Low hemoglobin increases risk for cerebrovascular disease, kidney disease, pulmonary vasculopathy, and mortality in sickle cell disease: A systematic literature review and meta-analysis

Sickle cell disease (SCD) is characterized by deoxygenation-induced polymerization of hemoglobin in red blood cells, leading to hemolytic anemia, vaso-occlusion, and the development of multiple clinical complications. To characterize the clinical burden associated with differences in hemoglobin concentration and hemolysis measures, a systematic literature review of MEDLINE, EMBASE, and related meta-analyses was undertaken. For quantitative analyses related to hemoglobin concentration, pooled results were analyzed using random effects models to control for within-and between-study variability. To derive risk ratios associated with hemoglobin concentration change, we combined ratios of means from select studies, which reported hazard and odds ratios in meta-analyses for hemoglobin concentration-related outcomes and changes between groups. Forty-one studies were identified for inclusion based on relating hemoglobin concentration to clinical outcomes. Meta-analyses demonstrated that mean hemoglobin concentration was significantly lower in patients with cerebrovascular disease (0.4 g/dL), increased transcranial Doppler velocity in cerebral arteries (0.6 g/dL), albuminuria (0.6 g/dL), elevated estimated pulmonary artery systolic pressure (0.9 g/dL), and in patients that subsequently died (0.6 g/dL). In a risk reduction meta-analysis, modeled increased hemoglobin concentrations of 1 g/dL or greater resulted in decreased risk of negative clinical outcomes of 41% to 64%. In conclusion, chronic anemia is associated with worse clinical outcomes in individuals with SCD and even modest increases in hemoglobin concentration may be beneficial in this patient population. This systematic review has been registered on Prospero (Registration number CRD42018096860; https://www.crd.york.ac.uk/prospero/).

Patient-reported outcomes in moderate-to-severe allergic asthmatics treated with omalizumab: a systematic literature review of randomized controlled trials

OBJECTIVE

Randomized controlled trials (RCTs) have established the safety and efficacy of omalizumab on clinical parameters, and have also evaluated its impact on patient-reported outcomes (PROs). The purpose of this systematic literature review was to review published data based on PRO endpoints in order to determine the benefit of omalizumab as add-on therapy to inhaled corticosteroids in patients with moderate-to-severe persistent allergic asthma.

METHODS

A systematic literature review was conducted of reference databases and recent conferences. RCTs of add-on omalizumab therapy in adults, adolescents, and children with moderate-to-severe persistent asthma were included. Two researchers independently screened and reviewed articles with regards to inclusion and exclusion criteria for relevant studies.

RESULTS

Twenty-six trials met the criteria for inclusion. Of these, PRO measures were included in 19 trials to capture the impact of omalizumab on symptoms, 11 assessed patients for health-related quality-of-life (HRQoL), and four evaluated asthma control. Other PROs related to global evaluation of treatment effectiveness and work productivity. Overall, results demonstrated a significant difference across most PROs in favor of omalizumab add-on therapy vs placebo or comparators.

CONCLUSIONS

PROs are an integral part of outcome assessment in clinical trials related to asthma. The RCTs reviewed demonstrate that omalizumab treatment improves PROs in patients with moderate-to-severe persistent allergic asthma, particularly symptom control and HRQoL.

Efficacy and safety of omalizumab in children and adolescents with moderate-to-severe asthma: A systematic literature review

BACKGROUND

There are limited pediatric data about the use of omalizumab, especially the effectiveness and safety of omalizumab in the real-world management of allergic asthma.

OBJECTIVE

The objective of this study was to summarize the safety and efficacy of omalizumab in both randomized clinical trials (RCT) used for U.S. Food and Drug Administration registration and real-world studies (RWS) based on clinical care of children with moderate-to-severe asthma.

METHODS

Studies that evaluated omalizumab use in patients <18 years old and with asthma, published between January 2003 and October 2016, were retrieved from medical literature data bases. Assessed outcomes included the following: exacerbation rates, spirometric indices, changes in asthma medication use, asthma control, patient-reported outcomes, and health care resource utilization.

RESULTS

A total of five RWS were identified; outcomes reported were compared with three omalizumab RCTs. Overall, the mean rate of annual exacerbations was significantly lower after 6 months to 2 years of treatment with omalizumab in both RCTs and RWS. In two RCTs and three RWS, inhaled corticosteroid use was significantly reduced in patients who used omalizumab. Similar reductions in the use of rescue medication were also observed in the RCTs and RWS on omalizumab. Real-world evidence demonstrated improvement in forced expiratory volume in the first second of expiration (% predicted) in patients treated with omalizumab as well as significant improvement in the level of asthma control observed over 1 year. There also was evidence that omalizumab treatment reduced health care resource utilization, including fewer hospitalizations, emergency department visits, and unscheduled medical visits. Safety outcomes in all five RWS showed no new safety signals and demonstrated that omalizumab was well tolerated.

CONCLUSION

Overall, RCT evidence strongly supported omalizumab efficacy and safety as add-on treatment in children 6 to 11 years old with moderate-to-severe persistent allergic asthma. RWS data confirmed these findings in an extended patient population of children and adolescents that is more generalizable to the actual day-to-day management of these patients.

Biomarker tests for the diagnosis of Alzheimer's disease: Generating evidence to inform insurance coverage determinations

Outside of their uses in drug development and clinical research trials, the current clinical value of performing any type of formal biomarker testing for the diagnosis or exclusion of Alzheimer's disease (AD) is controversial, and most biomarker tests for AD are not covered by public or private insurers. This situation raises the issue of how insurers determine whether there is "adequate" evidence to justify a positive coverage determination in this area. This article, a focused condensation of a larger white paper, is the product of an initiative led by the Institute for Clinical and Economic Review to convene a multiple-stakeholder AD Diagnostics Policy Development Group composed of patient advocates, clinicians, clinical researchers, manufacturers, and insurers. The larger white paper was the basis for the evidence review presented to the Medicare Evidence Development and Coverage Advisory Committee meeting on January 30, 2013, as part of its deliberations on positron emission tomography-amyloid imaging. Herein we focus on the description of the core elements of what insurers will be looking for in evidence on all potential diagnostic tests for AD. Corresponding research recommendations are also included, framed to serve as a guide for future AD diagnostics research.

Patient Satisfaction with Warfarin- and Non–Warfarin-Containing Thromboprophylaxis Regimens for Atrial Fibrillation

Objective

To compare patient-reported limitations, concerns, and burdens in those receiving and not receiving warfarin for thromboprophylaxis in atrial fibrillation (AF).

Methods

We conducted a cross-sectional survey study of patients with AF receiving thromboprophylaxis for stroke prevention. Patients were administered the validated Anti-Clot Treatment Scale (ACTS). Mean scores of patients receiving and not receiving warfarin were compared for each ACTS item, and for the Burden and Benefit subscales.

Results

From July 2010 to August 2011, 80 patients with AF were administered the survey, with 65 patients receiving a regimen containing warfarin and 15 patients not receiving a regimen containing warfarin. Six of the 17 individual questions depicting patient- perceived limitations in physical activity due to bleeding, limitations on diet, feelings of inconvenience of occasional aspects of thromboprophylaxis therapy, and frustration, and burden had less favorable scores in the warfarin-managed patients compared with the patients not receiving warfarin ( P < 0.05 for all). Mean ACTS Burden scores were more favorable in the no-warfarin group (44.5 ± 6.4) compared with the warfarin group (39.8 ± 8.0; P = 0.003). No difference was seen between the 2 groups on the ACTS Benefits score (11.1 ± 3.4 vs 10.4 ± 3.7; P = 0.38).

Conclusion

Patients with AF receiving warfarin may have less favorable feelings regarding thromboprophylaxis versus those receiving non-warfarin thromboprophylaxis. Patients report having more limitations and having greater feelings of burden on warfarin.

Management options for children with attention-deficit/hyperactivity disorder: a regional perspective on value

Use of comparative effectiveness information in local healthcare decisions can be confounded by variations in practice, barriers to access and population demographics. The New England Comparative Effectiveness Public Advisory Council was convened as a public deliberative panel that considers evidence on the comparative clinical effectiveness and comparative value of a variety of therapeutic interventions. The council is tasked with making summary judgments on the evidence and recommendations for applying the evidence in medical and drug coverage policy, as well as initiating educational efforts for patients and clinicians. The New England Comparative Effectiveness Public Advisory Council met in June 2012 to discuss management options for attention-deficit/hyperactivity disorder, guided by a recent comparative effectiveness review from the Agency for Healthcare Research and Quality and supplementary economic analyses conducted by the Institute for Clinical and Economic Review. This article summarizes the deliberations and reflects on lessons learned regarding use of region-specific economic analyses to guide decision-making.

Factors associated with 'caregiver burden' for atrial fibrillation patients

BACKGROUND

The burden on caregivers providing support to atrial fibrillation (AF) patients has not been evaluated.

OBJECTIVE

To examine the interrelationship between unpaid caregiver, patient and thromboprophylaxis characteristics and caregiver burden in AF.

METHODS

We conducted a cross-sectional survey study of AF patient-caregiver dyads recruited from cardiology clinics at an urban teaching hospital. Eligible patients had a diagnosis of AF, received thromboprophylaxis to prevent stroke, lived in the community and had an adult, unpaid, English-speaking caregiver. Hierarchical multivariate regression was used to evaluate the association between caregiver, patient and thromboprophylaxis characteristics and caregiver burden as measured by the 'Caregiver Reaction Assessment' (CRA).

RESULTS

Eighty patient-caregiver dyads were surveyed. The mean ± standard deviation scores for each CRA domain were 'Disrupted schedule' (2.4 ± 1.0), 'Financial problems' (2.1 ± 0.8), 'Lack of family support' (1.9 ± 0.7), 'Health problems' (1.9 ± 0.7) and 'Self-esteem' (0.9 ± 0.5). Significantly greater caregiver burden due to 'Disrupted schedule' was seen in those spending > 4 h/week providing care and when caring for frail, sick or disabled patients, with higher CHADS2 scores and requiring help with their medications. 'Financial problems' burden scores were significantly associated with caring for frail patients and those requiring more frequent office follow-up. 'Lack of family support' scores were inversely associated with having somebody else to help provide care and increased as patients CHADS2 score increased. Lower 'Health problem' burden scores were associated with female gender and higher scores with the need to spend > 4 h/week providing care.

CONCLUSION

The greatest burden to caregivers of AF patients occurs due to schedule disruption.

Neurothrombectomy devices for the treatment of acute ischemic stroke: state of the evidence

BACKGROUND

Acute ischemic strokes are associated with poor outcomes and high health care burden. Evidence exists evaluating the use of neurothrombectomy devices in patients receiving currently recommended treatments that may have limited efficacy.

PURPOSE

To describe the state of the evidence supporting use of neurothrombectomy devices in the treatment of acute ischemic stroke.

DATA SOURCES

MEDLINE, SCOPUS, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Web of Science were searched, without language restrictions, from their inception through May 2010. The MEDLINE and Cochrane Central Register of Controlled Trials searches were updated through November 2010.

STUDY SELECTION

Two independent investigators screened citations for human studies of any design or case series or case reports of patients with an acute ischemic stroke that evaluated a neurothrombectomy device and reported at least 1 clinical effectiveness outcome or harm.

DATA EXTRACTION

Using standardized protocols, 2 independent investigators extracted information about study characteristics and outcomes, and a third reviewer resolved disagreement.

DATA SYNTHESIS

87 articles met eligibility criteria, including 18 prospective single-group studies, 7 noncomparative retrospective studies, and 62 case series or case reports. Two U.S. Food and Drug Administration (FDA)-cleared devices, the MERCI Retriever (Concentric Medical, Mountain View, California) (40%) and the Penumbra System (Penumbra, Alameda, California) (9%), represented a large portion of the available data. All prospective and retrospective studies provided data on successful recanalization with widely varying rates (43% to 78% with the MERCI Retriever and 83% to 100% with the Penumbra System). Rates of harms, including symptomatic (16 studies; 0% to 10% with the MERCI Retriever and 0% to 11% with the Penumbra System) or asymptomatic (13 studies; 28% to 43% and 1% to 30%, respectively) intracranial hemorrhage and vessel perforation or dissection (11 studies; 0% to 7% and 0% to 5%, respectively), also varied by device. Predictors of harm included older age, history of stroke, and higher baseline stroke severity scores, whereas successful recanalization was the sole predictor of good outcomes.

LIMITATIONS

Most available data are from single-group, noncomparative studies. In addition, the patient population most likely to benefit from these devices is undetermined.

CONCLUSION

Currently available neurothrombectomy devices offer intriguing treatment options in patients with acute ischemic stroke. Future trials should use a randomized design, with adequate power to show equivalency or noninferiority between competing strategies or devices, and strive to identify populations that are most likely to benefit from use of neurothrombectomy devices.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Study of magnetic fields from power-frequency current on water lines

The magnetic fields from power-frequency current flowing on water lines were investigated in a new approach that involved an area-wide survey in a small town. Magnetic fields were measured outside the residence under power cables and over water lines, and each residence was characterized as to whether it received water from a private well or the municipal water system. The magnetic field data revealed two statistical modes when they were related to water supply type. The data also showed that in the case of the high mode, the magnetic field remained constant along the line formed by power drop wires, at the back of the house, and the water hookup service, in front of the house, all the way to the street. The patterns are explained by the coincidence of measurement points and the presence of net current flowing on power mains, power drop conductors, residential plumbing, water service hookups, and water mains. These patterns, together with other characteristics of this magnetic field source, such as the gradual spatial fall-off of this field and the presence of a constant component in the time sequence, portray a magnetic field more uniform and constant in the residential environment than has been thought to exist. Such characteristics make up for the weakness of the source and make net current a significant source of exposure in the lives of individuals around the house, when human exposure to magnetic fields is assumed to be a cumulative effect over time. This, together with the bimodal statistical distribution of the residential magnetic field (related to water supply type), presents opportunities for retrospective epidemiological analysis. Water line type and its ability to conduct power-frequency current can be used as the historical marker for a bimodal exposure inference, as Wertheimer et al. have shown.