Vaccination rates among United States (US) adults are suboptimal, resulting in morbidity, mortality, and financial burden attributable to potentially vaccine-preventable diseases (VPDs). Unadjusted annual incidence proportions of VPDs were estimated for Medicaid and commercially insured adults aged 19-64 years using 2006-2010 claims, along with age/gender-adjusted incidence proportions for 2010. In 2010, 1.6 million Medicaid adults (mean age 34 ± 12 years; 73.4% female) and 33 million commercially insured (mean age 42 ± 13 years; 52.2% female) were included. Age/gender-adjusted incidence proportions (per 100 000) in 2010 among Medicaid vs commercially insured adults for meningococcal disease were 26.2 (95% CI 22.9-29.8) vs 2.0 (1.9-2.2) (P < 0.001); hepatitis B 88.9 (82.6-95.6) vs 17.5 (17.0-17.9) (P < 0.001); pneumococcal disease 98.2 (91.7-105.1) vs 21.1 (20.7-21.6) (P < 0.001); hepatitis A 19.8 (16.9-23.1) vs 4.5 (4.3-4.7) (P < 0.001); mumps 2.1 (1.3-3.3) vs 1.4 (1.3-1.6) (P = 0.14); measles 0.3 (0.1-1.0) vs 0.3 (0.2-0.3) (P = 0.38); herpes zoster (60- to 64-year-olds only) 459 (408-515) vs 473 (466-481) (P = 0.35); varicella (19- to 39-year-olds only) 6.5 (4.8-8.5) vs 8.0 (7.5-8.5) (P = 0.12); influenza 586 (573-598) vs 633 (631-636) (P < 0.001); and pertussis 1.8 (1.1-2.8) vs 3.2 (3.0-3.4) (P < 0.001). Research is needed to fully understand the causes of the disparity of the coded incidence of some VPDs in adult Medicaid population than commercially insured adults in the US.
Keywords: Medicaid; commercially insured; health disparity; immunization adults; vaccine-preventable diseases.