BACKGROUND: Children with sickle cell disease (SCD) have an increased risk for gallstones due to chronic hyperbilirubinemia from hemolysis. Although gallstones are a known complication, there is variability in estimates of disease burden and uncertainty in the association between sex and gall bladder disease (GBD).

METHODS: This was a retrospective cohort study of children with SCD using administrative claims data (January 1, 2014-December 31, 2018). Population-averaged multivariable panel-data logistic regression models were used to evaluate the association between GBD clinical encounters (outcome) and two exposures (age and sex). Annual GBD risk was calculated using predictive margins, adjusting for disease severity, transfusion frequency, and hydroxyurea exposure.

RESULTS: A total of 13,745 individuals (of 21,487 possible) met inclusion criteria. The population was evenly split across sex (49.5% female) with predominantly Medicaid insurance (69%). A total of 946 individuals (6.9%) had GBD, 432 (3.1%) had a gallstone complication, and 487 (3.5%) underwent cholecystectomy. The annual risk of GBD rose nonlinearly from 1 to 5% between ages 1 and 19 years with no difference between males and females. Cholecystectomy occurred primarily in individuals with GBD (87%), and neither age nor sex was associated with cholecystectomy in this population. High disease severity (compared with low) more than doubled the annual risk of GBD at all ages.

CONCLUSIONS: GBD is associated with age but not sex in children with SCD. Neither age nor sex is associated with risk of cholecystectomy. High disease severity increases the rate of GBD at all ages.

<p><strong>OBJECTIVE: </strong>Human papillomavirus (HPV) vaccine has been recommended for males for prevention of genital warts and precancerous anal lesions since 2009. Our objective was to characterize race and insurance-based disparities in HPV vaccine completion among males who initiated the HPV vaccine series.</p>

<p><strong>METHODS: </strong>Retrospective cohort study of adolescent males in a primary care network who initiated the HPV vaccine series 10/09-12/13. We measured vaccine series completion as the primary outcome. We evaluated associations between outcomes and race and insurance status, controlling for potential confounders and effect modification with multivariable logistic regression. Analyses were stratified by vaccine recommendation era (permissive vs. routine).</p>

<p><strong>RESULTS: </strong>42% of males in the cohort (16,691) completed the vaccine series. In the permissive vaccine era (2009 - 2011), non-black patients (53%) were more likely to complete than Black patients (32%), and non-Medicaid were more likely to complete than Medicaid patients (33%). These differences persisted in the routine recommendation era (2012 - 2013). In both the permissive and routine eras Medicaid insurance was associated with a larger reduction in the predicted probability of vaccine series completion for non-black patients. Adherence to the recommended vaccination schedule was low with a median time to completion of 8.9 months. Using the updated completion schedule (2016), completion rates were higher (54.1%) with continued differences based on race (60% vs. 45.7% for non-black vs. black patients) and insurance (57.4% vs. 46.4% completion for non-Medicaid vs. Medicaid patients).</p>

<p><strong>CONCLUSIONS: </strong>There are significant disparities in HPV vaccine series completion rates among males based on race and insurance, unchanged based on era of initiation or visit frequency.</p>

<p><strong>PURPOSE: </strong>The purpose of this study was to describe patterns of human papillomavirus (HPV) vaccine initiation by males and characterize sociodemographic differences.</p>

<p><strong>METHODS: </strong>We conducted a retrospective cohort study of 11- to 18-year-old males in a large primary care network who had a preventive or acute visit between October 2009 and December 2013. Outcomes measured were HPV vaccine series initiation and initiation at the first eligible visit. Logistic regression measured independent associations between outcomes and sociodemographic characteristics, adjusting for potential confounders including visit frequency, insurance changes, and the presence of complex medical conditions.</p>

<p><strong>RESULTS: </strong>Of 58,757 eligible patients, most were white (57%) with private insurance (77%). During the study period, 39% of the cohort initiated the vaccine series, and 7% initiated at their first eligible visit. Black patients with private (adjusted odds ratio [aOR], 1.99; 95% confidence interval [CI], 1.73-2.30) and Medicaid insurance (aOR, 2.90; 95% CI, 2.56-3.30) had significantly higher odds of HPV vaccine initiation compared with white patients with private insurance. A similar trend was found for Hispanic patients with private (aOR, 1.45; 95% CI, 1.26-1.67) and Medicaid insurance (aOR, 2.15; 95% CI, 1.78-2.60). These differences were present both in the preroutine recommendation period (2009-2011) and the postroutine recommendation period (2012-2013).</p>

<p><strong>CONCLUSIONS: </strong>Traditionally marginalized populations have higher odds of HPV vaccine initiation, both at the first eligible visit and overall. Although the true mechanism underlying these differences remains unknown, potential candidates include provider recommendation patterns and differential vaccine acceptance within these groups.</p>