Papers by Christine Bredfeldt
Background. Influenza infection during pregnancy is associated with adverse fetal outcomes such a... more Background. Influenza infection during pregnancy is associated with adverse fetal outcomes such as preterm birth and small for gestational age (SGA). Maternal influenza immunization may prevent these adverse infant outcomes during periods of influenza circulation. Methods. We conducted a retrospective cohort study of live births within Kaiser Permanente (KP) Georgia and Mid-Atlantic States (n = 3327) during the period of 2009 influenza A (H1N1) virus circulation. Primary outcomes were third-trimester preterm birth (27-36 weeks), birth weight, low birth weight (LBW, <2500 g), and SGA. Results. There were 327 (9.8%) preterm, 236 (7.4%) LBW, and 267 (8.4%) SGA births. Among H1N1-vaccinated mothers (n = 1125), there were 86 (7.6%) preterm, 68 (6.4%) LBW, and 99 (9.3%) SGA births, and the mean birth weight was 3308.5 g (95% confidence interval [CI], 3276.6-3340.4). Among unvaccinated mothers (n = 1581), there were 191 (12.1%) preterm, 132 (8.8%) LBW, and 123 (8.2%) SGA births, and the mean birth weight was 3245.3 g (95% CI, 3216.5-3274.2). Infants of H1N1-vaccinated mothers had 37% lower odds of being born preterm than infants of unvaccinated mothers (adjusted odds ratio, 0.63 [95% CI, .47-.84]). The mean birth weight difference between infants of H1N1-vaccinated mothers and infants of unvaccinated mothers was 45.1 g (95% CI, 1.8-88.3). There was no significant association between maternal H1N1 influenza immunization and LBW or SGA. Conclusions. Pregnant women who received H1N1 influenza vaccine were less likely to give birth preterm, and gave birth to heavier infants. The findings support US vaccine policy choices to prioritize pregnant women during the 2009 influenza A (H1N1) pandemic.
Background. Influenza infection during pregnancy is associated with adverse fetal outcomes such a... more Background. Influenza infection during pregnancy is associated with adverse fetal outcomes such as preterm birth and small for gestational age (SGA). Maternal influenza immunization may prevent these adverse infant outcomes during periods of influenza circulation. Methods. We conducted a retrospective cohort study of live births within Kaiser Permanente (KP) Georgia and Mid-Atlantic States (n = 3327) during the period of 2009 influenza A (H1N1) virus circulation. Primary outcomes were third-trimester preterm birth (27–36 weeks), birth weight, low birth weight (LBW, <2500 g), and SGA. Results. There were 327 (9.8%) preterm, 236 (7.4%) LBW, and 267 (8.4%) SGA births. Among H1N1-vaccinated mothers (n = 1125), there were 86 (7.6%) preterm, 68 (6.4%) LBW, and 99 (9.3%) SGA births, and the mean birth weight was 3308.5 g (95 % confidence interval [CI], 3276.6–3340.4). Among unvaccinated mothers (n = 1581), there were 191 (12.1%) preterm, 132 (8.8%) LBW, and 123 (8.2%) SGA births, and th...
Behavioral/Systems/Cognitive A Simple Account of Cyclopean Edge Responses in
It has been shown recently that neurons in V2 respond selectively to the edges of figures defined... more It has been shown recently that neurons in V2 respond selectively to the edges of figures defined only by disparity (cyclopean edges). These responses are orientation selective, often preferring similar orientations for cyclopean and luminance contours, suggesting that they may support a cue-invariant representation of contours. Here, we investigate the extent to which processing of purely local visual information (in the vicinity of the receptive field) might explain such results, using themost impoverished stimulus possible containing a cyclopean edge (a circular patch of random dots divided into two regions by a single edge). Many V2 cells responded better to the cyclopean edge than touniformdisparities, andmost of thesewere at least broadly selective for theorientationof the cyclopean edge. Two characteristics argue against a cue-invariant contour representation: (1) the cyclopean edge response was frequently abolished by small changes to the component disparities; and (2) altho...
Dynamics of spatial frequency tuning of macaque LGN
Journal of Vision, 2010
ABSTRACT
The effects of framed messages for engaging adolescents with online smoking prevention interventions
Translational Behavioral Medicine
The projected impact of the baby boomers on the trajectory of and spending on Alzheimer's disease
Alzheimer's & Dementia, 2015
A Review of Patient Reported Outcomes for Diabetic Peripheral Neuropathy
Journal of Diabetes and its Complications, 2015
Multiple patient-reported outcomes (PROs) have been used to assess symptoms among patients with D... more Multiple patient-reported outcomes (PROs) have been used to assess symptoms among patients with Diabetic Peripheral Neuropathy (DPN). However, there is little consistent application of measures in clinical or research settings. Our goal was to identify and compare patient reported outcome measures (PROs) specifically evaluated in neuropathy populations. Literature search, summary, and qualitative comparison of PROs validated in neuropathy populations. We identified 12 studies of PROs evaluated in neuropathy populations that included DPN patients. Two assessed sleep quality, 5 assessed painful symptoms, and 5 assessed quality of life. The number of items per measure ranged from one to 97, and the number of domains ranged from one to 18. All had adequate internal consistency (Chronbach&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s Alpha&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.70). There was mild to moderate standardization of domains across measures and only a few instruments used common comparators. The spectrum of DPN symptoms addressed included: sensory symptoms, autonomic symptoms, and function, beliefs, role participation, sleep quality, and perceptions of illness. There remains a need for a gold standard for DPN symptom assessment. Few existing instruments are adequately validated and the domains assessed are inconsistent. Current instrument selection should depend on the clinical and social context of the assessment.
2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2008
This paper describes the technical evaluation of the Multi-Axis Cartesian-based Arm Rehabilitatio... more This paper describes the technical evaluation of the Multi-Axis Cartesian-based Arm Rehabilitation Machine (MACARM), a cable robot for upper limb rehabilitation. The MACARM was evaluated for static and dynamic positional accuracy, force performance, speed and work volume. Results indicate positional errors smaller than 1% of the movement magnitude, indicating stable performance throughout the tested range. In addition, the MACARM demonstrated favorable path repeatability, a critical element for "teach and play" approaches to robotic rehabilitation. However, measurements indicated a coupling between the end-effector position and orientation, which may impact force performance. In the next phase of this project, we will use the data collected in the technical evaluation to optimize the kinematic model to address this issue.
Journal of Neuroscience, 2006
It has been shown recently that neurons in V2 respond selectively to the edges of figures defined... more It has been shown recently that neurons in V2 respond selectively to the edges of figures defined only by disparity (cyclopean edges). These responses are orientation selective, often preferring similar orientations for cyclopean and luminance contours, suggesting that they may support a cue-invariant representation of contours. Here, we investigate the extent to which processing of purely local visual information (in the vicinity of the receptive field) might explain such results, using the most impoverished stimulus possible containing a cyclopean edge (a circular patch of random dots divided into two regions by a single edge). Many V2 cells responded better to the cyclopean edge than to uniform disparities, and most of these were at least broadly selective for the orientation of the cyclopean edge. Two characteristics argue against a cue-invariant contour representation: (1) the cyclopean edge response was frequently abolished by small changes to the component disparities; and (2) although V2 cells frequently responded to both signs of a cyclopean edge (defined by which side of the edge is in front), they did so at different edge locations. These characteristics are consistent with a simple feedforward scheme in which V2 neurons receive inputs from several V1 subunits with different disparity selectivity. We also found a correlation between the preferred orientations for cyclopean edges and contrast stimuli, suggesting that this feedforward wiring is not random. These characteristics suggest that V2 responses to cyclopean edges may be useful in supporting a cue-invariant contour representation higher in the visual pathway.
Journal of Infectious Diseases, 2012
Background. Pregnant women were at increased risk for serious outcomes of 2009 pandemic influenza... more Background. Pregnant women were at increased risk for serious outcomes of 2009 pandemic influenza A virus subtype H1N1 (influenza A[H1N1]pdm09) infection, but little is known about the overall impact of the pandemic on neonatal and maternal outcomes. Methods. We identified live births that occurred from 1 July 2008 through 31 May 2010 in 5 Kaiser Permanente regions. Pregnant women were considered to have influenza if they had a positive result of a laboratory test for influenza virus or if they received a diagnosis of influenza during a period in which seasonal influenza virus or A(H1N1)pdm09 was the predominant circulating virus. Results. There were 111 158 births from 109 015 pregnancies involving 107 889 mothers; 368 pregnant women (0.3%) received a diagnosis of influenza due to seasonal virus, and 959 (0.9%) received a diagnosis of influenza due to A(H1N1)pdm09; 107 688 did not receive an influenza diagnosis. Pregnant women with influenza due to A(H1N1)pdm09 were more likely than women with seasonal influenza infection to be hospitalized within 30 days of the diagnosis (27% vs 12%; odds ratio [OR], 2.84 [95% confidence interval {CI}, 2.01-4.02]). Pregnant women with A(H1N1)pdm09 who started antiviral treatment ≥2 days after the diagnosis were significantly more likely to be hospitalized than those who started antiviral treatment <2 days after diagnosis (OR, 3.43 [95% CI, 1.55-7.56]). Mothers with seasonal influenza virus infection had an increased risk for having a small-forgestational-age infant (OR, 1.59 [95% CI, 1.15-2.20]). Conclusions. In this large, geographically diverse population, A(H1N1)pdm09 infection increased the risk for hospitalization during pregnancy. Late initiation of antiviral treatment was also associated with an increased risk for hospitalization.
International Journal for Quality in Health Care, 2011
Objective. To determine whether physicians who interact with their patients between office visits... more Objective. To determine whether physicians who interact with their patients between office visits using secure messaging and phone provide better care for patients with diabetes when controlling for physician, patient and care center characteristics. Design. Retrospective study. Setting. Kaiser Permanente Mid-Atlantic States. Participants. 174 Primary Care Physicians. Intervention. We modeled the relationship between communication via secure messaging or phone communication and Diabetes Recognition Program (DRP) scores with a Generalized Estimating Equations model. Covariates included physician age and panel size, patient age, race, income and number of comorbidities, and the population density around the care center. Main Outcome Measure. DRP scores. Results. Physicians whose patients were predominantly white or mixed race were more likely than other physicians to use secure messaging and phone with their patients between visits, but there was no significant association between such contacts and DRP scores (P. 0.1). In contrast, physicians with predominantly black or Hispanic patients had significantly higher DRP scores associated with the use of secure messaging (P , 0.01) and higher, though not statistically significant, DRP scores associated with the use of phone (P , 0.1). These associations were strongest for outcome measures such as HbA1c and lipid levels, and were weaker or nonexistent for process measures such as annual foot and eye exams. Conclusions. The use of secure messaging, and, to a lesser extent, phone, appears to be associated with higher quality diabetes care, particularly among at-risk populations.
Clinical Medicine & Research, 2013
Background/Aims: Because of the distributed nature of dental practice, dentists tend to develop p... more Background/Aims: Because of the distributed nature of dental practice, dentists tend to develop practice patterns based on the training they received in dental school. While their training was current at their graduation, as the period post-graduation increases more recent research holds the potential to improve dental care. Innovative methods are needed to educate dentists in the latest evidence-based approaches to practice. The aim of this study is to build a case-based internet simulation interface to educate dentists on the latest evidence-based approaches to practice. Methods: Due to the complexity of the project it was decided to work on multiple components in parallel. One team was formed to review possible guidelines using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) standards. Insufficient high quality guidelines necessitated examining systematic reviews using an approach based on PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses). A second team began work to develop standards for case creation. A third team of internet programmers began to create the front-and back-end for the case-based interface. Communication between the teams is facilitated by partial shared team membership and the attention of the principal investigator. Results: In order to complete the system within the one year development timeline, we discovered that we needed to make specific compromises to balance the ideal and the practical scenarios. First, each case would involve a single encounter where the provider would be given sufficient information to identify the problems and plan treatments for future encounters. Second, in order to limit the options for gaming the system, all sub-actions will be linked to specific time intervals. Each encounter will then be assigned total completion time based on the sum of the sub-action times. Conclusions: Case-based learning, structured around an internet interface and presented to dentists distributed across small practices throughout the world, should be an important link in educating dentists on uniform evidence-based dental information.
Clinical Medicine & Research, 2013
need for clinic staff to enter data into the EMR and to administer the questionnaire orally when ... more need for clinic staff to enter data into the EMR and to administer the questionnaire orally when the information is needed immediately, we have been evaluating administration using Interactive Voice Response (IVR) and online questionnaire administration. Methods: KP members were invited to participate in the IVR or the online pilot. Some IVR participants were asked to complete the Health Assessment prior to a scheduled Wellness Visit and others were invited to test the IVR system at a research facility. Those at the facility were observed and all participants were interviewed immediately after completing it. For the online pilot, members were emailed the survey link and asked to complete the Health Assessment. Once the Health Assessment was submitted, members were interviewed about their experience. Results: The majority (80%) of IVR participants reported that it took an acceptable amount of time to complete the Health Assessment. Twothirds used a handheld telephone but still 75% reported it was "very easy" to respond to the survey. Nearly all could hear the questions clearly and understand the questions and response options. About 50% of members asked were willing to complete the Health Assessment online. All online participants found it easy to access and complete the Health Assessment using a link emailed to them. Conclusions: Both IVR and online surveys are viable options for administering a health assessment to senior members. Over half of the test respondents would prefer IVR over other modalities. Members who are comfortable with and have access to a computer in their home often prefer the online modality. Although high-tech modalities are feasible and preferable to a segment of the senior population, other modalities need to be available.
Clinical Medicine & Research, 2012
HMORN 2012-Selected Abstracts remain at the local sites; there is no multi-site physical database... more HMORN 2012-Selected Abstracts remain at the local sites; there is no multi-site physical database at a centralized data coordinating center. At the core of the VDW are a series of standardized file definitions. Content areas and data elements that are commonly required for research studies are identified, and data dictionaries are created for each of the content areas, specifying a common format for each of the elements-variable name, label, description, code values, and value labels. Local site programmers have mapped the data elements from their HMO's data systems into this standardized set of variable definitions, names, and codes, as well as onto standardized SAS file formats. This common structure of the VDW files enables a SAS analyst at one site to write one program to extract and/or analyze data at all participating sites. Methods: This poster demonstrates the wide range of data sources used at HealthPartners Research Foundation to feed information into our local implementation of the VDW datasets. Results: The HealthPartners Research Foundation local implementation of the VDW contains detailed medical information on HealthPartners members and patients. These files contain details on 69 million pharmacy dispensings (2000-2011), nearly 58 million unique medical encounters (2000-2011), including 14 million diagnoses, and 20 million procedures. We have some 9 million Vital Signs observations, and 26 million lab results. The VDW Enrollment and Demographic files are derived from several historical and current membership/patient files; the VDW Pharmacy and utilization files are derived from internal HealthPartners systems plus claims files; the VDW tumor data is retrieved from our owned Cancer Registry. Conclusions: The VDW at HealthPartners Research Foundation provides an easily employed unified central repository of data from all available source files. This resource enables the sharing of compatible data in multi-site studies, and also improves programming efficiency, accuracy, and completeness for local single site studies by expending resources to link these legacy systems only once.
Clinical Medicine & Research, 2012
Background/Aims: The Virtual Data Warehouse (VDW) was created as a mechanism for producing compar... more Background/Aims: The Virtual Data Warehouse (VDW) was created as a mechanism for producing comparable data across sites for purposes of proposing and conducting research. It is "virtual" in the sense that the data remain at the local sites rather than at a centralized data coordinating center. At the core of the VDW are a series of standardized file definitions. Content areas and data elements that are commonly required for research studies are identified, and data dictionaries are created for each of the content areas, specifying a common format for each of the elements-variable name, label, description, code values, and value labels. Local site programmers have mapped the data elements from their HMO's data systems into this standardized set of variable definitions, names, and codes, as well as onto standardized SAS file formats. This common structure of the VDW files enables a SAS analyst at one site to write one program to extract and/or analyze data at all participating sites. Methods: This poster demonstrates the range of data sources used at Kaiser Permanente in the Mid-Atlantic States (KPMAS) to feed information into our local implementation of the VDW datasets. Results: The KPMAS local implementation of the VDW contains detailed medical information on KPMAS members. These files contain details on 33 million pharmacy dispensings (2004-2011), nearly 27 million unique medical encounters (2005-2011), including 0.5 million hospitalizations, 19 million ambulatory visits, 80 million diagnoses, and 46 million procedures. The data includes 19 million Vital Signs observations, and 40 million lab results. The VDW Enrollment and Demographic files are derived from several historical and current membership files; the VDW Utilization and Pharmacy files are derived from national Kaiser Permanente systems, augmented with data from the KPMAS electronic health record and claims systems; the VDW tumor data is derived from MD, VA and DC state registries. Conclusions: The KPMAS VDW provides a centralized, tested repository of data from all available sources. This resource enables data sharing for multi-site studies, and also improves programming efficiency, accuracy, and completeness for KPMAS studies by providing an integrated regional data warehouse.
Clinical Medicine & Research, 2012
HMORN 2012-Selected Abstracts also appear in another site's data. Most notably-the protocol does ... more HMORN 2012-Selected Abstracts also appear in another site's data. Most notably-the protocol does not call for transmitting any unencrypted PHI. The core of the method involves the repeated use of a commutative cipher to encrypt identifiers, each site using its own key, and then comparing the results for overlaps. The end result of the protocol is that each site will know which of its MRNs represent people who also appear in other sites' data, and which site(s) those are. The presentation will describe the data flows, algorithms and processes necessary to create this data. Results: The protocol described can be run once to assess the actual overlap, and-if it is significant enoughperiodically to create this data at the sites. Once created, the data could be made part of the VDW, allowing HMORN projects to easily assure that each person in each distributed cohort appeared in only one site's file. Conclusions: Being able to say that we have actually investigated population overlap and either found it in fact to be negligible, or that we have a method for de-duplicating people is far preferable to hand-waving and bare assertions that any overlap must be insignificant. As the HMORN grows and VDW collaborators become more numerous, we should expect this question to take on more and more significance in the eyes of both our funders and the consumers of our research.
Clinical Medicine & Research, 2012
HMORN 2012-Selected Abstracts also appear in another site's data. Most notably-the protocol does ... more HMORN 2012-Selected Abstracts also appear in another site's data. Most notably-the protocol does not call for transmitting any unencrypted PHI. The core of the method involves the repeated use of a commutative cipher to encrypt identifiers, each site using its own key, and then comparing the results for overlaps. The end result of the protocol is that each site will know which of its MRNs represent people who also appear in other sites' data, and which site(s) those are. The presentation will describe the data flows, algorithms and processes necessary to create this data. Results: The protocol described can be run once to assess the actual overlap, and-if it is significant enoughperiodically to create this data at the sites. Once created, the data could be made part of the VDW, allowing HMORN projects to easily assure that each person in each distributed cohort appeared in only one site's file. Conclusions: Being able to say that we have actually investigated population overlap and either found it in fact to be negligible, or that we have a method for de-duplicating people is far preferable to hand-waving and bare assertions that any overlap must be insignificant. As the HMORN grows and VDW collaborators become more numerous, we should expect this question to take on more and more significance in the eyes of both our funders and the consumers of our research.
Clinical Medicine & Research, 2012
Clinical Medicine & Research, 2012
HF-related chart reviews and for possible early detection of HF. In addition, the integrated NLP ... more HF-related chart reviews and for possible early detection of HF. In addition, the integrated NLP components and our validation methodology can be adapted for application beyond HF.
Clinical Medicine & Research, 2012
HMORN 2012-Selected Abstracts procedure was CT scan, of which 132 (32%)were potentially redundant... more HMORN 2012-Selected Abstracts procedure was CT scan, of which 132 (32%)were potentially redundant, for a rate of 7.4% (5.0-10.6%) per 100,000 member months. Rates will be calculated for a similar period following the HIE implementation and compared to baseline rates to assess the impact. Discussion: The HIE represents a new tool that can potentially reduce the rates of redundant testing in the ED setting. The process of defining redundant tests is a critical component of this kind of analysis. More work is needed in this area to define, standardize, and validate the "rules" for categorizing tests as redundant.
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Papers by Christine Bredfeldt