Designing Difference-in-Difference Studies with Staggered Treatment Adoption: Key Concepts and Practical Guidelines.

Difference-in-difference (DID) estimators are a valuable method for identifying causal effects in the public health researcher's toolkit. A growing methods literature points out potential problems with DID estimators when treatment is staggered in adoption and varies with time. Despite this, no practical guide exists for addressing these new critiques in public health research. We illustrate these new DID concepts with step-by-step examples, code, and a checklist. We draw insights by comparing the simple 2 × 2 DID design (single treatment group, single control group, two time periods) with more complex cases: additional treated groups, additional time periods of treatment, and treatment effects possibly varying over time. We outline newly uncovered threats to causal interpretation of DID estimates and the solutions the literature has proposed, relying on a decomposition that shows how the more complex DIDs are an average of simpler 2 × 2 DID subexperiments.

Ketoreductase-Catalyzed Access to Axially Chiral 2,6-Disubstituted Spiro[3.3]heptane Derivatives.

The desymmetrization of a prochiral 6-oxaspiro[3.3]heptane-2-carboxylic acid derivative via biocatalytic ketoreductase-mediated reduction has provided access to both enantiomers in high ee. The axially chiral alcohol was converted to the corresponding ester alcohol, amino acid, and amino alcohol building blocks while high enantiopurity was maintained.

Strategic use of health information exchange and market share, payer mix, and operating margins.

BACKGROUND: Health information exchange (HIE) capabilities are tied to health care organizations' strategic and business goals. As a technology that connects information from different organizations, HIE may be a source of competitive advantage and a path to improvements in performance. PURPOSE: The aim of the study was to identify the impact of hospitals' use of HIE capabilities on outcomes that may be sensitive to changes in various contracting arrangements and referral patterns arising from improved connectivity. METHODOLOGY: Using a panel of community hospitals in nine states, we examined the association between the number of different data types the hospital could exchange via HIE and changes in market share, payer mix, and operating margin (2010-2014). Regression models that controlled for the number of different data types shared intraorganizationally and other time-varying factors and included both hospital and time fixed effects were used for adjusted estimates of the relationships between changes in HIE capabilities and outcomes. RESULTS: Increasing HIE capability was associated with a 13 percentage point increase in a hospital's discharges that were covered by commercial insurers or Medicare (i.e., payer mix). Conversely, increasing intraorganizational information sharing was associated with a 9.6 percentage point decrease in the percentage of discharges covered by commercial insurers or Medicare. Increasing HIE capability or intraorganizational information sharing was not associated with increased market share nor with operating margin. CONCLUSIONS: Improving information sharing with external organizations may be an approach to support strategic business goals. PRACTICE IMPLICATIONS: Organizations may be served by identifying ways to leverage HIE instead of focusing on intraorganizational exchange capabilities.

Docs with their eyes on the clock? The effect of time pressures on primary care productivity.

This paper examines how time pressure, an important constraint faced by medical care providers, affects productivity in primary care. We generate empirical predictions by incorporating time pressure into a model of physician behavior by Tai-Seale and McGuire (2012). We use data from the electronic health records of a large integrated delivery system and leverage unexpected schedule changes as variation in time pressure. We find that greater time pressure reduces the number of diagnoses recorded during a visit and increases both scheduled and unscheduled follow-up care. We also find some evidence of increased low-value care, decreased preventive care, and decreased opioid prescribing.

Association Between Medicaid Expansion and Rates of Opioid-Related Hospital Use.

Importance: The rate of opioid-related emergency department (ED) visits and inpatient hospitalizations has increased rapidly in recent years. Medicaid expansions have the potential to reduce overall opioid-related hospital events by improving access to outpatient treatment for opioid use disorder. Objective: To examine the association between Medicaid expansions and rates of opioid-related ED visits and inpatient hospitalizations. Design, Setting, and Participants: A difference-in-differences observational design was used to compare changes in opioid-related hospital events in US nonfederal, nonrehabilitation hospitals in states that implemented Medicaid expansions between the first quarter of 2005 and the last quarter of 2017 with changes in nonexpansion states. All-payer ED and hospital discharges from 45 states in the Healthcare Cost and Utilization Project FastStats were included. Exposures: State implementation of Medicaid expansions between 2005 and 2017. Main Outcomes and Measures: Rates of all opioid-related ED visits and inpatient hospitalizations, measured as the quarterly numbers of treat-and-release ED discharges and hospital discharges related to opioid abuse, dependence, and overdose, per 100 000 state population. Results: In the 46 states and District of Columbia included in the study, 1524 observations of emergency department data and 2219 observations of opioid-related inpatient hospitalizations were analyzed. The post-2014 Medicaid expansions were associated with a 9.74% (95% CI, -18.83% to -0.65%) reduction in the rate of opioid-related inpatient hospitalizations. There appeared to be no association between the pre-2014 or post-2014 Medicaid expansions and the rate of opioid-related ED visits (post-2014 Medicaid expansions, -3.98%; 95% CI, -14.69% to 6.72%; and pre-2014 Medicaid expansions, 1.02%; 95% CI, -5.25% to 7.28%). Conclusions and Relevance: Medicaid expansion appears to be associated with meaningful reductions in opioid-related hospital use, possibly attributable to improved care for opioid use disorder in other settings.

Synthesis and direct comparison of the anticancer activities of phomopsolides D and E and two 7-oxa-/7-aza-analogues.

The synthesis of two stable phomopsolide natural products (D and E) and two analogues is presented. The cytotoxicities of these four compounds are surveyed and compared across a panel of NCI-cancer cell lines. This analysis found moderate cytotoxicities (2-50 µM) for the majority of the cell lines with phomopsolide D being more active than phomopsolide E and the 7-oxa analogue being commensurately more active than the 7-aza analogue.

Electronic medical records and medical procedure choice: Evidence from cesarean sections.

This paper examines how hospital adoption of electronic medical records (EMRs) impacts medical procedure choice in the context of cesarean section deliveries. It provides a unique contribution by tying the literature on EMR diffusion to the literature on the utilization of expensive medical technology and provider practice style. Exploiting within-hospital variation in three types of EMR adoption, we find that computerized physician order entry, an advanced EMR system that typically incorporates decision support, reduces C-section rates for low-risk mothers by 2.5%. Obstetric-specific EMR systems and physician documentation have no statistically significant effect on C-section rates. In addition, we find that the computerized practitioner order entry effect occurs predominantly in hospitals that were already performing fewer C-sections and does not change the behavior of already high-intensity providers.

Health systems' use of enterprise health information exchange vs single electronic health record vendor environments and unplanned readmissions.

OBJECTIVE: Enterprise health information exchange (HIE) and a single electronic health record (EHR) vendor solution are 2 information exchange approaches to improve performance and increase the quality of care. This study sought to determine the association between adoption of enterprise HIE vs a single vendor environment and changes in unplanned readmissions. MATERIALS AND METHODS: The association between unplanned 30-day readmissions among adult patients and adoption of enterprise HIE or a single vendor environment was measured in a panel of 211 system-member hospitals from 2010 through 2014 using fixed-effects regression models. Sample hospitals were members of health systems in 7 states. Enterprise HIE was defined as self-reported ability to exchange information with other members of the same health system who used different EHR vendors. A single EHR vendor environment reported exchanging information with other health system members, but all using the same EHR vendor. RESULTS: Enterprise HIE adoption was more common among the study sample than EHR (75% vs 24%). However, adoption of a single EHR vendor environment was associated with a 0.8% reduction in the probability of a readmission within 30 days of discharge. The estimated impact of adopting an enterprise HIE strategy on readmissions was smaller and not statically significant. CONCLUSION: Reductions in the probability of an unplanned readmission after a hospital adopts a single vendor environment suggests that HIE technologies can better support the aim of higher quality care. Additionally, health systems may benefit more from a single vendor environment approach than attempting to foster exchange across multiple EHR vendors.

Do Crowdsourced Hospital Ratings Coincide with Hospital Compare Measures of Clinical and Nonclinical Quality?

OBJECTIVE: To determine the consistency with which government-issued hospital quality ratings and crowdsourced ratings on social media sites identify hospital quality. DATA SOURCES: Hospital ratings from Facebook, Google, and Yelp were linked with Hospital Compare (HC) measures. STUDY DESIGN: Fixed-effects linear regression model. PRINCIPAL FINDINGS: Among crowdsourcing sites' best-ranked hospitals, 50-60% were also the best ranked on HC's overall and patient experience ratings; 20% ranked as the worst. Best-ranked hospitals had significantly better clinical quality scores than worst ranked hospitals, but were not more likely to be the highest rated in terms of HC's clinical quality measures alone. CONCLUSIONS: Crowdsourcing sites and HC provide comparable information on patient experience; scores were less consistent in terms of risk-adjusted measures of patient safety and clinical quality.

Learning From Waiver States: Coverage Effects Under Indiana's HIP Medicaid Expansion.

In 2015, Indiana expanded eligibility for Medicaid under the Affordable Care Act (ACA) through a unique waiver, Healthy Indiana Plan 2.0, which requires enrollees to make monthly contributions to an account that is similar to a health savings account to receive full benefits. Enrollees who fail to make these contributions receive less generous benefits if their income is below the federal poverty level, and if it is 100-138 percent of poverty, they are locked out of coverage for six months. We estimated the impact of this expansion on coverage rates and compared the effects to results from other states that expanded Medicaid after 2014. We found that Indiana's coverage gains (relative to pre-ACA uninsurance rates) were smaller than gains in neighboring expansion states, but larger than those in other states. These results imply that while one potential reason for Indiana's lower gains relative to neighboring states was its cost-sharing requirements, expansion led to unquestionable coverage gains in the state.

Stereochemical Sequence Dictates Unimolecular Diblock Copolymer Assembly.

Deciphering the significance of length, sequence, and stereochemistry in block copolymer self-assembly remains an ongoing challenge. A dearth of methods to access uniform block co-oligomers/polymers with precise stereochemical sequences has precluded such studies. Here, we develop iterative exponential growth methods for the synthesis of a small library of unimolecular stereoisomeric diblock 32-mers. X-ray scattering reveals that stereochemistry modulates the phase behavior of these polymers, which we rationalize based on simulations carried out on a theoretical model system. This work demonstrates that stereochemical sequence can play a crucial role in unimolecular polymer self-assembly.

Changes in inpatient payer-mix and hospitalizations following Medicaid expansion: Evidence from all-capture hospital discharge data.

CONTEXT: The Affordable Care Act resulted in unprecedented reductions in the uninsured population through subsidized private insurance and an expansion of Medicaid. Early estimates from the beginning of 2014 showed that the Medicaid expansion decreased uninsured discharges and increased Medicaid discharges with no change in total discharges. OBJECTIVE: To provide new estimates of the effect of the ACA on discharges for specific conditions. DESIGN, SETTING, AND PARTICIPANTS: We compared outcomes between states that did and did not expand Medicaid using state-level all-capture discharge data from 2009-2014 for 42 states from the Healthcare Costs and Utilization Project's FastStats database; for a subset of states we used data through 2015. We stratified the analysis by baseline uninsured rates and used difference-in-differences and synthetic control methods to select comparison states with similar baseline characteristics that did not expand Medicaid. MAIN OUTCOME: Our main outcomes were total and condition-specific hospital discharges per 1,000 population and the share of total discharges by payer. Conditions reported separately in FastStats included maternal, surgical, mental health, injury, and diabetes. RESULTS: The share of uninsured discharges fell in Medicaid expansion states with below (-4.39 percentage points (p.p.), -6.04 --2.73) or above (-7.66 p.p., -9.07 --6.24) median baseline uninsured rates. The share of Medicaid discharges increased in both small (6.42 p.p. 4.22-6.62) and large (10.5 p.p., 8.48-12.5) expansion states. Total and most condition-specific discharges per 1,000 residents did not change in Medicaid expansion states with high or low baseline uninsured rates relative to non-expansion states (0.418, p = 0.225), with one exception: diabetes. Discharges for that condition per 1,000 fell in states with high baseline uninsured rates relative to non-expansion states (-0.038 95% p = 0.027). CONCLUSIONS: Early changes in payer mix identified in the first two quarters of 2014 continued through the Medicaid expansion's first year and are distributed across all condition types studied. We found no change in total discharges between Medicaid expansion and non-expansion states, however residents of states that should have been most affected by the Medicaid expansion were less likely to be hospitalized for diabetes.

Effect of the Affordable Care Act Medicaid Expansion on Emergency Department Visits: Evidence From State-Level Emergency Department Databases.

STUDY OBJECTIVE: We assess whether the expansion of Medicaid under the Patient Protection and Affordable Care Act (ACA) results in changes in emergency department (ED) visits or ED payer mix. We also test whether the size of the change in ED visits depends on the change in the size of the Medicaid population. METHODS: Using all-capture, longitudinal, state data from the Agency for Healthcare Research and Quality's Fast Stats program, we implemented a difference-in-difference analysis, which compared changes in ED visits per capita and the share of ED visits by payer (Medicaid, uninsured, and private insurance) in 14 states that did and 11 states that did not expand Medicaid in 2014. Analyses controlled for state-level demographic and economic characteristics. RESULTS: We found that total ED use per 1,000 population increased by 2.5 visits more in Medicaid expansion states than in nonexpansion states after 2014 (95% confidence interval [CI] 1.1 to 3.9). Among the visit types that could be measured, increases in ED visits were largest for injury-related visits and for states with the largest changes in Medicaid enrollment. Compared with nonexpansion states, in expansion states the share of ED visits covered by Medicaid increased 8.8 percentage points (95% CI 5.0 to 12.6), whereas the uninsured share decreased by 5.3 percentage points (95% CI -1.7 to -8.9). CONCLUSION: The ACA's Medicaid expansion has resulted in changes in payer mix. Contrary to other studies of the ACA's effect on ED visits, our study found that the expansion also increased use of the ED, consistent with polls of emergency physicians.

Capacity and Utilization in Health Care: The Effect of Empty Beds on Neonatal Intensive Care Admission.

Because geographic variation in medical care utilization is jointly determined by both supply and demand, it is difficult to empirically estimate whether capacity itself has a causal impact on utilization in health care. In this paper, I exploit short-term variation in Neonatal Intensive Care Unit (NICU) capacity that is unlikely to be correlated with unobserved demand determinants. I find that available NICU beds have little to no effect on NICU utilization for the sickest infants, but do increase utilization for those in the range of birth weights where admission decisions are likely to be more discretionary.

Health insurance and hospital technology adoption.

PURPOSE: This chapter discusses the relationship between health insurance and hospitals' decisions to adopt medical technologies. I focus on both how the extent of insurance coverage can increase incentives to adopt new treatments, and how the parameters of the insurance contract can impact the types of treatments adopted. METHODOLOGY/APPROACH: I provide a review of the previous theoretical and empirical literature and highlight evidence on this relationship from previous expansions of Medicaid eligibility to low-income pregnant women. FINDINGS: While health insurance has important effects on individual-level choices of health care consumption, increases in the fraction of the population covered by insurance has also been found to have broader supply side effects as hospitals respond to changes in demand by changing the type of care offered. Furthermore, hospitals respond to the design of insurance contracts and adopt more or less cost-effective technologies depending on the incentive system. RESEARCH LIMITATIONS/IMPLICATIONS: Understanding how insurance changes supply side incentives is important as we consider future changes in the insurance landscape. ORIGINALITY/VALUE OF PAPER: With these previous findings in mind, I conclude with a discussion of how the Affordable Care Act may alter hospital technology adoption incentives by both expanding coverage and changing payment schemes.