Tianyan Hu

Exogenous predictors of national performance measures for emergency department crowding.

STUDY OBJECTIVE We explore the relationship between exogenous-level predictors and performance on 4 emergency department (ED) throughput measures approved by the National Quality Forum: median ED length of visit for admitted and discharged patients, median waiting time, and rate of left without being seen. We seek to find predictors for benchmarking and public reporting. METHODS This was a study of 424 US hospitals that reported data to the National Hospital Ambulatory Care Survey in 2008 to 2009. Wald F tests and generalized linear models were used to test the relationship between exogenous variables (case mix, age mix, ED volume, teaching status, and Metropolitan Statistical Area status) and performance on the measures. RESULTS Median waiting time was 35 minutes (95% confidence interval [CI] 26 to 43 minutes), median length of visit for patients treated but not admitted was 131 minutes (95% CI 121 to 142 minutes), median length of visit for patients admitted was 244 minutes (95% CI 218 to 270 minutes), and rate of left without being seen was 1.3% (95% CI 0.9% to 1.8%). Most exogenous variables, including ED volume, Metropolitan Statistical Area, teaching hospital status, age mix, and case mix, demonstrated significant association with waiting times and lengths of visit. Older age and a higher proportion of respiratory complaints were associated with differences in rates of left without being seen. CONCLUSION Several exogenous factors outside of a hospitals control are associated with National Quality Forum-approved ED performance measures, which will have important implications for future benchmarking and public reporting of these data.

The Impact of Health Insurance Expansion on Physician Treatment Choice: Medicare Part D and Physician Prescribing

We test the effect of the introduction of Medicare Part D on physician prescribing behavior by using data on physician visits from the National Ambulatory Medical Care Survey (NAMCS) 2002–2004 and 2006–2009 for patients aged 60–69. We use regression discontinuity designs to estimate the effect of part D around the age of 65 before and after 2006 and then compare the discrete jump in outcomes at age 65 before and after Part D. We find a 32% increase in the number of prescription drugs prescribed or continued per visit and a 46% increase in the number of generic drugs prescribed or continued for the elderly after the introduction of Medicare Part D.

A mixed methods study of clinical information availability in obstetric triage and prenatal offices

Objective: To determine the effect of availability of clinical information from an integrated electronic health record system on pregnancy outcomes at the point of care. Materials and methods: We used provider interviews and surveys to evaluate the availability of pregnancy-related clinical information in ambulatory practices and the hospital, and applied multiple regression to determine whether greater clinical information availability is associated with improvements in pregnancy outcomes and changes in care processes. Our regression models are risk adjusted and include physician fixed effects to control for unobservable characteristics of physicians that are constant across patients and time. Results: Making nonstress test results, blood pressure data, antenatal problem lists, and tubal sterilization requests from office records available to hospital-based providers is significantly associated with reductions in the likelihood of obstetric trauma and other adverse pregnancy outcomes. Better access to prenatal records also increases the probability of labor induction and decreases the probability of Cesarean section (C-section). Availability of lab test results and new diagnoses generated in the hospital at ambulatory offices is associated with fewer preterm births and low-birth-weight babies. Discussion and conclusions: Increased availability of specific clinical information enables providers to deliver better care and improve outcomes, but some types of clinical data are more important than others. More available information does not always result from automated integration of electronic records, but rather from the availability of the source records. Providers depend upon information that they trust to be reliable, complete, consistent, and easily retrievable, even if this requires multiple interfaces.

Medicaid Pay for Performance Programs and Childhood Immunization Status

INTRODUCTION Although pay for performance (P4P) programs are being increasingly used by state Medicaid programs to provide incentives for managed care plans to provide high-quality care, no national study has examined the effects of these plans on commonly targeted outcomes such as childhood immunization rates. METHODS Information from the 1999-2011 National Immunization Survey combined with information on state Medicaid P4P programs from the Centers for Medicare and Medicaid Services was used to study the effect of Medicaid P4P programs on the immunization status of children aged 19-35 months. Difference-in-difference-in-difference models were used to study whether adoption of Medicaid P4P programs was associated with higher immunization rates among Medicaid-eligible children relative to non-Medicaid eligible children within states that adopted Medicaid P4P programs compared with states that did not. Linear probability models were used in all estimations, and models controlled for demographic factors. RESULTS The study found no overall effect of Medicaid P4P on the chance that children aged 19-35 months had completed the 4:3:1:3:3:1 vaccination series. However, there was a 4 percentage point increase in the chance that a child 19-23 months had completed the series. CONCLUSIONS This study provides some evidence that Medicaid P4P programs may be helpful in improving childhood vaccination rates. Further study of the effects on other targeted outcomes as well as the effects of different P4P program designs may increase understanding of the potential role of these programs in improving the quality of health care.

Self-reported Health Status Differs for Amazon's Mechanical Turk Respondents Compared with Nationally Representative Surveys

Background: Amazon’s Mechanical Turk (MTurk) platform has become a data source for peer-reviewed academic research publications, with over 24,000 Google Scholar search results. Although well-developed and supportive in other disciplines, the literature in health and medicine comparing results from samples generated on MTurk to gold standard, nationally representative health and medical surveys is beginning to emerge. Objective: To compare the demographic, socioeconomic, and self-reported health status variables in an MTurk sample to those from 2 prominent national probability surveys, including the Medical Expenditure Panel Survey (MEPS) and the Behavioral Risk Factor Surveillance System (BRFSS). Research Design: We analyze weighted and unweighted tabulations of the MTurk, MEPS, and BRFSS. Wald tests identify statistical significance. Measures: Demographic, socioeconomic, and health status variables in an adult MTurk sample collected in 2016 (n=1916), the 2015 MEPS household survey component (n=21,210), and the 2015 BRFSS (n=283,502). Results: Our findings indicate statistically significant differences in the demographic, socioeconomic, and self-perceived health status tabulations in the MTurk sample relative to the unweighted and weighted MEPS and BRFSS. The MTurk sample is more likely to be female (65.8% in MTurk, 50.9% in MEPS, 50.2% in BRFSS), white (80.1% in MTurk, 76.9% in MEPS, and 73.9% in BRFSS), non-Hispanic (91.1%, 82.4%, and 81.4%, respectively), younger, and less likely to report excellent health status (6.8% in MTurk, 28.3% in MEPS, and 20.2% in BRFSS). Conclusions: We find significant differences across variables that warrant hesitation in using MTurk data as a replacement for the gold standard datasets in health services research.

Mandatory Statewide Medicaid Managed Care in Florida and Hospitalizations for Ambulatory Care Sensitive Conditions

OBJECTIVE To investigate the impact of implementation of the Statewide Medicaid Managed Care (SMMC) program in Florida on access to and quality of primary care for Medicaid enrollees, measured by hospitalizations for ambulatory care sensitive conditions (ACSCs). DATA SOURCES We examine inpatient data obtained from the Agency for Health Care Administration for 285 hospitals in Florida from January 2010 to June 2015. The analysis includes 3,645,515 discharges for Florida residents between the ages 18 and 64 with a primary payer of Medicaid or private insurance. STUDY DESIGN We use a difference-in-differences approach, comparing the change in the incidence of ACSC-related inpatient visits among Medicaid patients before and after the implementation of SMMC, relative to the change among the privately insured. PRINCIPAL FINDINGS After implementation of SMMC, Medicaid patients experienced a 0.35 percentage point slower growth in overall ACSC-related inpatient visits, and a 0.21 percentage point slower growth in chronic ACSC-related inpatient visits. The effects were significant in counties with above median Medicaid managed care penetration rates. CONCLUSIONS Implementing mandatory managed care in Medicaid in Florida leads to slower growth in inpatient visits for conditions that can potentially be prevented with improved access to outpatient care.