SAN DIEGO (FRONTLINE MEDICAL NEWS)Missed vaccination opportunities are common among adolescents with chronic medical conditions, especially for the first human papillomavirus (HPV) vaccine dose and for those who require the pneumococcal polysaccharide vaccination, an urban-based retrospective analysis showed.

“There are surprisingly little data describing routine vaccination coverage and missed opportunities for vaccination among the growing population of adolescents with chronic medical conditions,” Dr. Annika M. Hofstetter said in an interview in advance of the annual meeting of the Pediatric Academic Societies. “This study was unique in that it examined all recommended vaccines for adolescents with chronic medical conditions. A particular strength was the use of a large hospital immunization information system linked with other databases containing demographic, visit, and clinical information relevant to vaccination.”

Dr. Hofstetter, who conducted the study with colleagues while a faculty member in the department of pediatrics at Columbia University, New York, evaluated the records of 3,989 patients aged 11-17 years who received care at one of four clinics affiliated with the university between August 2011 and June 2013. The researchers used ICD-9 codes to identify adolescents with chronic medical conditions and chi square analysis to compare vaccination coverage and missed opportunities for vaccination among those with and without chronic medical conditions. They also used multivariable logistic regression to evaluate the impact of demographic and visit characteristics on vaccination outcomes.

Dr. Hofstetter, now a pediatrician at Seattle Children’s Hospital and the University of Washington, reported that 97% of the adolescents were nonwhite, 60% spoke Spanish, and 82% were publicly insured.

Fewer adolescents with chronic medical conditions had initiated HPV vaccination, compared with their healthy counterparts (81% vs. 85%, respectively), yet a higher percentage had received influenza vaccine during the 2012-2013 season (74% vs. 64%), “although still suboptimal,” the researchers wrote in their abstract. Other routine vaccination coverage was similar between groups (about 97% for tetanus/diphtheria/pertussis; 94% for meningococcal vaccine, and 58% for three or more doses of HPV vaccine).

Missed opportunities for routine vaccination were higher among adolescents with chronic medical conditions, compared with their healthy counterparts (47% vs. 41%), as were missed opportunities for initiating HPV vaccination at visits where other needed vaccines were administered (63% vs. 52%).

When the researchers limited the analysis to adolescents with chronic medical conditions, they found that subspecialty care was inversely associated with HPV vaccination and had no impact on influenza vaccination. Among those who required a pneumococcal polysaccharide vaccination as per Advisory Committee of Immunization Practices recommendations, only 36% had received a dose in their lifetime. Most (91%) had one or more missed opportunities to receive the pneumococcal polysaccharide vaccine.

“Missed opportunities for vaccination of adolescents with chronic medical conditions were common,” Dr. Hofstetter concluded. “Strategies that act to reduce missed opportunities and enhance uptake for these at-risk adolescents are needed. Specifically, it will be important to focus on: 1) improving rates of HPV vaccination initiation among boys with chronic medical conditions; 2) optimizing influenza vaccination of adolescents with chronic medical conditions since, although they had higher rates than their healthy counterparts, they are at increased risk of influenza-associated complications; and 3) increasing the markedly low pneumococcal polysaccharide vaccination coverage of eligible patients.”

She acknowledged certain limitations of the study, including the fact that it focused solely on low-income minority patients attending four urban pediatric clinics with high baseline vaccination coverage. “Thus, the findings may be less generalizable to other populations and settings across the country,” she said.

This investigator-initiated study was supported in part by the Pfizer Medical Education Group. Dr. Hofstetter disclosed that she previously received research support for another investigator-initiated study from the Merck Investigator Studies Program.

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