Biomedical subjects

Jingjin Li

Publications and source records attributed to Jingjin Li.

8 recordsLinked to original sources

PubMed2006

The Indiana Chronic Disease Management Program.

The Indiana Chronic Disease Management Program (ICDMP) is intended to improve the quality and cost-effectiveness of care for Medicaid members with congestive heart failure (chronic heart failure), diabetes, asthma, and other conditions. The ICDMP is being assembled by Indiana Medicaid primarily from state and local resources and has seven components: (1) identification of eligible participants to create regional registries, (2) risk stratification of eligible participants, (3) nurse care management for high-risk participants, (4) telephonic intervention for all participants, (5) an Internet-based information system, (6) quality improvement collaboratives for primary care practices, and (7) program evaluation. The evaluation involves a randomized controlled trial in two inner-city group practices, as well as a statewide observational design. This article describes the ICDMP, highlights challenges, and discusses approaches to its evaluation.

Chronic Disease↗

PubMed2006

Factors associated with drug adherence and blood pressure control in patients with hypertension.

STUDY OBJECTIVES: To determine characteristics associated with drug adherence and blood pressure control among patients with hypertension, and to assess agreement between self-reported and refill adherences. DESIGN: Cross-sectional analysis of baseline data from an ongoing randomized controlled trial. SETTING: Primary care center at an urban, county health system in Indianapolis, Indiana. PATIENTS: Four hundred ninety-two participants with hypertension and taking at least one antihypertensive drug. MEASUREMENTS AND MAIN RESULTS: Social and demographic factors, comorbidity, self-reported drug adherence, prescription refill adherence, and systolic and diastolic blood pressures were recorded at baseline. Participants were aged 57 +/- 11 (mean +/- SD) years, were predominantly women (73%) and African-American (68%), and took 2.4 +/- 1.1 antihypertensive drugs. Agreement between self-reported and refill adherences was poor to fair (kappa = 0.21). On multiple logistic regression analysis, increased age (p< or =0.002) and being married (p=0.03) were independent predictors of improved self-reported and refill adherence, whereas depressed patients had low self-reported adherence (p=0.005), and African-Americans had low refill adherence (p<0.001). Compared with nonadherent patients, adherent patients had lower systolic (-5.4 mm Hg by self-report and -5.0 mm Hg by refill) and diastolic (-2.7 mm Hg by self-report and -3.0 mm Hg by refill) blood pressures (p< or =0.02). Increased age was the only other variable strongly associated with systolic and diastolic blood pressure control in both measures of drug adherence (p< or =0.001). The association of depression, race, and sex with blood pressure control was model dependent. CONCLUSION: Age, sex, race and depression are associated with antihypertensive drug adherence and blood pressure control. Self-reported and refill adherences appear to provide complementary information and are associated with reductions in systolic and diastolic blood pressure of similar magnitude.

Age Factors↗

PubMed2005

Association between adherence measurements of metoprolol and health care utilization in older patients with heart failure.

OBJECTIVE: Data from electronic dosing monitors and published pharmacokinetic parameters were used to derive medication adherence measures for immediate-release metoprolol and examine their association with health care utilization of outpatients aged 50 years or older with heart failure. METHODS: We used a 1-compartment model and published population pharmacokinetic parameters to estimate mean plasma metoprolol concentrations for patients treated for 6 to 12 months. In the absence of directly measured plasma concentrations, we calculated the intended mean plasma concentration (Cp'(ave)) under the assumption of perfect adherence to the prescribed dose and frequency of administration. Projected mean plasma concentrations (Cp(ave)) were estimated by use of data from recorded dosing times. In addition to taking adherence (percentage of dose taken) and scheduling adherence (percentage of doses taken on schedule), we calculated the deviation from the intended exposure (DeltaCp(ave) = Cp'(ave) - Cp(ave)) and the proportion of intended exposure achieved by the patient (Cp(ave) /Cp'(ave)). We assessed the association between the adherence measures and the numbers of emergency department visits and hospital admissions experienced by the patients. RESULTS: Patients (N = 80) were aged 62 +/- 8 years. Mean DeltaCp(ave) and Cp(ave)/Cp'(ave) were 7.9 ng/mL (SD, 10.7) and 0.6 (SD, 0.3), respectively. Log-linear models adjusted for patient functional status indicated that greater deviation from the intended metoprolol exposure (DeltaCp(ave)) was associated with increased numbers of emergency department visits ( P < .0001) and hospital admissions (P < .0001). A higher proportion of intended exposure (Cp(ave) /Cp'(ave)) corresponded to a reduced number of emergency department visits (P = .0204) and hospital admissions (P = .0093). Taking adherence was univariately associated with both emergency department visits and hospital visits (P < .0001 and P = .0010, respectively). Scheduling adherence was associated with the number of emergency department visits (P = .0181) but not with the number of hospital admissions (P = .1602). Model selection procedures consistently chose the proposed measures over taking adherence and scheduling adherence. CONCLUSION: Deviation from the intended exposure and proportion of intended exposure achieved by the patient are valid adherence measures for immediate-release metoprolol and are associated with health care utilization. The potential utility of these measures for other beta-adrenergic antagonists and perhaps other cardiovascular drugs should be investigated.

Aged↗

PubMed2005

Indiana chronic disease management program risk stratification analysis.

OBJECTIVE: The objective of this study was to compare the ability of risk stratification models derived from administrative data to classify groups of patients for enrollment in a tailored chronic disease management program. SUBJECTS: This study included 19,548 Medicaid patients with chronic heart failure or diabetes in the Indiana Medicaid data warehouse during 2001 and 2002. MEASURES: To predict costs (total claims paid) in FY 2002, we considered candidate predictor variables available in FY 2001, including patient characteristics, the number and type of prescription medications, laboratory tests, pharmacy charges, and utilization of primary, specialty, inpatient, emergency department, nursing home, and home health care. METHODS: We built prospective models to identify patients with different levels of expenditure. Model fit was assessed using R statistics, whereas discrimination was assessed using the weighted kappa statistic, predictive ratios, and the area under the receiver operating characteristic curve. RESULTS: We found a simple least-squares regression model in which logged total charges in FY 2002 were regressed on the log of total charges in FY 2001, the number of prescriptions filled in FY 2001, and the FY 2001 eligibility category, performed as well as more complex models. This simple 3-parameter model had an R of 0.30 and, in terms in classification efficiency, had a sensitivity of 0.57, a specificity of 0.90, an area under the receiver operator curve of 0.80, and a weighted kappa statistic of 0.51. CONCLUSION: This simple model based on readily available administrative data stratified Medicaid members according to predicted future utilization as well as more complicated models.

Adult↗

PubMed2004

Conditional mixed models adjusting for non-ignorable drop-out with administrative censoring in longitudinal studies.

In this paper, a class of conditional mixed models is proposed to adjust for non-ignorable drop-out, while also accommodating unequal follow-up due to staggered entry and administrative censoring in longitudinal studies. Conditional linear and quadratic models which model subject-specific slopes as linear or quadratic functions of the time-to-drop-out, as well as pattern mixture models are both special cases of this approach. We illustrate these models and compare them with the usual maximum likelihood approach assuming ignorable drop-out using data from a multi-centre randomized clinical trial of renal disease. Simulations under various scenarios where the drop-out mechanism is ignorable and non-ignorable are employed to evaluate the performance of these models.

Blood Pressure↗

PubMed2003

Statistical methods for chip calibration and saturation effects in antibody-spiked gene expression data.

Oligonucleotide microarrays are amongst, a set of technologies that allow for high throughput assessment of vast numbers of gene expressions. In order to evaluate gene expressions given detection limits, antibody spiking is often used providing one with an expression curve relating antibody treated expression and non-antibody treated expression. These curves can exhibit different functional shapes across chips and hence need to be standardized. In addition, each curve is subject to saturation effects, which are typically dealt with by extrapolating a linear fit to the subset of the data not visually subject to saturation. In this paper we introduce methods for the non-parametric standardization of expression curves using univariate smoothers. We also explore parametric methods for more efficient analysis of the standardized curves. We demonstrate an alternate method of parametric analysis using a weighted linear mixed effects model that does not arbitrarily delete data beyond an observed saturation point; allows for natural grouping of genes and provides significantly more accurate predictions than naive linear extrapolation. Both methodologies are studied through sets of simulations.

Antibodies↗

PubMed2002

A chronic inflammatory response dominates the skeletal muscle molecular signature in dystrophin-deficient mdx mice.

Mutations in dystrophin cause Duchenne muscular dystrophy (DMD), but absent dystrophin does not invariably cause necrosis in all muscles, life stages and species. Using DNA microarray, we established a molecular signature of dystrophinopathy in the mdx mouse, with evidence that secondary mechanisms are key contributors to pathogenesis. We used variability controls, adequate replicates and stringent analytic tools, including significance analysis of microarrays to estimate and manage false positive rates. In leg muscle, we identified 242 differentially expressed genes, >75% of which have not been previously reported as altered in human or animal dystrophies. Data provide evidence for coordinated activity of numerous components of a chronic inflammatory response, including cytokine and chemokine signaling, leukocyte adhesion and diapedesis, invasive cell type-specific markers, and complement system activation. Selective chemokine upregulation was confirmed by RT-PCR and immunoblot, and may be a key determinant of the nature of the inflammatory response in dystrophic muscle. Up-regulation of secreted phosphoprotein 1 (minopontin, osteopontin) mRNA and protein in dystrophic muscle identified a novel linkage between inflammatory cells and repair processes. Extracellular matrix genes were up-regulated in mdx to levels similar to those in DMD. Since, unlike DMD, mdx exhibits little fibrosis, data suggest that collagen regulation at post-transcriptional stages mediates extensive fibrosis in DMD. Taken together, these data identify a relatively neglected aspect of DMD, suggest new treatment avenues, and highlight the value of genome-wide profiling in study of complex disease processes.

Animals↗

PubMedDate not supplied

Telephonic case-finding of major depression in a Medicaid chronic disease management program for diabetes and heart failure.

OBJECTIVE: Major depression is common in low-income and chronically ill persons and is a barrier for effective chronic disease care. We evaluated a Medicaid-sponsored strategy for detecting depressive symptoms in adults with diabetes or congestive heart failure. METHODS: Using a two-item screening tool, 890 adults enrolled in the Indiana Chronic Disease Management Program were assessed by telephone for depressive symptoms between December 2003 and March 2004. A subset of 386 participants also completed the eight-item Patient Health Questionnaire (PHQ-8) depression measure. Antidepressant use was examined using pharmacy claims. RESULTS: Depressed mood or anhedonia was reported by 51% of participants. About one in four participants had a PHQ-8 score indicating a high risk for major depression (score >or=10). The two-item screen was 96% sensitive [95% confidence interval (CI), 89-99%] and 60% specific (95% CI, 54-65%) for identifying members at high risk for depression by the full PHQ-8 instrument. Only half of participants with high-risk PHQ-8 scores had a pharmacy claim indicating that an antidepressant medication was filled within 120 days of the depression screening. CONCLUSIONS: A two-stage, telephonic approach involving the PHQ-8 instrument for Medicaid members with either depressed mood or anhedonia could identify two clinically depressed persons for every nine members screened.

Antidepressive Agents↗