On-label and off-label use of high-dose influenza vaccine in the United States, 2010–2012

Abstract

High-dose inactivated, influenza vaccine was licensed by the FDA in December 2009 for adults aged 65 y and older. The ACIP did not issue or state a preference for a specific vaccine in the elderly population. The extent of its on-label and off-label use is unknown. Using the MarketScan Commercial Claims and Encounters and the Medicare Supplemental database, we identified individuals who received the high-dose influenza vaccine or the standard, seasonal trivalent influenza vaccine between January 1, 2010 and December 31, 2012. For people aged ≥65 y, we used multivariable regression to assess the association between patient and provider level variables and high-dose influenza vaccine versus standard influenza vaccine. We characterized all off-label high-dose vaccine administered to people younger than 65 y of age, and investigated whether sicker patients were targeted for off-label use by examining the association between various comorbid conditions and receipt of the high-dose vaccine among adults aged 18–64. Among patients aged ≥65 y who received an influenza vaccine, 18.4% received the high-dose vaccine. Uptake was minimal in 2010, but 25% and 32% of influenza shots were the high-dose formulation in 2011 and 2012, respectively. Almost 27,000 seniors received a second high-dose vaccine with a median of 368 d (IQR: 350–387 days) between doses. Older age, family practice physicians, and having PPO insurance were positively associated with receiving high-dose vaccine. There were 36,624 off-label high-dose vaccines administered. Half of the patients receiving off-label doses were aged 50–64. Adults aged 18–64 y receiving high-dose vaccine were more likely to have chronic comorbidities than people receiving standard influenza vaccine; however, there was not one specific illness that seemed to be targeted by physicians. In the first 3 y since licensure, use of the high-dose vaccine among seniors has been limited. The safety of this vaccine should be monitored closely among 2 groups of people - seniors receiving repeat doses and people <65.

Keywords:

• adult vaccination
• high-dose influenza vaccine
• influenza vaccine
• influenza prevention

Abbreviations:

• ACIP, Advisory Committee on Immunization Practices
• CPT, Current Procedural Terminology
• ICD-9-CM, International Classification of Diseases
• Ninth Revision, Clinical Modification, IQR
• Interquartile range
• HMO, Health Maintenance Organization
• PPO, Preferred provider organization

Disclosure of Potential Conflicts of Interest

MAB receives investigator-initiated research funding from the National Institutes of Health (R01 AG042845, R21 HD080214, R01 AG023178) and through contracts with the Agency for Healthcare Research and Quality's DEcIDE program and the Patient Centered Outcomes Research Institute. He has served as a scientific advisor for Amgen, Merck, GSK (honoraria/payment received by the institution). He received consulting fees from RxAnte and World Health Information Consultants. LM has no conflicts of interests.

Authors’ Contributions

LM designed the study, analyzed and interpreted the data, drafted and revised the manuscript. MAB acquired and interpreted the data and revised the manuscript. The final manuscript has been approved by both authors.

Acknowledgment

We thank Virginia Pate for providing assistance with statistical programming and data management.