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David P Greenberg - One of the best experts on this subject based on the ideXlab platform.
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estimating the effectiveness of tetanus diphtheria acellular pertussis vaccine
The Journal of Infectious Diseases, 2015Co-Authors: Michael D Decker, Phillip Hosbach, David R Johnson, Vitali Pool, David P GreenbergAbstract:To The Editor—We read with interest Koepke et al's analysis [1] of Wisconsin Immunization Registry (WIR) and pertussis surveillance databases to determine effectiveness of tetanus-diphtheria-acellular pertussis (Tdap) vaccines. We are familiar with the challenges involved in using such data sources to evaluate the performance of pertussis vaccines, as we have been collaborating since 2008 in a multiyear study to evaluate the effectiveness of pediatric pertussis vaccines in Wisconsin (clinical trials registration NCT01129362). The authors are to be commended both for their report and for their enumeration therein of many of the limitations of this nonrandomized, nonprospective study that relies on data collected for administrative purposes. Although their analyses controlled for a number of known confounding factors, we are concerned that their brand-specific analyses were unable to control for potent confounding factors, rendering those analyses unreliable. The full study cohort consisted of WIR clients born during 1998–2000; cases during 2012 were identified and rates calculated by year of Tdap vaccination. However, as shown in Figure 1 of their article, the number of Wisconsin organizations contributing data to the WIR rose from <1000 in 2008 to <1400 in 2011, compared with nearly 2000 in 2013. In addition, brand names plus lot numbers were provided for only 53% of those records (for 20% of Tdap vaccinees, no brand information was available). Moreover, because immigrants to Wisconsin were added to the WIR but emigrants from Wisconsin commonly were not deleted, the WIR database cohort was 21% larger than the actual Wisconsin population size. To provide an alternate analytical population that avoided some of these limitations, a Tdap cohort was constructed, consisting of members of the full cohort documented to have received Tdap during 2008–2011. For sensitivity analyses, missing brand information was imputed on the basis of available information under the missing-at-random assumption. Confounding occurs when a third, unmeasured variable is associated both with the risk factor of interest (eg, Tdap brand information) and the outcome (eg, pertussis) [2]. For example, the association between sex and lung cancer is confounded by the fact that men smoke more than women; smoking correlates with both sex (the putative risk factor) and lung cancer (the outcome). Because of the particular circumstances of Wisconsin with respect to both Tdap brand use and WIR participation and accuracy, the attempt to use the WIR to evaluate pertussis incidence by Tdap brand suffers from multiple confounders. Wisconsin is characterized by many small practices, along with a few very large institutions that predominate in a given subregional or cross-regional area; these providers typically use only 1 brand of Tdap. The likelihood of participating in the WIR and the likelihood of accurate data entry varied by institution and thus varied by geographic location. Relative market share of the 2 Tdap brands varied markedly during the study period and between private and public markets. There were issues for both private and public supplies of Tdap during the study period that led to unplanned changes in the Tdap brand used at various practices, increasing the likelihood of misreporting and miscategorization. A partial list of the confounding correlations includes geographic location and Tdap brand use, geographic location and accuracy and completeness of recording, practice and Tdap brand use, practice and likelihood or accuracy of WIR reporting, year and accuracy and completeness of WIR reporting, Tdap brand use and year, and likelihood of having left Wisconsin and year (and thus Tdap brand). The authors' analyses controlled for Wisconsin region, but these variations in practice behavior (eg, Tdap choice and WIR participation) did not respect regional boundaries, and many of these other confounders are beyond adequate control on the basis of available WIR data. Why does this matter? Consider that if a large institution used only a single brand of pertussis vaccine and that the large institution also was an early and faithful user of WIR (and we know that both of these suppositions are valid), then the WIR size (the denominator for rate calculations) is overrepresented with reports of use of that brand, thus lowering the apparent relative risk of pertussis for that brand. And this is only one of many such examples. Moreover, it is clear that brand misclassification might indeed be differential and that the missing-at-random assumption, used to impute the missing brand information, was not valid. Many of the considerations raised above do not apply to the primary study result, which describes the overall effectiveness of Tdap vaccine against pertussis. Regarding the brand-specific estimates, however, we strongly agree with the authors that their “VE estimates may be biased or confounded by uncontrolled client-level factors” (pp. 949–950 [1]).
Mohamed F Jalloh - One of the best experts on this subject based on the ideXlab platform.
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data on the implementation of vaxtrac electronic Immunization Registry in sierra leone
Data in Brief, 2020Co-Authors: Apophia Namageyofuna, Mohamed F Jalloh, Brigette Gleason, Aaron S Wallace, Michael Friedman, Tom Sesay, Dennis Ocansey, Leora R Feldstein, Laura ConklinAbstract:Abstract Following the piloting of VaxTrac, an electronic Immunization Registry (EIR), we conducted a rapid assessment in November-December 2017 to evaluate the use of the EIR in 10 health facilities in Western Area Urban district in Sierra Leone [1] . In this data-in-brief report, we provide additional descriptive data from the assessment of the VaxTrac EIR in Sierra Leone. The assessment comprised aggregate data on vaccine doses administered that were abstracted from VaxTrac and three paper-based sources (daily tally sheets, register of children under the age of 2 years, and a summary form of doses administered). Data were abstracted for the following six vaccine doses in the Immunization schedule in Sierra Leone: 1) Bacillus Calmette–Guerin vaccine, 2) first dose of pentavalent vaccine, 3) second dose of pentavalent vaccine, 4) third dose of pentavalent vaccine, 5) first dose of measles-containing vaccine, and 6) second dose of measles-containing vaccine. We descriptively analysed the abstracted data to examine the congruity between VaxTrac records and the three paper-based sources. Bar graphs were generated to visually depict the variations in number of administered vaccine doses by data source for each health facility. We provide the aggregated data for each vaccine dose abstracted by data source from each health facility as supplemental material (Excel file). The supplementary data reveal patterns in the congruity of vaccine doses captured that have implications for policy and programmatic decisions regarding the use of VaxTrac and other similar EIRs in low resource urban settings.
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assessment of vaxtrac electronic Immunization Registry in an urban district in sierra leone implications for data quality defaulter tracking and policy
Vaccine, 2020Co-Authors: Apophia Namageyofuna, Mohamed F Jalloh, Brigette Gleason, Aaron S Wallace, Michael Friedman, Tom Sesay, Dennis Ocansey, Leora R Feldstein, Laura ConklinAbstract:Abstract Background In 2016, the Sierra Leone Ministry of Health and Sanitation (MoHS) piloted VaxTrac, an electronic Immunization Registry (EIR), in an urban district to improve management of vaccination records and tracking of children who missed scheduled doses. We aimed to document lessons learned to inform decision-making on VaxTrac and similar EIRs’ future use. Methods Ten out of 50 urban health facilities that implemented VaxTrac were purposively selected for inclusion in a rapid mixed-method assessment from November to December 2017. For a one-month period, records of six scheduled vaccine doses among children Results Overall, VaxTrac captured Conclusion Although VaxTrac helped to shorten the time to manage, summarize, and report vaccination records, data sharing restrictions coupled with inconsistent and inefficient workflows were major implementation challenges. Readiness-to-introduce and sustainability should be carefully considered before implementing an EIR.
Michael D Decker - One of the best experts on this subject based on the ideXlab platform.
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estimating the effectiveness of tetanus diphtheria acellular pertussis vaccine
The Journal of Infectious Diseases, 2015Co-Authors: Michael D Decker, Phillip Hosbach, David R Johnson, Vitali Pool, David P GreenbergAbstract:To The Editor—We read with interest Koepke et al's analysis [1] of Wisconsin Immunization Registry (WIR) and pertussis surveillance databases to determine effectiveness of tetanus-diphtheria-acellular pertussis (Tdap) vaccines. We are familiar with the challenges involved in using such data sources to evaluate the performance of pertussis vaccines, as we have been collaborating since 2008 in a multiyear study to evaluate the effectiveness of pediatric pertussis vaccines in Wisconsin (clinical trials registration NCT01129362). The authors are to be commended both for their report and for their enumeration therein of many of the limitations of this nonrandomized, nonprospective study that relies on data collected for administrative purposes. Although their analyses controlled for a number of known confounding factors, we are concerned that their brand-specific analyses were unable to control for potent confounding factors, rendering those analyses unreliable. The full study cohort consisted of WIR clients born during 1998–2000; cases during 2012 were identified and rates calculated by year of Tdap vaccination. However, as shown in Figure 1 of their article, the number of Wisconsin organizations contributing data to the WIR rose from <1000 in 2008 to <1400 in 2011, compared with nearly 2000 in 2013. In addition, brand names plus lot numbers were provided for only 53% of those records (for 20% of Tdap vaccinees, no brand information was available). Moreover, because immigrants to Wisconsin were added to the WIR but emigrants from Wisconsin commonly were not deleted, the WIR database cohort was 21% larger than the actual Wisconsin population size. To provide an alternate analytical population that avoided some of these limitations, a Tdap cohort was constructed, consisting of members of the full cohort documented to have received Tdap during 2008–2011. For sensitivity analyses, missing brand information was imputed on the basis of available information under the missing-at-random assumption. Confounding occurs when a third, unmeasured variable is associated both with the risk factor of interest (eg, Tdap brand information) and the outcome (eg, pertussis) [2]. For example, the association between sex and lung cancer is confounded by the fact that men smoke more than women; smoking correlates with both sex (the putative risk factor) and lung cancer (the outcome). Because of the particular circumstances of Wisconsin with respect to both Tdap brand use and WIR participation and accuracy, the attempt to use the WIR to evaluate pertussis incidence by Tdap brand suffers from multiple confounders. Wisconsin is characterized by many small practices, along with a few very large institutions that predominate in a given subregional or cross-regional area; these providers typically use only 1 brand of Tdap. The likelihood of participating in the WIR and the likelihood of accurate data entry varied by institution and thus varied by geographic location. Relative market share of the 2 Tdap brands varied markedly during the study period and between private and public markets. There were issues for both private and public supplies of Tdap during the study period that led to unplanned changes in the Tdap brand used at various practices, increasing the likelihood of misreporting and miscategorization. A partial list of the confounding correlations includes geographic location and Tdap brand use, geographic location and accuracy and completeness of recording, practice and Tdap brand use, practice and likelihood or accuracy of WIR reporting, year and accuracy and completeness of WIR reporting, Tdap brand use and year, and likelihood of having left Wisconsin and year (and thus Tdap brand). The authors' analyses controlled for Wisconsin region, but these variations in practice behavior (eg, Tdap choice and WIR participation) did not respect regional boundaries, and many of these other confounders are beyond adequate control on the basis of available WIR data. Why does this matter? Consider that if a large institution used only a single brand of pertussis vaccine and that the large institution also was an early and faithful user of WIR (and we know that both of these suppositions are valid), then the WIR size (the denominator for rate calculations) is overrepresented with reports of use of that brand, thus lowering the apparent relative risk of pertussis for that brand. And this is only one of many such examples. Moreover, it is clear that brand misclassification might indeed be differential and that the missing-at-random assumption, used to impute the missing brand information, was not valid. Many of the considerations raised above do not apply to the primary study result, which describes the overall effectiveness of Tdap vaccine against pertussis. Regarding the brand-specific estimates, however, we strongly agree with the authors that their “VE estimates may be biased or confounded by uncontrolled client-level factors” (pp. 949–950 [1]).
Laura Conklin - One of the best experts on this subject based on the ideXlab platform.
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data on the implementation of vaxtrac electronic Immunization Registry in sierra leone
Data in Brief, 2020Co-Authors: Apophia Namageyofuna, Mohamed F Jalloh, Brigette Gleason, Aaron S Wallace, Michael Friedman, Tom Sesay, Dennis Ocansey, Leora R Feldstein, Laura ConklinAbstract:Abstract Following the piloting of VaxTrac, an electronic Immunization Registry (EIR), we conducted a rapid assessment in November-December 2017 to evaluate the use of the EIR in 10 health facilities in Western Area Urban district in Sierra Leone [1] . In this data-in-brief report, we provide additional descriptive data from the assessment of the VaxTrac EIR in Sierra Leone. The assessment comprised aggregate data on vaccine doses administered that were abstracted from VaxTrac and three paper-based sources (daily tally sheets, register of children under the age of 2 years, and a summary form of doses administered). Data were abstracted for the following six vaccine doses in the Immunization schedule in Sierra Leone: 1) Bacillus Calmette–Guerin vaccine, 2) first dose of pentavalent vaccine, 3) second dose of pentavalent vaccine, 4) third dose of pentavalent vaccine, 5) first dose of measles-containing vaccine, and 6) second dose of measles-containing vaccine. We descriptively analysed the abstracted data to examine the congruity between VaxTrac records and the three paper-based sources. Bar graphs were generated to visually depict the variations in number of administered vaccine doses by data source for each health facility. We provide the aggregated data for each vaccine dose abstracted by data source from each health facility as supplemental material (Excel file). The supplementary data reveal patterns in the congruity of vaccine doses captured that have implications for policy and programmatic decisions regarding the use of VaxTrac and other similar EIRs in low resource urban settings.
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assessment of vaxtrac electronic Immunization Registry in an urban district in sierra leone implications for data quality defaulter tracking and policy
Vaccine, 2020Co-Authors: Apophia Namageyofuna, Mohamed F Jalloh, Brigette Gleason, Aaron S Wallace, Michael Friedman, Tom Sesay, Dennis Ocansey, Leora R Feldstein, Laura ConklinAbstract:Abstract Background In 2016, the Sierra Leone Ministry of Health and Sanitation (MoHS) piloted VaxTrac, an electronic Immunization Registry (EIR), in an urban district to improve management of vaccination records and tracking of children who missed scheduled doses. We aimed to document lessons learned to inform decision-making on VaxTrac and similar EIRs’ future use. Methods Ten out of 50 urban health facilities that implemented VaxTrac were purposively selected for inclusion in a rapid mixed-method assessment from November to December 2017. For a one-month period, records of six scheduled vaccine doses among children Results Overall, VaxTrac captured Conclusion Although VaxTrac helped to shorten the time to manage, summarize, and report vaccination records, data sharing restrictions coupled with inconsistent and inefficient workflows were major implementation challenges. Readiness-to-introduce and sustainability should be carefully considered before implementing an EIR.
Jeffrey P Davis - One of the best experts on this subject based on the ideXlab platform.
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completeness and accuracy of the wisconsin Immunization Registry an evaluation coinciding with the beginning of meaningful use
Journal of Public Health Management and Practice, 2015Co-Authors: Ruth Koepke, Stephanie L Schauer, Matthew J Verdon, Daniel J Hopfensperger, Ashley B Petit, Roman Ayele, Jens C Eickhoff, James H Conway, Jeffrey P DavisAbstract:CONTEXT Vaccination coverage rates can be improved through the application of complete and accurate Immunization information systems (IISs). OBJECTIVE Evaluate the completeness and accuracy of Wisconsin's IIS, the Wisconsin Immunization Registry (WIR). DESIGN Cross-sectional evaluation, comparing vaccination medical records (MRs) from provider clinics with WIR records. PARTICIPANTS Medical records of patients born during 2009 were randomly selected from 251 Wisconsin clinics associated with the Vaccines for Children Program. MAIN OUTCOME MEASURES Completeness: percentage of patients with client records in the WIR, percentage of patients up-to-date (%UTD) with the 4:3:1:3:3:1:4 vaccination series, and percentage of patients' MR vaccinations matched by administration date (±10 days) and type to vaccinations documented in the WIR. Accuracy: percentages of matched vaccinations with the same administration date, same trade name (TN), and same lot number. RESULTS Of the 1863 selected patient MRs, 98% (n = 1833) had WIR client records and 97% of their 30 899 vaccinations were documented in the WIR. The %UTD was 49.3% using the MR only, 76.5% using the WIR only, and 75.2% as estimated by the National Immunization Survey. Among matched vaccinations, 99% had the same administration date, 96% had the same TN, and 95% had the same lot number. Compared with patients from clinics that entered data into the WIR using data exchange from electronic health records, patients from clinics that entered data using the Web-based user interface were less likely to have client records in the WIR (odds ratio: 0.3; 95% confidence interval: 0.1-0.9) and less likely to have accurate TNs (odds ratio: 0.3; 95% confidence interval: 0.1-0.5). CONCLUSIONS The WIR was complete and accurate among this sample of children born during 2009 and provided a vaccination coverage assessment similar to the National Immunization Survey. Our results provide support for the expectation that meaningful use and other initiatives that increase data exchange from electronic health records to IISs will improve IIS data quality.
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estimating the effectiveness of tetanus diphtheria acellular pertussis vaccine tdap for preventing pertussis evidence of rapidly waning immunity and difference in effectiveness by tdap brand
The Journal of Infectious Diseases, 2014Co-Authors: Ruth Koepke, Stephanie L Schauer, Daniel J Hopfensperger, Ashley B Petit, Roman Ayele, Jens C Eickhoff, James H Conway, Jeffrey P DavisAbstract:Background We estimated the vaccine effectiveness (VE) of tetanus-diphtheria-acellular pertussis vaccine (Tdap) for preventing pertussis among adolescents during a statewide outbreak of pertussis in Wisconsin during 2012. Methods We used the population-based Wisconsin Immunization Registry (WIR) to construct a cohort of Wisconsin residents born during 1998-2000 and collect Tdap vaccination histories. Reports of laboratory-confirmed pertussis with onset during 2012 were matched to WIR clients. Incidence rate ratios (IRRs) of pertussis and Tdap VE estimates [(1 - IRR)*100%], by year of Tdap vaccine receipt and brand (Boostrix/Adacel), were estimated using Poisson regression. Results Tdap VE decreased with increasing time since receipt, with VEs of 75.3% (95% confidence interval [CI], 55.2%-86.5%) for receipt during 2012, 68.2% (95% CI, 60.9%-74.1%) for receipt during 2011, 34.5% (95% CI, 19.9%-46.4%) for receipt during 2010, and 11.9% (95% CI, -11.1% to 30.1%) for receipt during 2009/2008; point estimates were higher among Boostrix recipients than among Adacel recipients. Among Tdap recipients, increasing time since receipt was associated with increased risk, and receipt of Boostrix (vs Adacel) was associated with decreased risk of pertussis (adjusted IRR, 0.62 [95% CI, .52-.74]). Conclusions Our results demonstrate waning immunity following vaccination with either Tdap brand. Boostrix was more effective than Adacel in preventing pertussis in our cohort, but these findings may not be generalizable to adolescent cohorts that received different diphtheria-tetanus-acellular pertussis vaccines (DTaP) during childhood and should be further examined in studies that include childhood DTaP history.
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the wisconsin Immunization Registry experience comparing real time and batched file submissions from health care providers
WMJ : official publication of the State Medical Society of Wisconsin, 2014Co-Authors: Stephanie L Schauer, Thomas R Maerz, Matthew J Verdon, Daniel J Hopfensperger, Jeffrey P DavisAbstract:CONTEXT The Wisconsin Immunization Registry is a confidential, web-based system used since 1999 as a centralized repository of Immunization information for Wisconsin residents. OBJECTIVE Provide evidence based on Registry experiences with electronic data exchange, comparing the benefits and drawbacks of using the Health Level 7 standard, including the option for real time data exchange vs the flat file method. DESIGN For data regarding vaccinations received by children aged 4 months through 6 years with Wisconsin addresses that were submitted to the Registry during 2010 and 2011, data timeliness (days from vaccine administration to date information was received) and completeness (percentage of records received that include core data elements for electronic storage) were compared by file submission method. RESULTS Data submitted using Health Level 7 were substantially more timely than data submitted using the flat file method. Additionally, data submitted using Health Level 7 were substantially more complete for each of the core elements compared to flat file submission. CONCLUSIONS Health care organizations that submit electronic data to Immunization information systems should be aware that the technical decision to use the Health Level 7 format, particularly if real-time data exchange is employed, can result in more timely and accurate data. This will assist clinicians in adhering to the Advisory Committee on Immunization Practices schedule and reducing over-Immunization.