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.

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.

Quantifying clinical HPV4 dose inefficiencies in a safety net population.

PURPOSE: HPV4 is the most expensive vaccine requiring three appropriately timed doses to provide maximal efficacy against two oncogenic HPV types. The primary purpose of this study is to quantify the use of HPV4 vaccine in a safety net health care system in terms of its inefficiencies. METHODS: A retrospective study of HPV4 dosing from 2006-2009, among females 10-26 years old who sought care in a safety net health care system was conducted to determine dose usage patterns among those at highest risk for cervical cancer. Dose descriptors abstracted from the electronic medical record (EMR) included timing and number in series as well as characteristics of the person to whom and visit at which the dose was given. Dose inefficiencies were separated into "less than three doses" and "mistimed doses" for analysis. RESULTS: The majority (66%) of HPV4 doses administered were insufficient to induce the maximal immune response necessary for HPV infection prevention. Among on-time doses, 58% were singleton or doublet doses. Mistimed doses accounted for 19% of all doses administered with late intervals being more common than early intervals among those receiving more than one dose (9% vs. 4%, p<0.001). Third doses were mistimed twice as often as second doses (10% vs. 5%, p<0.001). Black women were more likely to have a mistimed second dose and Hispanic women more likely to have a mistimed third dose compared to white women (OR = 1.70 (95% CI: 1.11, 2.61 and 2.44 (1.19, 5.00), respectively). The HPV4-only visit type at which HPV4 was initiated was the most significant predictor of on-time doublet completion. CONCLUSIONS: In a safety net health care system the large inefficiencies associated with HPV4 vaccination must be addressed in order to maximize our patient's cervical cancer prevention.