The influence of free quadrivalent human papillomavirus vaccine (HPV4) on the timely completion of the three dose series.

OBJECTIVE: Economic incentives can positively influence social determinants to improve the health care of the uninsured and underserved populations. The aim of this study was to determine if free HPV4 vaccine would lead to on-time series completion in our safety net health care system in the US Midwest. METHODS: A nested retrospective cohort study of females receiving HPV4 vaccine between 2006 and 2009 was conducted. Patient characteristics and payor source for each of the three HPV4 doses were abstracted from electronic records. Logistic regression was used to predict on-time completion rates. RESULTS: The proportion of adolescent and adult females completing three on-time HPV4 doses was equal (21% (28/136) vs. 18% (66/358), respectively) from among the 494 females receiving 927 HPV4 doses in this study. No adolescent receiving free HPV4 vaccine completed three doses. Grant sponsorship of at least one HPV4 dose among adults did not predict three dose on-time completion (OR=1.56, 95%CI: 0.80, 3.06). Neither was adult grant sponsorship of HPV4 significant when analyzing exclusive payor sources vs. a combination of payor sources (OR=0.72, 95%CI: 0.10, 5.17). CONCLUSIONS: Free HPV4 vaccine does not influence the on-time completion rates among adults.

Urban and rural safety net health care system clinics: no disparity in HPV4 vaccine completion rates.

OBJECTIVE: Safety net health care centers in the US serve vulnerable and underinsured females. The primary aim of this work was to determine if HPV4 dosing compliance differs between females who receive doses at rural vs. urban core safety net health care locations. METHODS: Females exclusively receiving health care in the Truman Medical Center (TMC) safety net system at the urban core and rural locations were identified by their HPV4 vaccine records. Dates and number of HPV4 doses as well as age, gravidity, parity and race/ethnicity were recorded from the electronic medical record (EMR). Appropriate HPV4 dosing intervals were referenced from the literature. RESULTS: 1259 females, 10-26 years of age, received HPV4 vaccination at either the rural (23%) or urban core location (77%). At the rural location, 23% received three doses on time, equal to the 24% at the urban core. Females seen in the urban core were more likely to receive on-time doublet dosing than on-time triplet dosing (82% vs. 67%, p<0.001). Mistimed doses occurred equally often among females receiving only two doses, as well as those receiving three doses. CONCLUSIONS: Compliance with on-time HPV4 triplet dose completion was low at rural and urban core safety net health clinics, but did not differ by location.

In a safety net population HPV4 vaccine adherence worsens as BMI increases.

OBJECTIVES: Obesity adversely inhibits antibody response to vaccination. Three doses of HPV4 may or may not provide adequate long term protection against HPV 16/18 in obese females. The aim of this study was to determine whether adherence to HPV4 vaccination in a safety net population was reduced with increasing body mass index (BMI). METHODS: We designed a historical prospective study evaluating the number and dates of HPV4 dosing that occurred from July 1, 2006 through October 1, 2009 by the demographic characteristics of the 10-26 year old recipient females. The defined dosing intervals were adapted from the literature and obesity categories were defined by the WHO. RESULTS: 1240 females with BMI measurements received at least one dose of HPV4; 38% were obese (class I, II and III) and 25% were overweight. Females with normal BMI received on-time triplet dosing significantly more often than did the obese class II and III females (30% vs. 18%, p<0.001). Obese class II/III females have a significant 45% less chance of completing the on-time triplet HPV4 series than normal women (OR = 0.55, 95% CI: 0.37, 0.83). Pregnancy history has a significant influence on BMI and HPV4 dosing compliance in this safety net population where 71% had been gravid. Hispanic females were less likely to complete HPV4 dosing regardless of BMI (aOR = 0.39, 95% CI: 0.16, 0.95). CONCLUSIONS: Obesity, as well as gravidity and Hispanic race, are risk factors for lack of HPV4 vaccine adherence among young females in a safety net population.