Peter M Wahl

Publications (2)6.29 Total impact

• Source

  Available from: Donnie Funch

  Article: Algorithms for identification of Guillain-Barré Syndrome among adolescents in claims databases.

  Donnie Funch, Crystal Holick, Priscilla Velentgas, Robin Clifford, Peter M Wahl, Cheryl McMahill-Walraven, Patricia Gladowski, Richard Platt, Anthony Amato, K Arnold Chan
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  ABSTRACT: BACKGROUND: Health insurance claims databases can provide data for studies of vaccine-related Guillain-Barre' Syndrome (GBS), but not all patients with a diagnostic ICD-9-CM code for GBS have the disease. The objective of this study was to evaluate the positive predictive values (PPVs) of claims-based algorithms for identifying GBS cases in 4 claims database environments. METHODS: Potential cases were adolescents ages 11-21 with at least one claim for GBS (ICD-9-CM code 357.0). Medical record reviews by a panel of 3 neurologists were conducted for case confirmation. Claims data considered for inclusion in the case-ascertainment algorithm included coding position, physician specialty, visit type, diagnostic tests. PPVs were used to assess the contribution of study factors in predicting case status. RESULTS: Among 361 individuals with a GBS diagnosis code, 106 were confirmed overall (PPV=0.29), varying from 0.24 to 0.56 across the 4 sites. Requiring the GBS code to be associated with a neurologist visit (PPV=0.53) or to be in a primary position on an inpatient claim (0.56) improved the performance. A composite algorithm including a primary inpatient GBS code and a neurologist visit associated with any GBS code gave the highest PPV (0.70). Incorporating claims for diagnostic testing had little impact on the PPV. Findings were generally similar across study sites. CONCLUSIONS: Algorithms were able to identify GBS cases better than the single occurrence of the diagnostic code for GBS, and these algorithms may perform similarly in different claims environments.
  Vaccine 03/2013; · 3.77 Impact Factor
• Article: Risk of Guillain-Barré syndrome after meningococcal conjugate vaccination.

  Priscilla Velentgas, Anthony A Amato, Rhonda L Bohn, K Arnold Chan, Thomas Cochrane, Donnie P Funch, Inna Dashevsky, April L Duddy, Patricia Gladowski, Steven A Greenberg, Judith M Kramer, Cheryl McMahill-Walraven, Cynthia Nakasato, Claire M Spettell, Beth L Syat, Peter M Wahl, Alexander M Walker, Fang Zhang, Jeffrey S Brown, Richard Platt
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  ABSTRACT: PURPOSE: A new meningococcal conjugate vaccine (MCV4) was introduced in 2005. Shortly after, case reports of Guillain-Barré syndrome (GBS), a serious demyelinating disease, began to be reported to the Vaccine Adverse Event Reporting System. In 2006, the Centers for Disease Control and Prevention and the Food and Drug Administration requested the evaluation of GBS risk after MCV4 vaccination. We conducted a study to assess the risk of GBS after MCV4 vaccination using health plan administrative and claims data together with the review of primary medical records of potential cases. METHODS: Retrospective cohort study among 12.6 million 11- to 21-year-old members of five US health plans with a total membership of 50 million. Automated enrollment and medical claims data from March 2005 through August 2008 were used to identify the population, the vaccinations administered, and the medical services associated with possible GBS. Medical records were reviewed and adjudicated by a neurologist panel to confirm cases of GBS. The study used distributed data analysis methods that minimized sharing of protected health information. RESULTS: We confirmed 99 GBS cases during 18,322,800 person-years (5.4/1,000,000 person-years). More than 1.4 million MCV4 vaccinations were observed. No confirmed cases of GBS occurred within 6 weeks after vaccination. The upper 95% CI for the attributable risk of GBS associated with MCV4 is estimated as 1.5 cases per 1,000,000 doses. CONCLUSIONS: Among members of five US health plans, MCV4 vaccination was not associated with increased GBS risk. Copyright © 2012 John Wiley & Sons, Ltd.
  Pharmacoepidemiology and Drug Safety 07/2012; · 2.53 Impact Factor