the number of reported items shifted somewhat to the right (P = 0.01). CONCLUSION Although the quality of reporting of confounding improved in certain aspects, the overall quality remains suboptimal.

Antibiotic use during pregnancy and asthma in preschool children: the influence of confounding.

A recent study suggested that early‐life intestinal microbiota may play an important role in the development of childhood asthma, indicating that antibiotics taken during early life or in late pregnancy may be associated with childhood asthma.

Antibiotics in primary care in England: which antibiotics are prescribed and for which conditions?

Objectives To analyse antibiotic prescribing behaviour in English primary care with particular regard to which antibiotics are prescribed and for which conditions. Methods Primary care data from 2013-15 recorded in The Health Improvement Network (THIN) database were analysed. Records with a prescription for systemic antibiotics were extracted and linked to co-occurring diagnostic codes, which were used to attribute prescriptions to clinical conditions. We further assessed which antibiotic classes were prescribed and which conditions resulted in the greatest share of prescribing. Results The prescribing rate varied considerably among participating practices, with a median of 626 prescriptions/1000 patients (IQR 543-699). In total, 69% of antibiotic prescriptions (n = 3 156 507) could be linked to a body system and/or clinical condition. Of these prescriptions, 46% were linked to conditions of the respiratory tract, including ear, nose and throat (RT/ENT); leading conditions within this group were cough symptoms (22.7%), lower respiratory tract infection (RTI) (17.9%), sore throat (16.7%) and upper RTI (14.5%). After RT/ENT infections, infections of the urogenital tract (22.7% of prescriptions linked to a condition) and skin/wounds (16.4%) accounted for the greatest share of prescribing. Penicillins accounted for 50% of all prescriptions, followed by macrolides (13%), tetracyclines (12%) and trimethoprim (11%). Conclusions The majority of antibiotic prescriptions in English primary care were for infections of the respiratory and urinary tracts. However, in almost one-third of all prescriptions no clinical justification was documented. Antibiotic prescribing rates varied substantially between practices, suggesting that there is potential to reduce prescribing in at least some practices.

Potential for reducing inappropriate antibiotic prescribing in English primary care

Objectives To identify and quantify inappropriate systemic antibiotic prescribing in primary care in England, and ultimately to determine the potential for reduction in prescribing of antibiotics. Methods Primary care data from 2013-15 recorded in The Health Improvement Network (THIN) database were used. Potentially inappropriate prescribing events in the database were identified by: (i) comparing prescribing events against treatment guidelines; (ii) comparing actual proportions of consultations resulting in prescription for a set of conditions with the ideal proportions derived from expert opinion; and (iii) identifying high prescribers and their number of prescriptions above an age- and body-system-specific benchmark. Results Applying the most conservative assumptions, 8.8% of all systemic antibiotic prescriptions in English primary care were identified as inappropriate, and in the least conservative scenario 23.1% of prescriptions were inappropriate. All practices had non-zero reduction potentials, ranging from 6.4% to 43.5% in the middle scenario. The four conditions that contributed most to inappropriate prescribing were sore throat (23.0% of identified inappropriate prescriptions), cough (22.2%), sinusitis (7.6%) and acute otitis media (5.7%). One-third of all antibiotic prescriptions lacked an informative diagnostic code. Conclusions This work demonstrates (i) the existence of substantial inappropriate antibiotic prescribing and (ii) poor diagnostic coding in English primary care. All practices (not just the high prescribers) should engage in efforts to improve antimicrobial stewardship. Better diagnostic coding, more precise prescribing guidelines and a deeper understanding of appropriate long-term uses of antibiotics would allow identification of further potential for reductions.