Incremental Hospital Costs Associated With Comorbidities of Prematurity

PURPOSE

Preterm birth (PTB), defined as birth at a gestational age (GA) of less than 37 weeks, is associated with increased hospital costs. Lower GA at birth is negatively correlated with the presence of neonatal comorbidities, further increasing costs. This study evaluated incremental costs associated with comorbidities of PTB following spontaneous labor at 24-36 weeks.

DESIGN

Birth records from January 2001 to December 2010 at the Medical University of South Carolina were screened to identify infants born at GA 23-37 weeks after uncomplicated singleton pregnancies and surviving to discharge.

METHODOLOGY

Comorbidities of interest and incremental costs were analyzed with a partial least squares (PLS) regression model adjusted for comorbidities and GA. Incremental comorbidity-associated costs, as well as total costs, were estimated for infants of GA 24-36 weeks.

RESULTS

A total of 4,292 delivery visit records were analyzed. Use of the PLS regression model eliminated issues of multicollinearity and allowed derivation of stable cost estimates. Incremental costs of comorbidities at a mean GA of 34 weeks ranged from $4,529 to $23,121, and exceeded $9,000 in 6 cases. Incremental costs rangedfrom a high of $41,161 for a GA 24-week infant with a comorbidity of retinopathy of prematurity requiring surgery (ROP4) to $3,683 for a GA 36-week infant with a comorbidity of convulsions. Incremental comorbidity costs are additive, so the costs for infants with multiple comorbidities could easily exceed the high of $41,161 seen with ROP4.

CONCLUSIONS

The PLS regression model allowed derivation of stable cost estimates from multivariate and highly collinear data and can be used in future cost analyses. Using this data set, predicted costs of all comorbidities, as well as total costs, negatively correlated with GA at birth.

Persistence and compliance with pazopanib in patients with advanced renal cell carcinoma within a U.S. administrative claims database

BACKGROUND

Pazopanib is an oral tyrosine kinase inhibitor with demonstrated efficacy and tolerability in patients with advanced renal cell carcinoma (RCC).

OBJECTIVE

To examine pazopanib persistence and compliance (adherence) and other drug utilization patterns in both treatment-naïve (first-line) patients and those previously treated with RCC therapy in the real-world setting. Key factors affecting persistence and compliance were also explored.

METHODS

This was a retrospective claims analysis using the Truven Health MarketScan Databases to cover claims activity from October 2007 through March 2012. Patients with advanced RCC aged ≥ 18 years who had received pazopanib with 180 days of follow-up were included. Bivariate comparisons of results from first-line and previously treated patients with RCC were conducted. Pazopanib persistence was measured using (a) estimated level of persistence with therapy (ELPT; i.e., the percentage of patients remaining on therapy at 30, 60, and 90 days [patients were censored at 180 days]); (b) time to discontinuation (i.e., duration of therapy); and (c) proportion of days covered (PDC; i.e., the ratio of [total days drug available minus days' supply of last prescription] to [last prescription date minus first prescription date]). Compliance was measured by medication possession ratio (MPR; i.e., the ratio of [total days' supply minus days' supply of last prescription] to [last prescription date minus first prescription date]). Other drug utilization measures included days' supply, time to initiation, time to switching, and dose-related measures. Random forest models were used to explore key factors of pazopanib persistence and compliance.

RESULTS

A total of 143 patients met all inclusion criteria; 43.3% were treated with pazopanib first line (first-line cohort), and 56.6% had ≥ 1 prior lines of therapy (previously treated cohort). The mean (± standard deviation [SD]) age of patients was 62.9 (± 10.3) years, and 71.3% of them were males. Continuous pazopanib therapy for up to 90 days was observed in greater than 50% of patients in both cohorts. In the first-line cohort, ELPT at 30, 60, and 90 days was 98.39%, 70.97%, and 56.45%, respectively; the mean (± SD) number of days to discontinuation was 112.2 (± 62.8); the mean (± SD) PDC was 84.7% (± 16.7%); and the mean (± SD) MPR was 85.2% (± 16.9%). Similar results were observed in the previously treated population: ELPT at 30, 60, and 90 days was 98.77%, 75.31%, and 58.02%, respectively; the mean (± SD) number of days to discontinuation was 118.7 (± 61.4); the mean (± SD) PDC was 87.8% (± 13.5%); and the mean (± SD) MPR was 90.1% (± 13.9%). Differences between the 2 cohorts were not statistically significant. More than 90% of patients in both cohorts had at least a 30-day supply of therapy (91.9% of first-line versus 90.2% of previously treated; P = 0.153). The mean (± SD) time from metastatic diagnosis to start of pazopanib therapy was 104.7 (± 199.3) days in the first-line cohort and 360.9 (± 187.0) days in previously treated patients (P = 0.001). Forty-six patients switched to another therapy: 17 patients in the first-line cohort and 29 patients in the previously treated cohort; the mean (± SD) time to switching therapy from each cohort was 94.7 (± 41.4) days and 87.8 (± 49.6) days (P = 0.146), respectively. Statistically significant differences were observed for the starting and ending doses between the 2 cohorts. The average daily dosage of pazopanib was greater than 700 mg in both cohorts (P = 0.055), with a maximum dose of 800 mg. Random forest models demonstrated that younger age and higher comorbidity predicted both higher persistence and compliance.

CONCLUSIONS

In this observational study, greater than 50% of patients with advanced RCC were on pazopanib for almost 4 months, with the majority of both cohorts achieving high persistence and high compliance. Additionally, younger age and higher comorbidity index were the strongest predictors of both greater persistence and compliance. Further studies with larger cohorts and longer follow-up are needed to validate these findings.

Near-Atomic Resolution Imaging of Ferroelectric Liquid Crystal Molecules on Graphite by STM

Near-atomic resolution images of a two-dimensional heteroepitaxial crystal composed of the relatively "functionally rich" chiral liquid crystal mesogen MDW 74 on graphite have been obtained by scanning tunneling microscopy (STM). This work is aimed at developing an improved understanding of the commercially crucial phenomenon of liquid crystal alignment by studying well-characterized surfaces. Herein is reported molecular-level characterization of the surface underlying a ferroelectric liquid crystal in situ, a requisite starting point for understanding the liquid crystal-solid interface at the molecular level. The results are also important in the context of developing a model for the molecular. origins of the contrast observed in STM images of organic monolayers on conductor surfaces. The data and analysis provide strong evidence that neither frontier orbital alone (highest occupied or lowest unoccupied molecular orbital) is sufficient to describe the observed tunneling efficiency.