Incidence and serotype distribution of invasive group B streptococcal disease in young infants: a multi-country observational study.

BACKGROUND: Group B Streptococcus (GBS) is a leading cause of serious infection in very young infants. Robust incidence data from many geographic regions, including Latin America and Asia, are however lacking. METHODS: A multicenter, hospital-based observational study was performed in Panama, Dominican Republic, Hong Kong and Bangladesh. All represented urban, tertiary referral hospitals, except Bangladesh. GBS cases (microbiological isolation from normally sterile sites in infants aged 0-89 days) were collected over 12 months. RESULTS: At 2.35 (95% CI: 1.74-3.18) cases per 1000 live births, the incidence of early onset GBS disease (EOD) was highest in the Dominican Republic, compared with 0.76 (95% CI: 0.41-1.39) in Hong Kong and 0.77 (95% CI: 0.44-1.35) in Panama, while no cases were identified in Bangladesh. Over 90% of EOD cases occurred on the first day of life, with case fatality ratios ranging from 6.7% to 40%, varying by center, age of onset and clinical presentation. Overall, 90% of GBS (EOD and late onset disease) was due to serotypes Ia, Ib and III. CONCLUSIONS: The incidence rate of early onset GBS infection reported in Dominican Republic was not dissimilar from that described in the United States prior to screening and intrapartum antibiotic prophylaxis, while the incidence in Hong Kong was higher than previously reported in the Asian region. The failure to identify GBS cases in Bangladesh highlights a need to better understand the contribution of population, healthcare and surveillance practice to variation in reported incidence. Overall, the identified disease burden and serotype distribution support the need for effective prevention methods in these populations, and the need for community based surveillance studies in rural areas where access to healthcare may be challenging.

Variation in reported neonatal group B streptococcal disease incidence in developing countries.

Group B Streptococcus (GBS) is a leading cause of neonatal sepsis in developed countries. Its burden in the developing world is less clear. Studies reporting neonatal GBS disease incidence from developing countries were identified from 5 literature databases. Studies were assessed with respect to case finding and culture methods. Only 20 studies were identified. The GBS incidence ranged 0-3.06 per 1000 live births with variation within and between geographic regions. All but 1 study identified GBS cases within a hospital setting, despite the potential for births in the community. Possible case under-ascertainment was only discussed in 2 studies. A higher GBS incidence was reported when using automated culture methods. Prospective, population-based surveillance is urgently needed in developing countries to provide an accurate assessment of the neonatal GBS disease burden. This will be crucial for the design of interventions, including novel vaccines, and the understanding of their potential to impact mortality from neonatal sepsis.

Integration of Real-World Data and Genetics to Support Target Identification and Validation.

Even modest improvements in the probability of success of selecting drug targets which are ultimately approved can substantially reduce the costs of research and development. Drug targets with human genetic evidence of disease association are twice as likely to lead to approved drugs. A key enabler of identifying and validating these genetically validated targets is access to association results from genome-wide genotyping, whole-exome sequencing, and whole-genome sequencing studies with observable traits (often diseases) across large numbers of individuals. Today, linkage between genotype and real-world data (RWD) provides significant opportunities to not only increase the statistical power of genome-wide association studies by ascertaining additional cases for diseases of interest, but also to improve diversity and coverage of association studies across the disease phenome. As RWD-genetics linked resources continue to grow in diversity of participants, breadth of data captured, length of observation, and number of participants, there is a greater need to leverage the experience of RWD experts, clinicians, and highly experienced geneticists together to understand which lessons and frameworks from general research using RWD sources are relevant to improve genetics-driven drug discovery and development. This paper describes new challenges and opportunities for phenotypes enabled by diverse RWD sources, considerations in the use of RWD phenotypes for disease gene identification across the disease phenome, and challenges and opportunities in leveraging RWD phenotypes in target validation. The paper concludes with views on the future directions for phenotype development using RWD, and key questions requiring further research and development to advance this nascent field.

Risk factors for antiepileptic drug regimen change in patients with newly diagnosed epilepsy.

This study aimed to investigate the evolution of treatment within patients with newly diagnosed epilepsy identified from a large US commercial health care database. Postdiagnosis, patient follow-up was divided into observation units defined by consecutive antiepileptic drug (AED) prescriptions. Consecutive prescriptions were compared to assess whether a change in AED regimen had occurred. Factors associated with a regimen change were explored using a logistic regression model with subject random effects. Among 5930 patients with newly diagnosed epilepsy, there was a median of one regimen change in the first year. However, patients prescribed polytherapy regimens early in the course of disease were at a substantially greater risk of a regimen change (polytherapy vs monotherapy odds ratio=10.2, 95% confidence interval=9.2-11.3). Although a seizure during the preceding 90 days significantly increased the risk of a regimen change, it was beyond the scope of the study to determine the proportion of changes directly attributable to uncontrolled seizures.

Impact of nonadherence to antiepileptic drugs on health care utilization and costs: findings from the RANSOM study.

PURPOSE: To study the impact of nonadherence to antiepileptic drugs (AEDs) on health care utilization and direct medical costs in a Medicaid population. METHODS: A retrospective cohort design was employed using state Medicaid claims data from Florida, Iowa, and New Jersey during the period from January 1997 to June 2006. Patients aged >or=18 years with one or more neurologist visit with an epilepsy diagnosis and two or more pharmacy claims for AEDs were included. Medication possession ratio (MPR) was used to evaluate AED adherence with MPR >or= 0.80 considered adherent and <0.80 considered nonadherent. The association of nonadherence with utilization outcomes [hospitalizations, inpatient days, emergency department (ED), and outpatient visits] was assessed with univariate and multivariate Poisson regressions. Quarterly per-patient inpatient, outpatient, ED, and pharmacy costs were calculated across nonadherent and adherent quarters for the younger than 65 population (under-65) and cost differences were computed. Adjusted incremental costs of nonadherence were estimated with multivariate Tobit regression models. RESULTS: A total of 33,658 patients were included (28,470 under-65), together contributing 388,564 treated quarters (26% nonadherent). In multivariate analyses, AED nonadherence was associated with significantly higher incidence of hospitalizations [incident rate ratio (IRR) = 1.39, 95% confidence interval (CI) = 1.37-1.41], inpatient days (IRR = 1.76, 95% CI = 1.75-1.78), and ED visits (IRR = 1.19, 95% CI = 1.18-1.21). Nonadherence was associated with cost increases related to serious outcomes, including inpatient ($4,320 additional cost per quarter, 95% CI = $4,077-$4,564) and ED services ($303 additional cost per quarter, 95% CI = $273-$334), but lower costs for outpatient and pharmacy services, likely because of nonadherent behavior. DISCUSSION: Nonadherence to AEDs appears to be associated with serious outcomes, as evidenced by increased utilization and costs of inpatient and ED services.

Data resources for investigating drug exposure during pregnancy and associated outcomes: the General Practice Research Database (GPRD) as an alternative to pregnancy registries.

Pregnancy registries are the most commonly used data resource for the post-marketing surveillance of drug teratogenicity. However, the limited sample size and potential selection bias in these registries has led us to investigate the potential of the UK General Practice Research Database (GPRD) as an alternative data source for monitoring drug safety during pregnancy. In addition, a literature review identified further observational data sources that monitor pregnancy outcomes for future evaluation. Initial feasibility studies focused on the ability of the GPRD to capture pregnancy outcomes for a range of drug class exposures, all of which are currently under investigation in pregnancy registries, during pregnancy. The comparator pregnancy registries were identified via a MEDLINE search, whilst eligible pregnancies, in which women received one or more prescriptions for the drug of interest during pregnancy, were identified in the GPRD using the mother-baby link. The number of pregnancy outcomes following exposure to medication for a range of conditions with varying prevalence, including depression, migraine, epilepsy, herpes simplex and HIV, captured by the two data sources were compared. For depression, a relatively prevalent condition, the GPRD recorded the same number of mean annual intrauterine exposures to fluoxetine as the pregnancy registry (118 exposures/year). Ascertainment of intrauterine exposure to drug treatments for less prevalent conditions was found to be higher for the pregnancy registries than the GPRD; for the older antiepileptic drugs (valproate and carbamazepine), the pregnancy registry recorded between four and five times as many mean annual exposures as the GPRD. Virtually no antiretroviral exposures (three) were identified during the time period of interest on the GPRD, compared with 3946 in the Antiretroviral Pregnancy Registry. Data from the GPRD meet established criteria for evaluating outcomes of pregnancy. For prevalent conditions, it has the potential to replace or work alongside standard pregnancy registries and the alternative data sources identified. Further studies are now needed to assess its ability to replicate known teratogenic associations.

Prevalence of maternal colonisation with group B streptococcus: a systematic review and meta-analysis.

BACKGROUND: The most important risk factor for early-onset (babies younger than 7 days) invasive group B streptococcal disease is rectovaginal colonisation of the mother at delivery. We aimed to assess whether differences in colonisation drive regional differences in the incidence of early-onset invasive disease. METHODS: We did a systematic review of maternal group B streptococcus colonisation studies by searching MEDLINE, Embase, Pascal Biomed, WHOLIS, and African Index Medicus databases for studies published between January, 1997, and March 31, 2015, that reported the prevalence of group B streptococcus colonisation in pregnant women. We also reviewed reference lists of selected studies and contacted experts to identify additional studies. Prospective studies in which swabs were collected from pregnant women according to US Centers for Disease Control and Prevention guidelines that used selective culture methods were included in the analyses. We calculated mean prevalence estimates (with 95% CIs) of maternal colonisation across studies, by WHO region. We assessed heterogeneity using the I(2) statistic and the Cochran Q test. FINDINGS: 221 full-text articles were assessed, of which 78 studies that included 73 791 pregnant women across 37 countries met prespecified inclusion criteria. The estimated mean prevalence of rectovaginal group B streptococcus colonisation was 17·9% (95% CI 16·2-19·7) overall and was highest in Africa (22·4, 18·1-26·7) followed by the Americas (19·7, 16·7-22·7) and Europe (19·0, 16·1-22·0). Studies from southeast Asia had the lowest estimated mean prevalence (11·1%, 95% CI 6·8-15·3). Significant heterogeneity was noted across and within regions (all p≤0·005). Differences in the timing of specimen collection in pregnancy, selective culture methods, and study sample size did not explain the heterogeneity. INTERPRETATION: The country and regional heterogeneity in maternal group B streptococcus colonisation is unlikely to completely explain geographical variation in early-onset invasive disease incidence. The contribution of sociodemographic, clinical risk factor, and population differences in natural immunity need further investigation to understand these regional differences in group B streptococcus maternal colonisation and early-onset disease. FUNDING: None.

Comparing the General Practice Research Database and the UK Epilepsy and Pregnancy Register as tools for postmarketing teratogen surveillance: anticonvulsants and the risk of major congenital malformations.

BACKGROUND: Use of pregnancy registries is a common method of postmarketing surveillance of pregnancy outcomes to identify potential teratogens. However, with the increase in electronic capture of healthcare data for administrative, audit and research purposes, data generated during routine clinical practice might be used to address questions similar to those explored using pregnancy registries. OBJECTIVES: To establish how data from the UK General Practice Research Database (GPRD) compares with data from the UK Epilepsy and Pregnancy Register and to assess how it can contribute to postmarketing surveillance of pregnancy outcomes. METHODS: Pregnancy outcomes were identified from the GPRD for women aged 14-49 years with a diagnosis of epilepsy and supporting evidence. Outcomes with a major congenital malformation (MCM) were identified and the relative risks (RRs) of an MCM following a range of first-trimester antiepileptic drug (AED) exposures were calculated and compared with those reported by the UK Epilepsy and Pregnancy Register. In addition, we also evaluated whether the known association between valproate and spina bifida could be identified using data from the GPRD. The study period ran from 1 January 1990 until 31 December 2006. RESULTS: A total of 1766 live mother-baby pairs were identified, as well as 551 pregnancy terminations, 13 stillbirths and 1 neonatal death. Including those that resulted in a termination, there were 62 unique pregnancy outcomes with an MCM. An increased risk of spina bifida was identified using the GPRD following first-trimester monotherapy exposure to valproate when compared with those with no AED exposure (RR 8.02; 95% CI 1.5, 43.5). More generally, comparing the GPRD with the UK register, the GPRD ascertained a lower number of first-trimester AED exposures: monotherapy 711 versus 2468; polytherapy 156 versus 718. We reproduced the UK register results of an increased MCM risk following first-trimester polytherapy AED exposure compared with no AED exposure (RR 2.89; 95% CI 1.43, 5.84). Using the GPRD, we identified similar point estimates to the UK register following monotherapy and polytherapy exposures (4.1% vs 3.7% and 7.1% vs 6.0%, respectively) but we were unable to reproduce the level of statistical significance. For individual AEDs, the MCM rate following valproate exposure was 4.9% (11/225) in the GPRD compared with 6.2% (44/715) in the UK register. CONCLUSIONS: The GPRD has potential for the identification of malformations and of a teratogenic association. For epilepsy, the GPRD does, however, identify fewer exposed pregnancies than a pregnancy registry. Therefore, in many circumstances pregnancy registries are likely to remain preferable as a method of surveillance. The GPRD may be better suited to monitoring medicines used in the treatment of more prevalent conditions, such as depression, or for monitoring medicines that have been on the market for a long time and for which no registry has been set up.

Identifying major congenital malformations in the UK General Practice Research Database (GPRD): a study reporting on the sensitivity and added value of photocopied medical records and free text in the GPRD.

BACKGROUND: Postmarketing teratogen surveillance is essential and requires a data source that can reliably capture a wide range of congenital malformations. The UK General Practice Research Database (GPRD) may have the potential to be used for this kind of surveillance. OBJECTIVE: To assess the extent to which this database can be used to accurately identify major congenital malformations. METHODS: This study was carried out as part of a broader study to compare data on anticonvulsant use and safety in pregnancy between the GPRD and a pregnancy registry. The study period ran from 1 January 1990 until 31 December 2006. Mother-baby pairs where the mother had a record of epilepsy, seizure or convulsion were identified using the GPRD computerized medical records. Infants of mother-baby pairs who had a record of a major congenital malformation were identified. Full photocopied paper medical records were requested from the infant's general practitioner and where this was not possible any data entries consisting of uncoded comments, so-called 'free text', in the electronic GPRD record were requested from the database provider. This additional information was then reviewed in order to determine the extent to which the congenital malformation diagnoses identified via the computerized records could be confirmed or rejected and then classified as being major or minor. RESULTS: Within the study population of 3869 live mother-baby pairs, 188 potentially major congenital malformations were identified from the GPRD computerized record relating to 161 unique individuals. Using a combination of photocopied medical records and free text it was possible to verify 160 malformations (85.1%) as the malformation indicated by the computerized records; this ranged from 91.7% of those cases verified using photocopied medical records and 77.9% of cases verified using free text. Of the verified congenital malformations, using a combination of computerized data, photocopied medical records and free text, it was possible to classify 78.1% as being major and 15.0% as minor, and this percentage was found to be the same for those cases reviewed by photocopied records and those where free text was used. The proportions of malformations that could be verified and those that could be classified as major or minor were found to vary by malformation class. CONCLUSIONS: The GPRD can be used to ascertain a wide range of congenital malformations. In many cases, when a malformation is identified in the GPRD via the computerized medical records, the malformation is likely to exist. However, in this study a small proportion of identified cases had to be excluded because they had been coded incorrectly or diagnostically ruled out. Therefore, depending on the congenital malformation of interest, verification of such malformations using photocopied medical records or free text is generally recommended.