Allyson M Abrams's research while affiliated with Harvard Pilgrim Health Care and other places

Publications (35)

Article
Full-text available
Background Detecting outbreaks is a crucial task for public health officials, yet gaps remain in the systematic evaluation of outbreak detection protocols. The authors’ objectives were to design, implement, and test a flexible methodology for generating detailed synthetic surveillance data that provides realistic geographical and temporal clusterin...
Article
Full-text available
Passive reporting and laboratory testing delays may limit gastrointestinal (GI) disease outbreak detection. Healthcare systems routinely collect clinical data in electronic medical records (EMRs) that could be used for surveillance. This study's primary objective was to identify data streams from EMRs that may perform well for GI outbreak detection...
Article
Full-text available
The spatial and space-time scan statistics are commonly applied for the detection of geographical disease clusters. Monte Carlo hypothesis testing is typically used to test whether the geographical clusters are statistically significant as there is no known way to calculate the null distribution analytically. In Monte Carlo hypothesis testing, simu...
Conference Paper
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BACKGROUND Modern public health surveillance systems have great potential for improving public health. However, evaluating the performance of surveillance systems is challenging because examples of baseline disease distribution in the population are limited to a few years of data collection. Agent-based simulations of infectious disease transmissio...
Article
To examine how enrollment in high-deductible health plans (HDHPs) affects use of well-child visits relative to traditional plans, when preventive care is exempt from the deductible. Pre-post comparison between groups. We selected children aged <18 years enrolled in a large Massachusetts health plan through employers offering only 1 type of plan. Ch...
Article
Uncontrolled asthma leads to preventable morbidity and increased health care utilization. The authors examined trends, predictors, and costs of uncontrolled asthma over 5 years in a large health plan population. The authors retrospectively examined administrative health claims data from mid-2000 to mid-2007 on patients with asthma aged 1 to 56 year...
Article
Full-text available
Syndromic surveillance systems can potentially be used to detect a bioterrorist attack earlier than traditional surveillance, by virtue of their near real-time analysis of relevant data. Receiver operator characteristic (ROC) curve analysis using the area under the curve (AUC) as a comparison metric has been recommended as a practical evaluation to...
Article
Full-text available
Surveillance for influenza and influenza-like illness (ILI) is important for guiding public health prevention programs to mitigate the morbidity and mortality caused by influenza, including pandemic influenza. Nontraditional sources of data for influenza and ILI surveillance are of interest to public health authorities if their validity can be esta...
Article
In modern surveillance of public health, data may be reported in a timely fashion and include spatial data on cases in addition to the time of their occurrence. This has lead to many recent developments in statistical methods to detect events of public health importance. However, there has been relatively little work about how to compare such metho...
Data
Full-text available
SAS code for SMAC macro. This section contains the SAS code for the SMAC macro described in this paper.
Data
Sample cluster output from SaTScan. Most of the information about each cluster is available in column format from SaTScan, as seen here. Note that in the text file that SaTScan produces, there are no column headings.
Data
SAS code for map macro. This section contains the SAS code for the map macro described in this paper.
Data
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Parameter file generated by parameters macro. This is an example of a typical parameter file generated from the parameters macro.
Data
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Sample text output from SaTScan. This is a sample text file generated as output from SaTScan. It contains detailed information about each cluster, as well as a summary of the parameters that were used to obtain these results.
Data
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SAS code for inputdata macro. This section contains the SAS code for the inputdata macro described in this paper.
Data
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Sample GIS output from SaTScan. SaTScan also creates a text file with mapping information for use with GIS software. Here is an example. Again, note that there are no column headings in the SaTScan output.
Data
SAS macro to run SMAC package. This is a sample SAS macro which can be used to run the SMAC package many times.
Data
SAS code for parameters macro. This section contains the SAS code for the parameters macro described in this paper.
Article
Full-text available
SaTScan is a software program written to implement the scan statistic; it can be used to find clusters in space and/or time. It must often be run multiple times per day when doing disease surveillance. Running SaTScan frequently via its graphical user interface can be cumbersome, and the output can be difficult to visualize. The SaTScan Macro Acces...
Article
Full-text available
Monitoring ongoing processes of illness to detect sudden changes is an important aspect of practical epidemiology and medicine more generally. Most commonly, the monitoring has been restricted to a unidimensional stream of data over time. In such situations, analytic results from the industrial process monitoring have suggested optimal approaches t...
Article
Since the anthrax attacks of October 2001 and the SARS outbreaks of recent years, there has been an increasing interest in developing surveillance systems to aid in the early detection of such illness. Systems have been established which do this is by monitoring primary health-care visits, pharmacy sales, absenteeism records, and other non-traditio...
Article
Full-text available
Data are scarce regarding the sociodemographic predictors of antenatal and postpartum depression. This study investigated whether race/ethnicity, age, finances, and partnership status were associated with antenatal and postpartum depressive symptoms. 1662 participants in Project Viva, a US cohort study. Mothers indicated mid-pregnancy and six month...
Article
Full-text available
OBJECTIVE Our goal was to increase the precision of the p-value produced from SaTScan [1] while reducing the amount of CPU time needed by decreasing the number of Monte Carlo replicates. BACKGROUND SaTScan is a freely available software that uses the scan statistic to detect clusters in space, time or space-time [2]. SaTScan uses Monte Carlo hypoth...
Article
Full-text available
OBJECTIVE We sought to compare ambulatory care (AC) and emergency department (ED) data for the detection of clusters of lower gastrointestinal illness, using AC and ED data and AC+ED data combined, from two geographically separate health plans participating in the National Bioterrorism Syndromic Surveillance Demonstration Program [1].
Article
Full-text available
We measured sensitivity and timeliness of a syndromic surveillance system to detect bioterrorism events. A hypothetical anthrax release was modeled by using zip code population data, mall customer surveys, and membership information from HealthPartners Medical Group, which covers 9% of a metropolitan area population in Minnesota. For each infection...
Article
Full-text available
Multiple systems have been developed that use surveillance of health-care encounters to provide early warning of a terrorist attack. Limited practical experience and the absence of adequate theoretical assessments have precluded determining which alarm-generating algorithms should be preferred. In the absence of practical and theoretical results, c...
Article
Syndromic surveillance systems can be useful in detecting naturally occurring illness. Syndromic surveillance performance was assessed to identify an early and severe influenza A outbreak in Denver in 2003. During October 1, 2003-January 31, 2004, syndromic surveillance signals generated for detecting clusters of influenza-like illness (ILI) were c...
Article
Syndromic surveillance's capability to augment existing surveillance for community-acquired gastrointestinal disease is unknown. The objective of this study was to evaluate the capability of a syndromic surveillance system to detect outbreaks of gastrointestinal disease. A retrospective analysis was conducted comparing ambulatory care data from a h...
Article
Full-text available
The space-time scan statistic is often used to identify incident disease clusters. We introduce a method to adjust for naturally occurring temporal trends or geographical patterns in illness. The space-time scan statistic was applied to reports of lower respiratory complaints in a large group practice. We compared its performance with unadjusted po...

Citations

... For example, including the culture site or antibiotic resistance was shown to boost detectability. Past simulation based approaches [4] tackle optimal surveillance system design, by choosing clinics as sensors, to increase sensitivity and time to detection for outbreaks in a population. In contrast, our approach selects most vulnerable people and locations to infections as sensors to detect outbreaks in a hospital setting. ...
... Although the literature has occasionally highlighted the importance of timing in electronic surveillance systems, no one has linked the temporal dependence of performance metrics and intervention feasibility to the failure of such warning systems and explained how to operationalize timing in their development. [5][6][7][8] Using sepsis as an example, we explain why timing is important and propose new metrics and strategies for training and evaluating EWS models. EWSs are divided into two types: detection systems that recognize critical illnesses at a particular moment and prediction systems that estimate risk of deterioration over varying time frames. ...
... The key objective of surveillance is to offer information to guide interventions. [48] The surveillance system of HCV should set its objectives to: monitor secular trends and detect the high risk groups, detect epidemics, evaluate interventions and monitor preventive measures. Also, it should be able to monitor changes in HCV and also generate hypotheses for future research. ...
... A third limitation of SaTScan™ is the lack of cartographic output [32], while this can be addressed though the use of an external macro [32], an integrated map as the one available in FGBASE, increases the ease of use when viewing clusters. Finally a fourth limitation of SaTScan™, is that it addresses only cluster searches and not the testing of environmental factors. ...
... Use of electronic medical record data from ambulatory care settings for syndromic surveillance, which might capture more episodes of illness-and possibly in earlier stages-is less common. Analyses using diagnostic codes from ambulatory care episodes and from ED episodes from the same overall patient population yield different sets of signals, 9,10 and one data source may be better than the other for detecting some outbreaks of naturally occurring disease. ...
... Clearly, analysis of free-text fields to identify trends and patterns in data over time can be a time-consuming and difficult task. Other analyses of influenzarelated healthcare syndromic surveillance data have used software systems that map symptoms to syndromes [18][19][20][21][22] or used a decision support system or natural language processing tool to categorise all calls [1,2,17,23,24]. Week number influenza season National ILI rate per 100,000 population Currently, there is no facility for mapping of patient symptoms to syndromes or clinical coding -e.g. ...
... Typically, R = 999 replications are made, which means that the computational cost is increased almost a thousandfold over calculating the statistic on just the observed data. As proposed by Abrams et al. (2006), this cost can be reduced significantly by simulating only a smaller number of scan statistics and fitting a Gumbel distribution to these replicates. A P -value can then be calculated as the tail probability of the observed scan statistic for the fitted distribution. ...
... Space-time cluster analysis was carried out using the SaTScan (version 9.6 free available, http://www.satscan.org), which is commonly used to detect space and space-time clusters in public health sectors (23,24). A space-time permutation model was selected to assess the space-time cluster occurrence as only reported cases were available, but not the pig-at-risk population data for ASF was available (24). ...
... 2 Example applications of EHR data include population-level epidemiological studies, 3-5 machine learning-based diagnostic assistants for clinicians, 6 screening for child maltreatment and family violence, 7 and detecting and tracking infectious disease outbreaks. 8,9 However, conclusions rely on the reliability and accuracy of EHR data, which is not guaranteed. 10,11 Indeed, the use of EHR data beyond its original purpose (clinical care and billing) raises specific challenges. ...
... These actions have been associated with short-term morbidity among low-income members (17)(18)(19) but no apparent increases in longer-term adverse macrovascular outcomes, such as myocardial infarction or stroke, in an overall population with diabetes (20). Studies have also demonstrated that exempting preventive services from cost sharing under HDHPs preserves use in the short-term (19,(21)(22)(23)(24)(25). ...