HCUPnet is an online data tool based on data from the Healthcare Cost and Utilization Project (HCUP). The data tool provides healthcare statistics and information for hospital inpatient and emergency department settings, as well as population-based healthcare data on counties. Users are able to query HCUP data to access detailed or summary statistics on inpatient stays and emergency department visits by patient, hospital, and encounter characteristics. Users are also able to generate tables and graphs on national and regional statistics and trends for community hospitals in the United States.

HCUPnet is an on-line query system that provides free, instant access to the largest set of all-payer health care databases that are publicly available. Using HCUPnet's easy step-by-step query system, you can generate tables and graphs on statistics and trends for acute care hospitals in the U.S. HCUPnet provides:  National and regional estimates for inpatient stays and emergency department visits;  State counts of inpatient stays and emergency department visits for those states that agreed to participate;  National estimates on readmissions and readmission rates;  County-level statistics on hospital use and potentially preventable admissions, based on the AHRQ Quality Indicators (QIs)* For most queries, detailed information is available for conditions and procedures (by ICD-9-CM codes and Clinical Classification Software), and for diagnosis related groups (DRGs). HCUPnet allows easy access to information from datasets that are part of the Healthcare Cost and Utilization Project (HCUP); details on obtaining these datasets are also available in www.healthdata.gov

Description of the covariate used, with a citation to explain the inclusion, in both the initial OLS screening and the fixed effects regression analysis for Models 1 and 2.

There has been considerable international study on the etiology of rising mental disorders, such as attention-deficit hyperactivity disorder (ADHD), in human populations. As glyphosate is the most commonly used herbicide in the world, we sought to test the hypothesis that glyphosate use in agriculture may be a contributing environmental factor to the rise of ADHD in human populations. State estimates for glyphosate use and nitrogen fertilizer use were obtained from the U.S. Geological Survey (USGS). We queried the Healthcare Cost and Utilization Project net (HCUPNET) for state-level hospitalization discharge data in all patients for all-listed ADHD from 2007 to 2010. We used rural-urban continuum codes from the USDA-Economic Research Service when exploring the effect of urbanization on the relationship between herbicide use and ADHD. Least squares dummy variable (LSDV) method and within method using two-way fixed effects was used to elucidate the relationship between glyphosate use and all-listed ADHD hospital discharges. We show that a one kilogram increase in glyphosate use, in particular, in one year significantly positively predicts state-level all-listed ADHD discharges, expressed as a percent of total mental disorders, the following year (coefficient = 5.54E-08, p