Instrumental variable estimation for functional concurrent regression models.

In this work we propose a functional concurrent regression model to estimate labor supply elasticities over the years 1988 through 2014 using Current Population Survey data. Assuming, as is common, that individuals' wages are endogenous, we introduce instrumental variables in a two-stage least squares approach to estimate the desired labor supply elasticities. Furthermore, we tailor our estimation method to sparse functional data. Though recent work has incorporated instrumental variables into other functional regression models, to our knowledge this has not yet been done in the functional concurrent regression model, and most existing literature is not suited for sparse functional data. We show through simulations that this two-stage least squares approach greatly eliminates the bias introduced by a naive model (i.e. one that does not acknowledge endogeneity) and produces accurate coefficient estimates for moderate sample sizes.

Suicide among college students in psychotherapy: Individual predictors and latent classes.

This study sought to identify predictors of suicidal behavior among college students who are psychotherapy clients, as well as to determine underlying classes of clients with suicidal ideation. Data were gathered from 101,570 clients, 391 of whom engaged in suicide behavior during treatment. Regression analyses revealed that suicide behavior was positively associated with 3 pretreatment variables: depression, prior suicide behavior, and prior nonsuicidal self-injury. Four latent classes of clients with suicidal ideation were identified that were named "prior ideation," "extensive risk," "prior treatment," and "circumscribed depression." The number of clients in each class varied widely, as did the relative risk of suicide behavior. Implications for treatment, suicide assessment, and suicide prevention are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Scalar-on-function regression for predicting distal outcomes from intensively gathered longitudinal data: Interpretability for applied scientists.

Researchers are sometimes interested in predicting a distal or external outcome (such as smoking cessation at follow-up) from the trajectory of an intensively recorded longitudinal variable (such as urge to smoke). This can be done in a semiparametric way via scalar-on-function regression. However, the resulting fitted coefficient regression function requires special care for correct interpretation, as it represents the joint relationship of time points to the outcome, rather than a marginal or cross-sectional relationship. We provide practical guidelines, based on experience with scientific applications, for helping practitioners interpret their results and illustrate these ideas using data from a smoking cessation study.

Reducing Cost and Intravenous Duration of Nicardipine in Intracerebral Hemorrhage Patients via an Interdisciplinary Approach.

BACKGROUND: The mainstay of acute management of intracerebral hemorrhage (ICH) is blood pressure reduction. Intravenous (IV) nicardipine is an effective but costly intervention for blood pressure reduction in the intensive care unit (ICU). Earlier transition to oral (PO) antihypertensive agents may reduce ICU length of stay (LOS) and associated costs. We sought to study the effectiveness of an interdisciplinary intervention to start earlier transition to PO antihypertensives. METHODS: From July 2011 to July 2012, patients with ICH who received IV nicardipine were reviewed and screened for eligibility by an interdisciplinary team including physicians and pharmacists. These patients were compared to a control group 1 year prior to this intervention. The duration of nicardipine treatment (median hours), estimated costs, and ICU LOS were measured. RESULTS: A total of 35 patients and 44 controls were studied. The median hours of IV nicardipine use were significantly decreased from a baseline mean of 118 to 30 hours (P < .001); total cost savings per year was $433,566 ($18,475 per patient). The average LOS remained similar (8.4 versus 8.9 days, P < .990). In a follow-up study 1 year later, after the intervention was no longer used, a sample of 21 consecutive patients was reviewed and the duration of IV nicardipine treatment had increased to a mean of 96 hours. CONCLUSION: A physician and pharmacist-led project to initiate oral antihyperintensive medications earlier was successful in reducing the duration of IV nicardipine treatment in patients with ICH while leading to substantial cost savings.