A Bayesian zero-inflated beta-binomial model for longitudinal data with group-specific changepoints.

Timeline followback (TLFB) is often used in addiction research to monitor recent substance use, such as the number of abstinent days in the past week. TLFB data usually take the form of binomial counts that exhibit overdispersion and zero inflation. Motivated by a 12-week randomized trial evaluating the efficacy of varenicline tartrate for smoking cessation among adolescents, we propose a Bayesian zero-inflated beta-binomial model for the analysis of longitudinal, bounded TLFB data. The model comprises a mixture of a point mass that accounts for zero inflation and a beta-binomial distribution for the number of days abstinent in the past week. Because treatment effects appear to level off during the study, we introduce random changepoints for each study group to reflect group-specific changes in treatment efficacy over time. The model also includes fixed and random effects that capture group- and subject-level slopes before and after the changepoints. Using the model, we can accurately estimate the mean trend for each study group, test whether the groups experience changepoints simultaneously, and identify critical windows of treatment efficacy. For posterior computation, we propose an efficient Markov chain Monte Carlo algorithm that relies on easily sampled Gibbs and Metropolis-Hastings steps. Our application shows that the varenicline group has a short-term positive effect on abstinence that tapers off after week 9.

Feeding Performance and Outcomes in Infants With Robin Sequence Undergoing Mandibular Distraction Osteogenesis.

To describe perioperative feeding performance in infants with Robin sequence (RS) who underwent mandibular distraction osteogenesis (MDO).A retrospective study of infants that underwent MDO from May 2010 to December 2019.Tertiary pediatric hospital.A total of 40 patients underwent MDO and 20 met inclusion criteria. Of the included infants, 6 had an associated syndrome and 80% were male.Time to full oral feeds, rate of G-tube placement, and change in weight percentile following MDO.Average oral intake prior to MDO was 22.1% of individual goal feeds. Among the 15 (75%) children that did not require G-tube placement, mean time to full oral feeds after MDO was 11 days ± 5.7 days, with 80% of infants reaching full oral feeds within 2 weeks after extubation. The proportion of G-tube placement in patients with a syndrome was higher than in isolated RS (-0.6; 95% CI: -1.0, -0.2). Mean percentages of weight-for-age percentile decreased during the first 3 months after the procedure. This was followed by a mean upturn in weight starting after the third month after MDO with a recovery to preoperative mean weight-for-age percentiles by 6 months after surgery.This study suggests that infants with RS may achieve full oral feeds despite poor feeding performance before MDO. Infants with syndromic RS are more likely to require G-tube. These findings may be used to inform G-tube discussion and offer a timeline to work toward goal oral feeds for infants with RS after MDO.

Rural Barriers to Surgical Care for Children With Sleep-Disordered Breathing.

OBJECTIVE: To assess the impact of rural-urban residence on children with obstructive sleep-disordered breathing (SDB) who were candidates for tonsillectomy with or without adenoidectomy (TA). STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary children's hospital. METHODS: A cohort of otherwise healthy children aged 2 to 18 years with a diagnosis of obstructive SDB between April 2016 and December 2018 who were recommended TA were included. Rural-urban designation was defined by ZIP code approximation of rural-urban commuting area codes. The main outcome was association of rurality with time to TA and loss to follow-up using Cox and logistic regression analyses. RESULTS: In total, 213 patients were included (mean age 6 ± 2.9 years, 117 [55%] male, 69 [32%] rural dwelling). Rural-dwelling children were more often insured by Medicaid than private insurance (P < .001) and had a median driving distance of 74.8 vs 16.8 miles (P < .001) compared to urban-dwelling patients. The majority (94.9%) eventually underwent recommended TA once evaluated by an otolaryngologist. Multivariable logistic regression analysis did not reveal any significant predictors for loss to follow-up in receiving TA. Cox regression analysis that adjusted for age, sex, insurance, and race showed that rural-dwelling patients had a 30% reduction in receipt of TA over time as compared to urban-dwelling patients (hazard ratio, 0.7; 95% CI, 0.50-0.99). CONCLUSION: Rural-dwelling patients experienced longer wait times and driving distance to TA. This study suggests that rurality should be considered a potential barrier to surgical intervention and highlights the need to further investigate geographic access as an important determinant of care in pediatric SDB.

Correlates of response and outcomes with talimogene laherperpvec.

BACKGROUND AND OBJECTIVES: Patients with in-transit or limited cutaneous metastatic melanoma may benefit from intralesional injections with talimogene laherparepvec (TVEC), a modified oncolytic herpesvirus. However, its use in patients with adverse prognostic scores in a real-life clinical setting has not been studied. METHODS: We performed a two-center retrospective analysis of 40 patients with metastatic melanoma treated with TVEC from 2015-2017. Demographics, overall response, and survival after therapy were noted. RESULTS: Overall, there was a durable response rate of 40%; median progression-free survival (PFS) was 10.5 months and median overall survival (OS) was not reached. Bulky disease was associated with decreased OS (15.7 months vs not reached, P < .05) and mPFS (2.3 months vs not reached, P < .05), when compared with smaller tumors. Poor performance status (ECOG 2-3) was associated with worse OS (10.2 months vs not reached, P < .05) and PFS (2.1 months vs not reached, P < .05) compared to patients with ECOG 0-1. There was no difference in the outcomes with age greater than 75 or with prior therapies. Adverse events were relatively tolerable. CONCLUSIONS: These findings demonstrate that TVEC is an effective and safe treatment for metastatic melanoma in a real-life clinical setting, and suggest parameters to aid in appropriate therapy selection for optimal response.