Abstract
This cross-sectional study examines the rate of HPV vaccination and the number eligible for this vaccination among younger veterans and civilians.
In the US, over 45 000 cases of human papillomavirus (HPV)–associated malignant neoplasms are diagnosed annually.1 The Advisory Committee on Immunization Practices recommends HPV vaccination until age 26 years to prevent HPV-associated malignant neoplasms in males and females. Active-duty military service members and veterans are twice as likely as the general population to develop oncogenic HPV infections, resulting in a higher risk of HPV-associated cancers and mortality,2,3,4 and HPV-associated oropharyngeal cancer, which occurs predominantly in males, is rising more rapidly among veterans than civilians.3 There are no universal HPV vaccination requirements or campaigns targeted at service members or veterans.5 In this study, we provide, to our knowledge, the first national estimate of HPV vaccination prevalence among eligible veterans.
Methods
Using data from the Veterans Health Administration (VHA) Corporate Data Warehouse (CDW), we conducted a national cross-sectional study of veterans aged 18 to 26 years with at least 1 VHA primary care visit between January 1, 2018, and December 31, 2020. The St Louis VA Medical Center Review Board approved this study and deemed it exempt from the informed consent requirement because it involved only retrospective review. We followed the STROBE reporting guideline.
We constructed an age-matched representative sample of the US population using the 2017 to 2020 National Health and Nutrition Examination Survey to compare HPV vaccination prevalence between civilians and veterans. Logistic regression model was used to determine the association between sociodemographic and geographic factors and history of HPV vaccination. In the CDW, race and ethnicity are self-reported, and sex refers to birth sex, which can be changed by request to reflect gender identity. The SAS Enterprise Guide 9.2 (SAS Institute) and R 4.2.0 (R Core Team) were used to perform statistical analyses.
Results
Vaccination prevalence and multivariable regression analysis results are provided in the Table. A total of 128 279 veterans (mean [SD] age, 24.4 [1.6] years; 79.2% males and 20.8% females) were included in the analysis. Among veterans aged 18 to 26 years, 30.2% of females and 18.7% of males received HPV vaccination vs 62.4% of females and 37.0% of males in the general population. Vaccination odds decreased with 1-unit increase in age (adjusted odds ratio [aOR], 0.95; 95% CI, 0.94-0.96) and increase in percentage of households living at 125% of poverty level or under (aOR, 0.83; 95% CI, 0.72-0.96).
Table. HPV Vaccination Prevalence and aORs of HPV Vaccination of Veterans Aged 18 to 26 Years Receiving Primary Care Within the VHAa.
| Characteristic | Males | Females | All veterans, aOR (95% CI) | ||
|---|---|---|---|---|---|
| Total No. | % Vaccinated (95% CI) | Total No. | % Vaccinated (95% CI) | ||
| Sex | 101 646 | 18.7 (18.5-18.9) | 26 633 | 30.2 (29.6-30.8) | 0.52 (0.50-0.53) [Reference: female sex] |
| Race and ethnicityb | |||||
| Asian American and Pacific Islander | 3172 | 28.9 (28.6-29.2) | 851 | 37.8 (34.5-41.1) | 1.76 (1.63-1.60) |
| Black | 14 644 | 18.2 (18-18.4) | 6443 | 27.8 (26.7-28.9) | 1.01 (0.97-1.05) |
| Hispanic | 16 612 | 21.4 (21.1-21.6) | 4406 | 32.5 (31.1-33.8) | 1.09 (0.91-1.30) |
| Native American | 566 | 20.1 (19.5-20.3) | 198 | 25.2 (19.1-31.2) | 1.28 (1.23-1.33) |
| White | 53 798 | 17.5 (17.2-17.7) | 10 728 | 31.5 (30.6-32.4) | 1 [Reference] |
| Otherc | 6695 | 19.8 (19.5-20) | 2278 | 28.7 (26.8-30.6) | 1.12 (1.06-1.19) |
| Missing data | 6159 | NA | 1729 | NA | NA |
| Branch of service | |||||
| Army | 46 279 | 17.8 (17.6-18) | 12 261 | 31.1 (30.2-31.9) | 1 [Reference] |
| Air Force | 8944 | 21.9 (21.6-22.1) | 3187 | 33.2 (31.5-34.8) | 1.25 (1.19-1.31) |
| Coast Guard | 483 | 20.7 (20.4-20.9) | 174 | 28.1 (21.4-34.8) | 1.08 (0.89-1.31) |
| Marine Corps | 32 665 | 18.9 (18.7-19.1) | 4617 | 30 (28.7-31.3) | 1.02 (0.99-1.06) |
| Navy | 11 996 | 19.3 (19.1-19.5) | 5724 | 27.6 (26.4-28.8) | 0.97 (0.93-1.02) |
| Otherd | 9 | 11.1 (10.9-11.3) | 4 | NA | NA |
| Missing data | 1270 | NA | 666 | NA | NA |
| Rural-urban status | |||||
| Urban | 87 188 | 18.9 (18.7-19.1) | 23 402 | 30.2 (29.6-30.8) | 1 [Reference] |
| Large rural | 8315 | 16.9 (16.7-17.1) | 1845 | 30.1 (28-32.2) | 0.89 (0.84-0.94) |
| Small rural | 3184 | 17.3 (17.1-17.5) | 689 | 29.2 (25.8-32.6) | 0.91 (0.83-0.99) |
| Isolated | 1915 | 18.5 (18.3-18.7) | 363 | 33.3 (28.4-38.1) | 0.99 (0.89-1.10) |
| Missing data | 1044 | NA | 334 | NA | NA |
| Regione | |||||
| Pacific | 22 238 | 21.7 (21.4-21.9) | 5533 | 29.7 (28.5-30.9) | 1 [Reference] |
| Continental | 19 692 | 13.5 (13.2-13.7) | 5920 | 23.7 (22.6-24.8) | 0.64 (0.61-0.67) |
| Midwest | 18 508 | 22.03 (21.8-22.3) | 3590 | 38.4 (36.8-39.9) | 1.24 (1.19-1.30) |
| North Atlantic | 21 613 | 15.7 (15.4-15.9) | 5655 | 26.7 (25.5-27.8) | 0.77 (0.74-0.80) |
| Southeast | 19 595 | 20.6 (20.3-20.8) | 5935 | 35.4 (34.2-36.6) | 1.12 (1.08-1.17) |
Abbreviations: aOR, adjusted odds ratio; HPV, human papillomavirus; NA, not applicable; VHA, Veterans Health Administration.
Multivariable model was adjusted for variables shown in the table and the continuous variables of age and percentage living in households with income 125% of the poverty level or under.
Race and ethnicity were self-reported.
Other race and ethnicity included unknown or no response.
Other service branch included US Public Health Service Commissioned Corps and National Oceanic and Atmospheric Administration.
Regions included the following VA districts. Pacific: Washington, Oregon, Nevada, California, Arizona, New Mexico, Alaska, and Hawaii. Continental: Idaho, Montana, Utah, Texas, Oklahoma, Colorado, Mississippi, Louisiana, Arkansas, and Wyoming. Midwest: North Dakota, South Dakota, Nebraska, Kansas, Minnesota, Iowa, Missouri, Wisconsin, Michigan, Indiana, Illinois, and Ohio. North Atlantic: Maine, Vermont, New Hampshire, Massachusetts, Connecticut, New York, Rhode Island, Pennsylvania, New Jersey, West Virginia, Virginia, North Carolina, Delaware, Washington, DC, and Maryland. Southeast: Alabama, Georgia, South Carolina, Florida, Kentucky, and Tennessee.
The Figure shows vaccination prevalence and number of veterans under age 30 years. Wyoming (6.1%; 95% CI, 3.1%-9.1%), Oklahoma (10.9%; 95% CI, 9.39%-12.41%), and Texas (11.9%; 95% CI, 11.35-12.45) had the lowest vaccination rates. Hawaii (53.9%; 95% CI, 50.1-57.6%) and North Dakota (49.2%; 95% CI, 43.8%-54.6%) had the highest rates. Texas and Virginia were among states with the lowest rates and the largest populations of veterans younger than 30 years.
Figure. Human Papillomavirus Vaccination Prevalence Among US Veterans Aged 18 to 26 Years and Number of Veterans Younger Than 30 Years by State .
aData are from the Veterans Health Administration Corporate Data Warehouse (https://www.data.va.gov/dataset/Corporate-Data-Warehouse-CDW-/ftpi-epf7).
bData are from the US Department of Veterans Affairs Veteran Population Projection Model (https://www.va.gov/vetdata/veteran_population.asp).
Discussion
Prevalence of HPV vaccination among eligible veterans was one-half that among civilians. High HPV-infection prevalence, rising HPV-associated oropharyngeal cancer incidence,3 and low vaccination rates may be associated with increases in HPV-associated cancer morbidity and mortality among veterans.
Findings suggest catch-up HPV vaccination campaigns are needed for younger service members and veterans. We identified regions with low veteran vaccination prevalence and large eligible veteran populations wherein these interventions may be most impactful. Only 37.8% female and 3.9% male active-duty service members have reported initiating the HPV vaccine series.6 The VHA has spent approximately $136 million to treat HPV-associated cancers that are preventable with vaccination.4 Without effective HPV vaccination strategies, the VHA will bear the financial burden of HPV-associated malignant neoplasms for decades to come.
Study limitations were inclusion of only veterans interacting with the VHA and imperfect transfer of historical medical records to new settings such as the VHA that could result in underestimation of vaccination prevalence. The findings provide the VHA and Department of Defense an opportunity to design and implement HPV prevention campaigns, which could be extrapolated to civilians, among whom vaccination rates remain suboptimal. In doing so, the VHA can prioritize cancer prevention and impart lessons to other health care delivery systems.
Data Sharing Statement
References
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Associated Data
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Supplementary Materials
Data Sharing Statement
