Comparison of Statistical Methods for Modeling Count Data with an Application to Length of Hospital Stay

Hospital length of stay (LOS) is a key indicator of hospital care management efficiency, cost of care, and hospital planning. Therefore, understanding hospital LOS variability is always an important healthcare focus. Hospital LOS data are count data, with discrete and nonnegative values, typically right-skewed, and often exhibiting excessive zeros. Numerous studies have been conducted to model hospital LOS to identify significant predictors contributing to its variability. Many researchers have used linear regression with or without logarithmic transformation of the outcome variable LOS, or logistic regression on a dichotomized LOS. These regression methods usually violate models’ assumptions and are subject to criticism for their inadequacy in modeling count data. Problems that may occur include biased parameter estimates, loss of precision of inferences, predicting meaningless negative values, and loss of important information about the underlying counts. Common statistical methods for the analysis of count data are Poisson, negative binomial (NB), zero-inflated Poisson (ZIP), and zero-inflated negative binomial (ZINB) regressions. Many studies have been conducted comparing the performance of regression models for count data. However, the results from the analysis of empirical and/or simulated count data are in much disagreement. In this study, we compared the performance of Poisson, NB, ZIP, and ZINB regression models using simulated data under different scenarios with varying sample sizes, proportions of zeros, and levels of overdispersion. To illustrate the aforementioned regression methods, an analysis of hospital LOS was conducted using empirical data from the MIMIC-III database

Comparative spending of medicaid dollars on child participants of Kentucky’s sobriety treatment and recovery teams program versus a matched comparison group.

Child protective services agencies have long observed the complicating role that parental substance use and addiction plays in cases of child maltreatment. Families who struggle with these problems present unique challenges for child welfare professionals. These families are typically more difficult to engage, more likely to have children removed from the home, and have poorer outcomes when compared to other families. These poorer outcomes often include health problems. Addiction has well-known effects on health, and the specific manifestations of these problems for parents have been documented for years in child protection casework. However, what has been less investigated are the ways that these issues correspond to the health of the children involved in these cases. In many instances, children in these homes are severely injured and require acute medical care. These harms commonly result in significant increases in public spending; especially for state Medicaid programs. In Kentucky, the Cabinet for Health and Family Services created special child welfare units called Sobriety Treatment and Recovery Teams (START) to serve families where children have been harmed as a result of their parent’s substance use. Previous research efforts suggest that families who participate in START have more favorable outcomes than comparable families who received standard services. These past efforts have even documented cost savings attributable to the work of START in the form of fewer days spent in out of home care for children. This study aimed to expand on that past research by investigating whether similar costs savings are also being generated in the form of reduced Medicaid spending on the children whose parents received START services

A study of incidence, prevalence, treatment patterns, healthcare utilization, and costs of treatment of Attention Deficit Hyperactivity Disorder (ADHD) among Texas Medicaid preschoolers

Attention Deficit Hyperactivity Disorder (ADHD) is the most common neurobehavioral disorder diagnosed in children and adolescents, affecting approximately 11% of children in the United States in 2011. Children are often diagnosed with ADHD before seven years of age. Yet, there is very little information about the diagnoses, treatments, healthcare utilization, and costs associated with ADHD in preschool children. The American Academy of Pediatrics recommends behavioral therapy as the first-line therapy for preschoolers, with a recommendation to prescribe medications only if behavioral therapy is unsuccessful in alleviating ADHD-related symptoms. For children in elementary school, combination therapy is recommended. Thus, the goal of the current study was to assess the epidemiology (i.e., prevalence and incidence), treatment patterns (i.e., adherence, persistence, augmentation, and switching), healthcare utilization, and costs in preschoolers diagnosed with ADHD using the Texas Medicaid dataset. Patients < 6 years of age diagnosed with ADHD (ICD-9 codes 314.00, 314.01) with continuous enrollment for a 6-month pre-index period and a 12-month post-index period between 2008 and 2013 were identified from the Texas Medicaid dataset. Epidemiology estimates were calculated for all the patients < 6 years of age diagnosed with ADHD. Treatment patterns, healthcare utilization, and costs were estimated for patients between 2 – 6 years of age. Based on the study inclusion criteria, we identified 10,877 patients in the overall cohort. A subsample from the overall cohort was selected for inclusion in the treatment pattern cohort (n = 8,833). The index date for the overall cohort was the ADHD diagnosis date. The index date for the treatment pattern cohort was the date of the first ADHD prescription. Prevalence and incidence estimates were calculated for all the patients < 6 years of age. Time-to-initiation, healthcare utilization, and costs were analyzed using the overall cohort. Treatment pattern outcomes (i.e., adherence, persistence, augmentation, and switching) were evaluated using the treatment pattern cohort. The study sample was further subcategorized into pharmacotherapy only, psychotherapy only, and combination therapy groups. The study covariates included patient demographic (i.e., age, gender, race/ethnicity, and urban/rural status), clinical (i.e., other psychotropics, other mental health diagnosis, medication duration of action, and medication class), and prior utilization (i.e., pre-index total costs, pre-index psychiatric visits, and pre-index non-psychiatric visits) characteristics. Bivariate and multivariate analyses were used to analyze the data. The prevalence of ADHD in preschoolers was estimated to be between 2.1% and 8.5% from years 2008 to 2012. Incidence estimates were stable and were estimated to be between 2.4% and 2.1% from years 2009 to 2012. Medication adherence, augmentation, and switching rates were higher in the combination therapy group as compared to the pharmacotherapy group. The combination therapy group had significantly higher healthcare utilization in all resource utilization categories except ADHD-related prescriptions, other mental health-related office-based, and inpatient visits. Similarly, medical, prescription, and total healthcare costs were also significantly higher in the combination therapy group as compared to the pharmacotherapy group except for the other mental health-related medical costs. In summary, the prevalence and incidence of ADHD in preschoolers is significant. Most of the patients received medication therapy followed by combination therapy and psychotherapy. A comparison of treatments revealed that combination therapy group had a higher healthcare burden as compared to the pharmacotherapy group. This study adds to the existing literature regarding ADHD in preschoolers, from a Medicaid perspective. Also, since Texas Medicaid provides coverage for nearly 50% of children in Texas these results have important implication for the state of Texas. The results of the current study will help identify the more important healthcare utilization and cost categories so as to develop a more targeted intervention approach for patients with ADHD. Further research is needed to understand the long-term effects of pharmacotherapy, psychotherapy, and combination therapy in preschoolers. More evidence is needed to identify the best treatment option for the management of ADHD in preschoolers.Pharmaceutical Science