Thomas Ten Have

University of Pennsylvania, Filadelfia, Pennsylvania, United States

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Publications (177)811.43 Total impact

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    ABSTRACT: Copula-based approaches can be useful in multivariate modeling settings where multivariate dependency is of primary interest, such as estimating the reliability of selfreported sexual behavior assessed independently for male and female partners (dyad) in a couple-based HIV risk reduction study. Specifically, we investigate the reliability of couple reports using copulas, adjusting for key individual baseline covariates. We propose applying a copula modeling approach to measure the reliability of self-reported, shared sexual behaviors from couples where measures are assessed independently from male and female partners. In particular, we estimate measures of dependence, such as the odds ratios and binary correlations, using mixtures of max-infinitely divisible copulas with a bivariate logit model. This approach is flexible in measuring the effect of covariates on dependence parameters and for estimating marginal probabilities for multiple outcomes simultaneously. In this paper, we focus on estimating these two dependencies and explore the influences of additional covariate information on the copula parameter.We provide simulation results comparing copulabased estimates to moment estimates of the generalized estimating equation (GEE) for the correlation coefficients with respect to bias and 95% coverage probability. We illustrate that copulas have better performance in terms of bias, while their performance is similar with respect to efficiency. The estimator of the marginal probability using copula methods is robust to the choice of copula family. The choice of copula may affect the estimator of dependency when the dependency of the outcomes is very low. We apply these methods to data from the Multisite HIV/STD Prevention Trial for African American Couples (AAC) Study.
    No preview · Article · Jan 2016 · Statistics and its interface
  • Benjamin E Leiby · Thomas R Ten Have · Kevin G Lynch · Mary D Sammel
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    ABSTRACT: In many clinical studies, the disease of interest is multifaceted, and multiple outcomes are needed to adequately capture information about the characteristics of the disease or its severity. In the analysis of such diseases, it is often difficult to determine what constitutes improvement because of the multivariate nature of the outcome. Furthermore, when the disease of interest has an unknown etiology and/or is primarily a symptom-defined syndrome, there is potential for the disease population to have distinct subgroups. Identification of population subgroups is of interest as it may assist clinicians in providing appropriate treatment or in developing accurate prognoses. We propose multivariate growth curve latent class models that group subjects on the basis of multiple symptoms measured repeatedly over time. These groups or latent classes are defined by distinctive longitudinal profiles of a latent variable, which is used to summarize the multivariate outcomes at each point. The mean growth curve for the latent variable in each class defines the features of the class. We develop this model for any combination of continuous, binary, ordinal, or count outcomes within a Bayesian hierarchical framework. We use simulation studies to validate the estimation procedures. We apply our model to data from a randomized clinical trial evaluating the efficacy of Bacillus Calmette-Guerin in treating symptoms of interstitial cystitis where we are able to identify a class of subjects for whom treatment is effective. Copyright © 2012 John Wiley & Sons, Ltd.
    No preview · Article · Sep 2014 · Statistics in Medicine
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    ABSTRACT: Parkinson's disease (PD) significantly impacts both patients' and spouses' emotional and physical health. However, despite the importance of social relationships for wellbeing, few studies have examined relationship quality and their correlates in individuals with PD and their partners. Specifically, no known studies have examined the association between benefit finding, or the experience of personal growth and other positive changes in the face of a stressor, and perceived marital quality. To address these gaps in the field, 25 married couples participated in a cross-sectional, pilot study. Patients were veterans diagnosed with idiopathic PD receiving care at the Philadelphia VA Medical Center. Each patient and spouse independently completed self-reported measures of sociodemographics, physical and mental wellbeing, caregiver burden, marital quality, and perceived benefits associated with having PD. Actor-partner interdependence models revealed that, after adjusting for covariates, greater perceived benefits from either having PD or living with a spouse with PD was associated with greater marital quality, both for that individual and their partner. Thus, perceiving positive consequences, such as personal growth, as a result of personally having PD or living with a spouse with PD is related to greater marital quality for both members of the marital dyad. Findings may inform individual and couples-based interventions that address the value of benefit finding and incorporate other techniques of positive reappraisal. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
    No preview · Article · Sep 2014 · Journal of Family Psychology
  • Zvi D. Gellis · Bonnie L. Kenaley · Thomas Ten Have
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    ABSTRACT: Objectives To evaluate an integrated telehealth intervention (Integrated Telehealth Education and Activation of Mood (I-TEAM)) to improve chronic illness (congestive heart failure, chronic obstructive pulmonary disease) and comorbid depression in the home healthcare setting.DesignRandomized controlled trial.SettingHospital-affiliated home healthcare setting.ParticipantsMedically frail older homebound individuals (N = 102).InterventionThe 3-month intervention consisted of integrated telehealth chronic illness and depression care, with a telehealth nurse conducting daily telemonitoring of symptoms, body weight, and medication use; providing eight weekly sessions of problem-solving treatment for depression; and providing for communication with participants' primary care physicians, who also prescribed antidepressants. Control participants were allocated to usual care with in-home nursing plus psychoeducation (UC+P).MeasurementsThe two groups were compared at baseline and 3 and 6 months after baseline on clinical measures (depression, health, problem-solving) and 12 months after baseline on health utilization (readmission, episodes of care, and emergency department (ED) visits).ResultsDepression scores were 50% lower in the I-TEAM group than in the UC+P group at 3 and 6 months. Those who received the I-TEAM intervention significantly improved their problem-solving skills and self-efficacy in managing their medical condition. The I-TEAM group had significantly fewer ED visits (P = .01) but did not have significantly fewer days in the hospital at 12 months after baseline.Conclusion Integrated telehealth care for older adults with chronic illness and comorbid depression can reduce symptoms and postdischarge ED use in home health settings.
    No preview · Article · Mar 2014 · Journal of the American Geriatrics Society
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    ABSTRACT: Abstract Background: Asthmatic adults from low-income urban neighborhoods have inferior health outcomes which in part may be due to barriers accessing care and with patient-provider communication. We adapted a patient advocate (PA) intervention to overcome these barriers. Objective: To conduct a pilot study to assess feasibility, acceptability, and preliminary evidence of effectiveness. Methods: A prospective randomized design was employed with mixed methods evaluation. Adults with moderate or severe asthma were randomized to 16 weeks of PA or a minimal intervention (MI) comparison condition. The PA, a nonprofessional, modeled preparations for a medical visit, attended the visit, and confirmed understanding. The PA facilitated scheduling, obtaining insurance coverage, and overcoming barriers to implementing medical advice. Outcomes included electronically-monitored inhaled corticosteroid adherence, asthma control, quality of life, FEV1, ED visits, and hospitalizations. Mixed-effects models guided an intention-to-treat analysis. Results: 100 adults participated: age 47+14 years, 75% female, 71% African American, 16% white, baseline FEV1 69% + 18%, 36% experiencing hospitalizations and 56% ED visits for asthma in the prior year. Ninety-three subjects completed all visits; 36 of 53 PA-assigned had a PA visit. Adherence declined significantly in the control (p= 0.001) but not significantly in the PA group (p=.30). Both PA and MI groups demonstrated improved asthma control (p=0.01 in both) and quality of life (p=0.001, p=0.004). Hospitalizations and ED visits for asthma did not differ between groups. The observed changes over time tended to favor the PA group, but this study was underpowered to detect differences between groups. Conclusion: The PA intervention was feasible and acceptable and demonstrated potential for improving asthma control and quality of life.
    Full-text · Article · Jun 2013 · Journal of Asthma
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    ABSTRACT: Radical cystectomy (RC) is the standard treatment for muscle-invasive urothelial carcinoma of the bladder. Trimodality bladder-preserving therapy (BPT) is an alternative to RC, but randomized comparisons of RC versus BPT have proven infeasible. To compare RC versus BPT, we undertook an observational cohort study using registry and administrative claims data from the Surveillance, Epidemiology and End Results-Medicare database. We identified patients age 65 years or older diagnosed between 1995 and 2005 who received RC (n = 1426) or BPT (n = 417). We examined confounding and stage misclassification in the comparison of RC and BPT by using multivariable adjustment, propensity score-based adjustment, instrumental variable (IV) analysis, and simulations. Patients who received BPT were older and more likely to have comorbid disease. After propensity score adjustment, BPT was associated with an increased hazard of death from any cause (hazard ratio [HR] 1.26; 95% confidence interval [CI] 1.05-1.53) and from bladder cancer (HR 1.31; 95% CI 0.97-1.77). Using the local area cystectomy rate as an instrument, IV analysis demonstrated no differences in survival between BPT and RC (death from any cause HR 1.06; 95% CI 0.78-1.31; death from bladder cancer HR 0.94; 95% CI 0.55-1.18). Simulation studies for stage misclassification yielded results consistent with the IV analysis. Survival estimates in an observational cohort of patients who underwent RC versus BPT differ by analytic method. Multivariable and propensity score adjustment revealed greater mortality associated with BPT relative to RC, while IV analysis and simulation studies suggest that the two treatments are associated with similar survival outcomes.
    Preview · Article · Jun 2013 · Value in Health
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    ABSTRACT: BACKGROUND: Low health literacy is associated with poor outcomes in asthma and other diseases, but the mechanisms governing this relationship are not well defined. OBJECTIVE: We sought to assess whether literacy is related to subsequent asthma self-management, measured as adherence to inhaled steroids, and asthma outcomes. METHODS: In a prospective longitudinal cohort study, numeric (Asthma Numeracy Questionnaire) and print literacy (Short Test of Functional Health Literacy in Adults) were assessed at baseline in adults with moderate or severe asthma for their impact on subsequent electronically monitored adherence and asthma outcomes (asthma control, asthma-related quality of life, and FEV1) over 26 weeks, using mixed-effects linear regression models. RESULTS: A total of 284 adults participated: age, 48 ± 14 years, 71% females, 70% African American, 6% Latino, mean FEV1 66% ± 19%, 86 (30%) with hospitalizations, and 148 (52%) with emergency department visits for asthma in the prior year. Mean Asthma Numeracy Questionnaire score was 2.3 ± 1.2 (range, 0-4); mean Short Test of Functional Health Literacy in Adults score was 31 ± 8 (range, 0-36). In unadjusted analyses, numeric and print literacy were associated with better adherence (P = .01 and P = .08, respectively), asthma control (P = .005 and P < .001, respectively), and quality of life (P < .001 and P < .001, respectively). After controlling for age, sex, and race/ethnicity, the associations diminished and only quality of life (numeric P = .03, print P = .006) and asthma control (print P = .005) remained significantly associated with literacy. Race/ethnicity, income, and educational attainment were correlated (P < .001). CONCLUSION: While the relationship between literacy and health is complex, interventions that account for and address the literacy needs of patients may improve asthma outcomes.
    No preview · Article · Apr 2013 · The Journal of allergy and clinical immunology
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    ABSTRACT: Background: Economic disadvantage is associated with depression and suicide. We sought to determine whether economic disadvantage reduces the effectiveness of depression treatments received in primary care. Methods: We conducted differential-effects analyses of the Prevention of Suicide in Primary Care Elderly: Collaborative Trial, a primary-care-based randomized, controlled trial for late-life depression and suicidal ideation conducted between 1999 and 2001, which included 514 patients with major depression or clinically significant minor depression. Results: The intervention effect, defined as change in depressive symptoms from baseline, was stronger among persons reporting financial strain at baseline (differential effect size = -4.5 Hamilton Depression Rating Scale points across the study period [95% confidence interval = -8.6 to -0.3]). We found similar evidence for effect modification by neighborhood poverty, although the intervention effect weakened after the initial 4 months of the trial for participants residing in poor neighborhoods. There was no evidence of substantial differences in the effectiveness of the intervention on suicidal ideation and depression remission by economic disadvantage. Conclusions: Economic conditions moderated the effectiveness of primary-care-based treatment for late-life depression. Financially strained individuals benefited more from the intervention; we speculate this was because of the enhanced treatment management protocol, which led to a greater improvement in the care received by these persons. People living in poor neighborhoods experienced only temporary benefit from the intervention. Thus, multiple aspects of economic disadvantage affect depression treatment outcomes; additional work is needed to understand the underlying mechanisms.
    No preview · Article · Jan 2013 · Epidemiology (Cambridge, Mass.)
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    ABSTRACT: Purpose: Depression and suicide are major public health concerns, and are often unrecognized among the elderly. This study investigated social inequalities in depressive symptoms and suicidal ideation among older adults. Methods: Data come from 1,226 participants in PROSPECT (Prevention of Suicide in Primary Care Elderly: Collaborative Trial), a large primary care-based intervention trial for late-life depression. Linear and logistic regressions were used to analyze depressive symptoms and suicidal ideation over the 2-year follow-up period. Results: Mean Hamilton Depression Rating Scale (HDRS) scores were significantly higher among participants in financial strain [regression coefficient (b) = 1.78, 95 % confidence interval (CI) = 0.67-2.89] and with annual incomes below $20,000 (b = 1.67, CI = 0.34-3.00). Financial strain was also associated with a higher risk of suicidal ideation (odds ratio = 2.35, CI = 1.38-3.98). Conclusions: There exist marked social inequalities in depressive symptoms and suicidal ideation among older adults attending primary care practices, the setting in which depression is most commonly treated. Our results justify continued efforts to understand the mechanisms generating such inequalities and to recognize and provide effective treatments for depression among high-risk populations.
    No preview · Article · Sep 2012 · Social Psychiatry
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    ABSTRACT: BACKGROUND:: For patients recovering from severe acute illness, admission to a long-term acute care hospital (LTAC) is an increasingly common alternative to continued management in an intensive care unit (ICU). OBJECTIVE:: To examine the effectiveness of LTAC transfer in patients with chronic critical illness. RESEARCH DESIGN:: Retrospective cohort study in United States hospitals from 2002 to 2006. SUBJECTS:: Medicare beneficiaries with chronic critical illness, defined as mechanical ventilation and at least 14 days of intensive care. MEASURES:: Survival, costs, and hospital readmissions. We used multivariate analyses and instrumental variables to account for differences in patient characteristics, the timing of LTAC transfer, and selection bias. RESULTS:: A total of 234,799 patients met our definition of chronic critical illness. Of these, 48,416 (20.6%) were transferred to an LTAC. In the instrumental variable analysis, patients transferred to an LTAC experienced similar survival compared with patients who remained in an ICU [adjusted hazard ratio=0.99; 95% confidence interval (CI), 0.96 to 1.01; P=0.27). Total hospital-related costs in the 180 days after admission were lower among patients transferred to LTACs (adjusted cost difference=-$13,422; 95% CI, -26,662 to -223, P=0.046). This difference was attributable to a reduction in skilled nursing facility admissions (adjusted admission rate difference=-0.591; 95% CI, -0.728 to -0.454; P<0.001). Total Medicare payments were higher (adjusted cost difference=$15,592; 95% CI, 6343 to 24,842; P=0.001). CONCLUSIONS:: Patients with chronic critical illness transferred to LTACs experience similar survival compared with patients who remain in ICUs, incur fewer health care costs driven by a reduction in postacute care utilization, however, invoke higher overall Medicare payments.
    No preview · Article · Aug 2012 · Medical care
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    Mikhail Traskin · Wei Wang · Thomas R Ten Have · Dylan S Small
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    ABSTRACT: The PAF for an exposure is the fraction of disease cases in a population that can be attributed to that exposure. One method of estimating the PAF involves estimating the probability of having the disease given the exposure and confounding variables. In many settings, the exposure will interact with the confounders and the confounders will interact with each other. Also, in many settings, the probability of having the disease is thought, based on subject matter knowledge, to be a monotone increasing function of the exposure and possibly of some of the confounders. We develop an efficient approach for estimating logistic regression models with interactions and monotonicity constraints, and apply this approach to estimating the population attributable fraction (PAF). Our approach produces substantially more accurate estimates of the PAF in some settings than the usual approach which uses logistic regression without monotonicity constraints.
    Preview · Article · Jun 2012 · Biostatistics
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    Bing Cai · Sean Hennessy · James H Flory · Daohang Sha · Thomas R Ten Have · Dylan S Small
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    ABSTRACT: We studied the application of the generalized structural mean model (GSMM) of instrumental variable (IV) methods in estimating treatment odds ratios (ORs) for binary outcomes in pharmacoepidemiologic studies and evaluated the bias of GSMM compared to other IV methods. Because of the bias of standard IV methods, including two-stage predictor substitution (2SPS) and two-stage residual inclusion (2SRI) with binary outcomes, we implemented another IV approach based on the GSMM of Vansteelandt and Goetghebeur. We performed simulations under the principal stratification setting and evaluated whether GSMM provides approximately unbiased estimates of the causal OR and compared its bias and mean squared error to that of 2SPS and 2SRI. We then applied different IV methods to a study comparing bezafibrate versus other fibrates on the risk of diabetes. Our simulations showed that unlike the standard logistic, 2SPS, and 2SRI procedures, our implementation of GSMM provides an approximately unbiased estimate of the causal OR even under unmeasured confounding. However, for the effect of bezafibrate versus other fibrates on the risk of diabetes, the GSMM and two-stage approaches yielded similarly attenuated and statistically non-significant OR estimates. The attenuation of the OR by the two-stage and GSMM IV approaches suggests unmeasured confounding, although violations of the IV assumptions or differences in the parameters estimated could be playing a role. The GSMM IV approach provides approximately unbiased adjustment for unmeasured confounding on binary outcomes when a valid IV is available.
    Full-text · Article · May 2012 · Pharmacoepidemiology and Drug Safety
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    Jessica M Fishman · Thomas Ten Have · David Casarett
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    ABSTRACT: Because cancers are a leading cause of death, these diseases receive a great deal of news attention. However, because news media frequently target specific racial or ethnic audiences, some populations may receive different information, and it is unknown whether reporting equally informs all audiences about the options for care at the end of life. This study of news reporting compared "mainstream" (general market) media with African American media, which serves the largest minority group. The specific goal of this study was to determine whether these news media communicate differently about cure-directed cancer treatment and end-of-life alternatives. This content analysis included 660 cancer news stories from online and print media that targeted either African American or mainstream audiences. The main outcome measures included whether reporting discussed adverse events of cancer treatment, cancer treatment failure, cancer death/dying, and end-of-life palliative or hospice care. Unadjusted and adjusted analyses indicated that the news stories in the African American media are less likely than those in mainstream media to discuss each of the topics studied. Comparing the proportions of news stories in mainstream versus African American media, 31.6% versus 13.6% discussed adverse events (odds ratio [OR], 2.92; 95% confidence interval [CI], 1.51-5.66; P = .001); 14.1% versus 4.2% mentioned treatment failure (OR, 3.79; 95% CI, 1.45-9.88; P = .006); and 11.9% versus 3.8% focused on death/dying (OR, 3.42; 95% CI, 1.39-8.38; P = .007). Finally, although very few news stories discussed end-of-life hospice or palliative care, all were found in mainstream media (7/396 vs 0/264). The African American news media sampled are less likely than mainstream news media to portray negative cancer outcomes and end-of-life care. Given media's segmented audiences, these findings raise concerns that not all audiences are being informed equally well. Because media content is modifiable, there may be opportunities to improve public cancer communication.
    Full-text · Article · Apr 2012 · Cancer
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    ABSTRACT:  Telehealth care is emerging as a viable intervention model to treat complex chronic conditions, such as heart failure (HF) and chronic obstructive pulmonary disease (COPD), and to engage older adults in self-care disease management.   We report on a randomized controlled trial examining the impact of a multifaceted telehealth intervention on health, mental health, and service utilization outcomes among homebound medically ill older adults diagnosed with HF or COPD. Random effects regression modeling was used, and we hypothesized that older adults in the telehealth intervention (n = 51) would receive significantly better quality of care resulting in improved scores in health-related quality of life, mental health, and satisfaction with care at 3 months follow-up as compared with controls (n = 51) and service utilization outcomes at 12 months follow-up.   At follow-up, the telehealth intervention group reported greater increases in general health and social functioning, and improved in depression symptom scores as compared with usual care plus education group. The control group had significantly more visits to the emergency department than the telehealth group. There was an observed trend toward fewer hospital days for telehealth participants, but it did not reach significance at 12 months.   Telehealth may be an efficient and effective method of systematically delivering integrated care in the home health sector. The use of telehealth technology may benefit homebound older adults who have difficulty accessing care due to disability, transportation, or isolation.
    Full-text · Article · Jan 2012 · The Gerontologist
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    ABSTRACT: To investigate cigarette smoking in cutaneous lupus erythematosus (CLE). Prospective longitudinal cohort study. Urban cutaneous autoimmune disease clinic. A total of 218 individuals with CLE or systemic lupus erythematosus and lupus nonspecific skin disease seen between January 5, 2007, and July 30, 2010. Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) scores to assess disease severity and response to treatment and Skindex 29+3 scores to assess patient quality of life. Current smokers with lupus erythematosus had higher median CLASI scores (9.5) than did never (7.0) and past (6.0) smokers with CLE (P = .02). Current smokers had higher median scores on all the Skindex 29+3 subsets. Current smokers taking hydroxychloroquine sulfate had higher quinacrine hydrochloride use than did nonsmokers (P = .04). Two to 7 months after enrollment, current smokers (median CLASI change, -3) treated with only antimalarial agents improved more than never (1) and past (0) smokers (P = .02). Eight months or more after enrollment, current smokers (CLASI change, 3.5) treated with antimalarial drugs plus at least 1 additional immunomodulator improved less than never (-1.5) and past (0) smokers (P = .04). Current smokers with lupus erythematosus had worse disease, had worse quality of life, and were more often treated with a combination of hydroxychloroquine and quinacrine than were nonsmokers. Never and past smokers showed greater improvement when treated with antimalarial agents plus at least 1 additional immunomodulator. Current smokers had greater improvement when treated with antimalarial drugs only.
    Full-text · Article · Nov 2011 · Archives of dermatology
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    ABSTRACT: Greening of vacant urban land may affect health and safety. The authors conducted a decade-long difference-in-differences analysis of the impact of a vacant lot greening program in Philadelphia, Pennsylvania, on health and safety outcomes. "Before" and "after" outcome differences among treated vacant lots were compared with matched groups of control vacant lots that were eligible but did not receive treatment. Control lots from 2 eligibility pools were randomly selected and matched to treated lots at a 3:1 ratio by city section. Random-effects regression models were fitted, along with alternative models and robustness checks. Across 4 sections of Philadelphia, 4,436 vacant lots totaling over 7.8 million square feet (about 725,000 m(2)) were greened from 1999 to 2008. Regression-adjusted estimates showed that vacant lot greening was associated with consistent reductions in gun assaults across all 4 sections of the city (P < 0.001) and consistent reductions in vandalism in 1 section of the city (P < 0.001). Regression-adjusted estimates also showed that vacant lot greening was associated with residents' reporting less stress and more exercise in select sections of the city (P < 0.01). Once greened, vacant lots may reduce certain crimes and promote some aspects of health. Limitations of the current study are discussed. Community-based trials are warranted to further test these findings.
    Full-text · Article · Nov 2011 · American journal of epidemiology
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    ABSTRACT: The heightened risk of persons with serious mental illness to contract and transmit HIV is recognized as a public health problem. Persons with HIV and mental illness may be at risk for poor treatment adherence, development of treatment-resistant virus, and worse outcomes. The objective of this study was to test the effectiveness of a community-based advanced practice nurse (APN) intervention (PATH, Preventing AIDS Through Health) to promote adherence to HIV and psychiatric treatment regimens. Community-dwelling HIV-positive participants with co-occurring serious mental illnesses (N=238) were recruited from community HIV provider agencies from 2004 to 2008 to participate in the randomized controlled trial. Participants in the intervention group (N=128) were assigned an APN who provided community-based care management at a minimum of one visit per week and coordinated clients' medical and mental health care for one year. Viral load and CD4 cell count were evaluated at baseline and 12 months. Longitudinal models for continuous log viral load showed that compared with the control group, the intervention group exhibited a significantly greater reduction in log viral load at 12 months (d=-.361 log 10 copies per milliliter, p<.001). Differences in CD4 counts from baseline to 12 months were not statistically significant. This project demonstrated the effectiveness of community-based APNs in delivering a tailored intervention to improve outcomes of individuals with HIV and co-occurring serious mental illnesses. Persons with these co-occurring conditions can be successfully treated; with appropriate supportive services, their viral loads can be reduced.
    Full-text · Article · Nov 2011 · Psychiatric services (Washington, D.C.)

  • No preview · Article · Oct 2011 · Fuel and Energy Abstracts
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    ABSTRACT: A case-control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed.
    Full-text · Article · Sep 2011 · Substance Use & Misuse
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    Bing Cai · Dylan S Small · Thomas R Ten Have
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    ABSTRACT: We present closed-form expressions of asymptotic bias for the causal odds ratio from two estimation approaches of instrumental variable logistic regression: (i) the two-stage predictor substitution (2SPS) method and (ii) the two-stage residual inclusion (2SRI) approach. Under the 2SPS approach, the first stage model yields the predicted value of treatment as a function of an instrument and covariates, and in the second stage model for the outcome, this predicted value replaces the observed value of treatment as a covariate. Under the 2SRI approach, the first stage is the same, but the residual term of the first stage regression is included in the second stage regression, retaining the observed treatment as a covariate. Our bias assessment is for a different context from that of Terza (J. Health Econ. 2008; 27(3):531-543), who focused on the causal odds ratio conditional on the unmeasured confounder, whereas we focus on the causal odds ratio among compliers under the principal stratification framework. Our closed-form bias results show that the 2SPS logistic regression generates asymptotically biased estimates of this causal odds ratio when there is no unmeasured confounding and that this bias increases with increasing unmeasured confounding. The 2SRI logistic regression is asymptotically unbiased when there is no unmeasured confounding, but when there is unmeasured confounding, there is bias and it increases with increasing unmeasured confounding. The closed-form bias results provide guidance for using these IV logistic regression methods. Our simulation results are consistent with our closed-form analytic results under different combinations of parameter settings.
    Full-text · Article · Jul 2011 · Statistics in Medicine

Publication Stats

7k Citations
811.43 Total Impact Points


  • 1999-2016
    • University of Pennsylvania
      • • Center for Clinical Epidemiology and Biostatistics
      • • Department of Biostatistics and Epidemiology
      • • Department of Psychology
      • • Department of Medicine
      Filadelfia, Pennsylvania, United States
  • 2004-2014
    • William Penn University
      Filadelfia, Pennsylvania, United States
  • 2013
    • University of Connecticut
      Сторс, Connecticut, United States
  • 2011
    • Hospital of the University of Pennsylvania
      Filadelfia, Pennsylvania, United States
  • 2009
    • Weill Cornell Medical College
      • Department of Psychiatry
      New York, New York, United States
  • 2003-2008
    • The Children's Hospital of Philadelphia
      • Department of Child and Adolescent Psychiatry
      Filadelfia, Pennsylvania, United States
  • 1988-2008
    • University of Michigan
      • • Institute for Social Research
      • • Department of Biostatistics
      Ann Arbor, Michigan, United States
  • 2001
    • Universidad Autónoma de Madrid
      • Psychiatry
      Madrid, Madrid, Spain
  • 2000
    • Wake Forest School of Medicine
      • Division of Public Health Sciences
      Winston-Salem, North Carolina, United States
  • 1994-1999
    • Pennsylvania State University
      • • Department of Psychiatry
      • • Department of Radiology
      University Park, Maryland, United States
  • 1996
    • Penn State Hershey Medical Center and Penn State College of Medicine
      Hershey, Pennsylvania, United States
  • 1992-1994
    • Baylor College of Dentistry
      • Department of Oral and Maxillofacial Surgery
      Dallas, Texas, United States