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closeAssessing Healthcare Utilization After Vaccination: The Benefits of an Integrated Health Information System
Posted by Karina_Top on 19 Jan 2012 at 19:53 GMT
Kumanan Wilson and colleagues [1] applied the self-controlled case series (SCCS) design to a large population-based cohort to determine the excess risk of a healthcare visit (specifically Emergency Department (ED) visits and hospitalizations) after measles-mumps-rubella (MMR) vaccination. A significantly increased risk of a healthcare visit (1 per 168 vaccinees) occurred 4 to 12 days after the first dose of MMR vaccine, with a smaller increase in risk observed after the second dose. These findings are very interesting and timely as healthcare providers and the public become increasingly concerned about vaccine safety [2]. However, the databases available for this study did not capture outpatient physician visits and included only limited information about the healthcare visit (e.g., primary diagnosis). Furthermore, risk factors for adverse events could not be determined. A fully integrated electronic health information system that contains information on all physician visits, public health nurse visits, diagnoses and vaccinations, similar to the Danish system [3], would be needed to fully determine the impact of vaccinations on healthcare utilization and to identify risk factors for adverse events leading to healthcare visits. Data collected through an integrated health information system could be used to determine the degree of symptom severity that leads to a healthcare visit and the impact of an adverse event on the timely administration of subsequent vaccines.
Karina A. Top, MD, Noni E. MacDonald, MD, Michael Graven, MD
Department of Pediatrics, Dalhousie University
Halifax, NS, Canada
1. Wilson K, Hawken S, Kwong JC, Deeks S, Crowcroft NS, et al. (2011) Adverse Events following 12 and 18 Month Vaccinations: a Population-Based, Self-Controlled Case Series Analysis. PLoS One 6: e27897.
2. Callreus T (2010) Perceptions of vaccine safety in a global context. Acta Paediatr 99: 166-171.
3. Hviid A (2006) Postlicensure epidemiology of childhood vaccination: the Danish experience. Expert Rev Vaccines 5: 641-649.
RE: Assessing Healthcare Utilization After Vaccination: The Benefits of an Integrated Health Information System
Kumanan replied to Karina_Top on 26 Jan 2012 at 16:20 GMT
We would like to thank Dr. Top and colleagues for their interest in our manuscript(1). We agree that better integration of datasets would be invaluable for vaccine surveillance as well as achieving other health objectives. However, we believe there is valuable information pertaining to vaccine surveillance can be derived from existing linked databases in Canada.
For example, the linked databases available to us do capture outpatient visits. We chose not to include these in our analyses because outpatient visits would be less specific for a serious adverse event related to vaccination and it would be more difficult to discern a signal from the background “noise”. However, an analysis of outpatient visit as separate endpoints did demonstrate a pattern similar to emergency room visits and admission.
Second, the question of reason for presentation is also available through the hospital and emergency room databases. We had provided some information on this in the manuscript and have more detailed information available. Ideally the diagnostic codes would be validated but this is a limitation of any database.
Third, we do have the ability to examine for some predictors of adverse events. This was beyond the scope of this article. In previous articles we have demonstrated how birth weight and gestational age influences the risk of an infant incurring an emergency room visit or hospital admission following the 2 month vaccination(2, 3). We intend to conduct similar analyses to determine if we can identify what factors predispose to an adverse event following the 12 month vaccination.
Fourth, the emergency room database provides information on acuity score which does provide some information as to level of illness of the child. In our analysis we observed that the acuity score was similar between the risk and control periods.
While more linked quality data is always preferable, we believe there is a considerable amount that can be done with existing data that can be highly informative to public health officials in the critical area of vaccine surveillance.
We again would like to thank the authors for their query and interest in our manuscript.
Sincerely,
Kumanan Wilson Steven Hawken
ICES@uOttawa, Ottawa Hospital Research Institute, University of Ottawa
1. Wilson K, Hawken S, Kwong JC, et al. Adverse Events following 12 and 18 Month Vaccinations: a Population-Based, Self-Controlled Case Series Analysis. PLoS One;6(12):e27897.
2. Wilson K, Hawken S, Kwong JC, et al. Impact of birth weight at term on rates of emergency room visits and hospital admissions following vaccination at 2 months of age. Vaccine;29(46):8267-74.
3. Wilson K, Hawken S. Incidence of adverse events in premature children following 2 month vaccination. Human vaccines and immunotherapeutics (in press). https://www.landesbioscie...