<p>The objective of this study was to describe how a sample of pediatricians were impacted by and responded to the Disneyland measles outbreak in the United States. We conducted three repeated cross-sectional, online surveys in 2014 (before the outbreak), 2015, and 2016 (after the outbreak) among members of three state chapters of the American Academy of Pediatrics. We assessed pediatricians' level of willingness and length of time comfortable delaying the measles-mumps-rubella (MMR) vaccine before and after the outbreak. Frequency of alternative immunization schedule requests and creation of office immunization policies due to the outbreak were measured. The sample included 304 pediatricians in 2014, 270 in 2015, and 221 in 2016. We found no significant changes in willingness or comfort delaying the MMR vaccine before and after the outbreak. In 2015, 38% of pediatricians reported fewer requests for alternative immunization schedules and 20% created stricter office immunization policies. A subsample of pediatricians reported administering the MMR vaccine earlier in the recommended time frame and taking extra precautions in waiting rooms due to the outbreak. Our results suggest that this measles outbreak did not lead to significant changes in attitudes or practices among this sample, but did modestly affect office immunization policies and practices.</p>

<p>We conducted a cross-sectional online survey among 4 chapters of the American Academy of Pediatrics from July through October 2014 to describe characteristics of pediatricians and practices associated with practice-level responses to alternative immunization schedule requests. Among 374 pediatricians, 58% reported frequent alternative immunization schedule requests and 24% reported feeling comfortable using them. Pediatricians who work in practices that accommodate alternative immunization schedule requests have increased odds of having a high frequency of alternative immunization schedule requests, and beliefs that relationships with families would be negatively affected if they refused requests. Practices that discontinue care to families who request alternative immunization schedules have increased odds of being a private group practice and having a formal office vaccine policy. Pediatricians are frequently asked to use alternative immunization schedules and many are not comfortable using them. Practice-level responses to alternative immunization schedules are associated with characteristics of pediatricians and practices.</p>

<p><strong>BACKGROUND: </strong>A varicella diagnosis or verification of disease history by any healthcare provider is currently accepted for determining evidence of immunity by the Advisory Committee on Immunization Practices (ACIP).</p>

<p><strong>OBJECTIVE: </strong>To examine the accuracy of medical record (MR) documented varicella history as a measure of varicella-zoster virus (VZV) immunity among unvaccinated individuals born after 1980. We also assessed methods to practically implement ACIP guidelines to verify varicella history using medical records.</p>

<p><strong>STUDY DESIGN: </strong>As part of a larger cross-sectional study conducted at three Philadelphia clinics from 2004-2006, we recruited 536 unvaccinated patients aged 5-19 y (birth years: 1985-2001). Varicella history was obtained from three sources: parent/patient interview, any MR documentation (sick and well visits) and MR documentation of a sick visit for varicella. All participants were tested for VZV IgG. For each source and three age groups (5-9, 10-14, 15-19 y old), positive predictive value (PPV) was calculated. Specificity of varicella history was compared between different sources using McNemar's Chi-square.</p>

<p><strong>RESULTS: </strong>Among participants aged 5-9, 10-14 and 15-19 y the PPV for any MR documentation and sick visit diagnosis were 96% and 100%, 92% and 97%, and 99% and 100%, respectively. The specificity for sick visit documentation was higher than any MR documentation and patient/parent recall among all age groups; however, these differences were only statistically significant when comparing sick visit documentation to parent/patient recall for 10-14 y olds.</p>

<p><strong>CONCLUSION: </strong>Sick visit documentation of varicella in the MR is an accurate predictor of varicella seropositivity and useful for confirming disease history among unvaccinated persons (birth years: 1985-2001). This method is a practical way to verify varicella history using the ACIP guidelines.</p>