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Biomedical subjects

C Daniel Mullins

Publications and source records attributed to C Daniel Mullins.

At least 19 recordsLinked to original sources
PubMed2007

Center effects in anemia management of dialysis patients.

This study set out to determine whether there is a center effect on anemia management in hemodialysis patients. The US Renal Data System and Medicare standard analysis files were analyzed. Between-center variation and within-facility correlations in hematocrit values were examined in two separate data sets (years 2000 and 2001) and compared with simulated samples that were composed of random values that assumed no center effect. Mixed-effect models were used to adjust for multiple factors and quantify the within-facility correlation in hematocrit values. Expected hematocrit values were compared in patients who underwent dialysis at poor and superior performing facilities with fixed characteristics including epoetin alpha dosing. There was a wider center variation in hematocrit for the actual versus simulated data and a coefficient of variation of 4.1% for the former versus 1.7% for the latter, in both years. The within-facility correlation for hematocrit was 0.053 (95% confidence interval 0.050 to 0.056; P < 0.001) in 2000 with similar values in 2001 but no within-facility correlation in the simulated data. The impact of these findings was demonstrated with a difference in expected hematocrit for a patient who was treated with fixed-dosage epoetin alpha in the poorest versus best performing units (mean difference in expected hematocrit 3.06; 95% confidence interval 3.03 to 3.09; P < 0.001). Key attributes of a center effect on anemia management in hemodialysis have been identified. The presence of a center effect suggests that there are facility-specific processes that influence performance in dialysis anemia management and are independent of commonly titrated inputs, such as dosing of erythropoietic agents.

Anemia↗
PubMed2006

Effect of initial ziprasidone dose on treatment persistence in schizophrenia.

OBJECTIVE: To determine the relationship between ziprasidone initial dose and treatment persistence among patients diagnosed with schizophrenia. METHOD: Adult Medicaid recipients (N=1096) diagnosed with schizophrenia who had ziprasidone prescription claims between July 1, 2001 and September 30, 2003, were categorized by initial dose: low (20-60 mg per day, n=464), medium (61-119 mg per day, n=320) and high dose (120-160 mg per day, n=312). Treatment persistence up to 365 days was measured using refill patterns, allowing 15-day gaps between expected refill dates. Multivariate survival analysis explored the simultaneous impact of age, gender, race, previous hospitalization, and concomitant medication usage, in addition to initial dose of ziprasidone. Sensitivity analysis tested the robustness of results with different definitions for persistence and allowable gaps between refills. RESULTS: Discontinuation rates across the observation period (maximum, 12 months per individual) were lower for patients initiated with high-dose than low-dose ziprasidone (P=0.001). Other factors significantly associated with greater discontinuation of medication were monotherapy (versus combination therapy) and hospitalization within the 6 months prior to the index date of therapy. Black race was associated with greater discontinuation, although this was not consistent across sensitivity analyses. CONCLUSIONS: Patients with schizophrenia started on high doses of ziprasidone have lower discontinuation rates in a retrospective Medicaid database than patients started on low doses. These results were robust across various sensitivity analyses.

Adult↗
PubMed2006

Recruitment and participation in clinical trials: socio-demographic, rural/urban, and health care access predictors.

BACKGROUND: Recruitment and participation in clinical trials by minorities, particularly African Americans and rural underserved populations, are low. This report examines predictors of clinical trial recruitment and participation for adult Marylanders. METHODS: A cross-sectional design was used to survey 5154 adults (18 years and older) residing in 13 of the 24 jurisdictions in Maryland, including urban Baltimore City, and the rural regions of Western Maryland and the Eastern Shore. The survey, conducted between December 2001 and March 2003, used Computer-Assisted Telephone Interviewing and random-digit dialing procedures. Primary dependent variables included "ever asked to participate" (i.e., recruited) and "participated" in clinical trials. RESULTS: 11.1% of the respondents had been recruited to clinical trials. In addition, 59.4% of the respondents recruited to clinical trials actually participated in a clinical trial. Among respondents recruited to clinical trials, black and middle income respondents were significantly less likely to actually participate in clinical trials; whereas, respondents who received information about clinical trials from their health care provider, who were knowledgeable about clinical trials, and those who had the time commitment were significantly more likely to participate in clinical trials. CONCLUSIONS: These results suggest serious gaps in efforts to recruit racial/ethnic minorities and residents of rural regions into clinical trials. The findings provide the basis for the development and implementation of community-based educational programs for both the general public and health care professionals, and to enhance availability of community-based clinical trials, especially in the rural areas of the state.

Adult↗
PubMed2006

Comparison of first refill rates among users of sertraline, paroxetine, and citalopram.

BACKGROUND: Research suggests high rates of discontinuation of selective serotonin reuptake inhibitors (SSRIs). OBJECTIVE: The aim of this study was to compare the rates of first refill for sertraline, paroxetine, and citalopram, the 3 most commonly used SSRIs that were under patent protection at the time of the study. SSRIs that were available in generic formulations in this period were not included in the analysis because prescribing patterns and compliance rates for generic products may differ from those of branded products. METHODS: This analysis was conducted using claims data from an administrative database. Claims from January 1, 1999, through June 30, 2002, were analyzed. Adults aged 18 to 64 years with a diagnosis of depression, posttraumatic stress disorder, or social anxiety disorder who had initiated one of the SSRIs of interest during this period were included in the analysis. Refill status was determined based on a refill of the SSRI prescription within 1.5 times the days' supply dispensed or 15 days after the dispensing date of the index SSRI. To adjust for the effects of confounding factors, we conducted a multivariate logistic regression on the status of the first refill. The covariates included age (continuous variable), sex, index drugs (with sertraline as the reference group), and a dummy variable for copayment >15 dollars. RESULTS: Recipients of sertraline (n=5590) or citalopram (n=4124) were more likely than recipients of paroxetine (n=5201) to refill their original prescriptions (refill rate, 54.70%, 54.49%, and 50.99%, respectively; both comparisons, P<0.001). In the logistic regression, the effects of age, sex, and copayment were not significant. CONCLUSIONS: This study found that the likelihood of refilling the first prescription varied by SSRI. In the population studied, patients were significantly more likely to refill the first prescription for sertraline or citalopram than the first prescription for paroxetine.

Adolescent↗
PubMed2006

Cost-effectiveness analysis of linezolid compared with vancomycin for the treatment of nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus.

OBJECTIVE: This study compared the cost-effectiveness of linezolid and vancomycin in the treatment of patients with nosocomial pneumonia (NP) caused by methicillin-resistant Staphylococcus aureus (MRSA). METHODS: A retrospective decision-analytic model was applied to pooled data from 2 prospective, randomized, controlled, double-blind studies, and claims data from a large health plan (3.3 million members) located in the Mid-Atlantic region. Using hospital claims for patients in the health plan with suspected NP, we then determined their daily billed (submitted) hospital charges for 4 mutually exclusive potential health outcomes of linezolid or vancomycin treatment: survival with bacteremia, survival without bacteremia, nonsurvival with bacteremia, and nonsurvival without bacteremia. To generate the expected total daily billed hospital charge for each drug-treatment group, we weighted the determined daily billed hospital charges by the probabilities of each outcome developing in each treatment arm, as derived from the clinical-trial data. Drug acquisition costs were then incorporated, and the difference in expected total costs relative to the difference in rates of survival between the linezolid and vancomycin arms was used to calculate the incremental cost-effectiveness ratio (ICER) for linezolid. RESULTS: Costs were higher for nonsurviving patients compared with surviving patients. Estimated median daily billed treatment charges were $2888 for linezolid and $2993 for vancomycin. Based on Monte Carlo simulations, the respective 95% CIs were $2671 to $3106 and $2615 to $3372. Using mean treatment durations of 11.3 and 10.7 days, respectively, we obtained expected total hospitalization charges of $32,636 for linezolid treatment (95% CI, $30,182-$35,098), compared with $32,024 for vancomycin treatment (95% CI, $27,978-$36,078). The ICER for linezolid per life saved was $3600. CONCLUSIONS: The higher acquisition cost of linezolid was almost completely offset by improved survival and a reduction in health care costs associated with improved survival. As a result, linezolid was almost cost-neutral compared with vancomycin in the treatment of NP caused by MRSA.

Acetamides↗
PubMed2006

Disparities in access to essential new prescription drugs between non-Hispanic whites, non-Hispanic blacks, and Hispanic whites.

Prior studies do not address racial and ethnic disparities in essential new drug use and whether disparities decrease through time. Using the Medical Expenditure Panel Survey (1996-2001), racial and ethnic disparities were examined separately by comparing non-Hispanic whites to non-Hispanic blacks and Hispanic whites, respectively. New drugs were defined as approved within the past 5 years, and an expert panel identified essential drugs. Negative binomial models adjusted for socioeconomic and health characteristics. The mean annual number of times essential new drugs were obtained among non-Hispanic whites, non-Hispanic blacks, and Hispanic whites were 1.02, 0.94, and 0.70, respectively. After adjusting for confounders, ethnic disparities generally were not significant, but racial disparities became significant. This study did not identify declining disparities during early years of drugs' life cycles. Disparities exist in new, essential drug acquisition between non-Hispanic whites and non-Hispanic blacks. Socioeconomic and health characteristics explain many of the observed disparities.

Adolescent↗
PubMed2006

Cost-of-illness studies : a review of current methods.

The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods are a major driver of variation in COI estimates. The objective of this review was to document the variation in the methodologies employed in COI studies and to highlight the benefits and limitations of these methods. The review of COI studies was implemented following a four-step procedure: (i) a structured literature search of MEDLINE, JSTOR and EconLit; (ii) a review of abstracts using pre-defined inclusion and exclusion criteria; (iii) a full-text review using pre-defined inclusion and exclusion criteria; and (iv) classification of articles according to the methods used to calculate costs. This review identified four COI estimation methods (Sum_All Medical, Sum_Diagnosis Specific, Matched Control and Regression) that were used in categorising articles. Also, six components of direct medical costs and five components of indirect/non-medical costs were identified and used in categorising articles.365 full-length articles were reflected in the current review following the structured literature search. The top five cost components were emergency room/inpatient hospital costs, outpatient physician costs, drug costs, productivity losses and laboratory costs. The dominant method, Sum_Diagnosis Specific, was a total costing approach that restricted the summation of medical expenditures to those related to a diagnosis of the disease of interest. There was considerable variation in the methods used within disease subcategories. In several disease subcategories (e.g. asthma, dementia, diabetes mellitus), all four estimation methods were represented, and in other cases (e.g. HIV/AIDS, obesity, stroke, urinary incontinence, schizophrenia), three of the four estimation methods were represented. There was also evidence to suggest that the strengths and weaknesses of each method were considered when applying a method to a specific illness. Comparisons and assessments of COI estimates should consider the method used to estimate costs both as an important source of variation in the reported COI estimates and as a marker of the reliability of the COI estimate.

Ambulatory Care↗
PubMed2006

Drug therapy persistence and stroke recurrence.

OBJECTIVE: To assess the effect of persistence of use of warfarin sodium, aspirin, or clopidogrel bisulfate on stroke recurrence in a Medicaid high-risk, largely female, African American population. STUDY DESIGN: Prospective non-concurrent cohort, longitudinal data analysis of medical and pharmacy claims of stroke patients from Medicaid managed care organizations between January 1, 2001, and December 31, 2003. METHODS: Cox proportional hazards models were used to predict the likelihood of avoiding a recurrence as a function of persistence of use of the initial medication (warfarin, aspirin, or clopidogrel) after stroke, adjusting for age, race, sex, hypertension and other comorbidities, and the pharmacotherapies prescribed. We used propensity scores to adjust for confounding by indication. RESULTS: Among 925 stroke patients (64.6% female, 75.1% > or =50 years, and 57.8% African American), hypertension and heart disease were the most prevalent comorbidities (66.1% and 65.1%, respectively); most initial strokes were nonhemorrhagic. Persistence of use of warfarin, aspirin, or clopidogrel after stroke increased the likelihood of avoiding a recurrence (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.22-2.01). Having a hemorrhagic stroke initially (HR, 0.37; 95% CI, 0.18-0.74) or having heart disease (HR, 0.82; 95% CI, 0.67-1.01), hypertension (HR, 0.63; 95% CI, 0.51-0.79), or diabetes mellitus (HR, 0.74; 95% CI, 0.60-0.91) after an initial stroke significantly decreased the likelihood of avoiding a recurrence. Patient's age, race, sex, and urban residence did not significantly predict the likelihood of avoiding a recurrence. CONCLUSIONS: Persistence of use of the initial stroke preventive medication after stroke is effective in avoiding a recurrence. Hemorrhagic stroke, heart disease, hypertension, and diabetes increase the likelihood of a recurrence.

Adult↗
PubMed2005

Health disparities: a barrier to high-quality care.

PURPOSE: Disparities in the treatment of cardiovascular disease, diabetes mellitus, and cancer among the sexes and racial groups and possible interventions are discussed. SUMMARY: The ongoing process to identify and reduce health disparities has engaged numerous federal agencies as they monitor the nation's progress toward policy-driven and health-related objectives. Cardiovascular disease disproportionately affects minority groups and is the leading cause of death among women in the United States, and both groups receive suboptimal care for the disease. Disparities in the treatment of diabetes mellitus in African Americans, women, patients with less than a high school education, and the elderly have been found. Many minority groups continue to suffer disproportionately from cancer. Racial disparities also exist in cancer screening and treatment. Minorities are underrepresented in clinical trials for multiple reasons, many of which may be related to cultural beliefs. At all levels of coinsurance, the poor are less likely to seek preventive care. Adherence to national screening and treatment guidelines, clinical trial recruitment and participation, addressing language and geographic barriers, and increasing access to insurance are part of the coordinated efforts required to reduce health disparities. Because pharmacists influence patients' health status directly through pharmaceutical care and indirectly by engaging patients in their treatment, it is essential for pharmacists to be able to provide culturally competent care. CONCLUSION: Despite significant efforts over the past several years, health disparities continue to exist, particularly among minority groups. Interventions aimed at eliminating these disparities should include ensuring cultural competence among health care providers and improving health literacy among patients.

Attitude of Health Personnel↗
PubMed2005

Selective cyclooxygenase-2 inhibition and cardiovascular effects: an observational study of a Medicaid population.

BACKGROUND: The differential effects of selective cyclooxygenase-2 (COX-2) inhibitors compared with nonspecific nonsteroidal anti-inflammatory agents (NSAIDs) on platelet aggregation and prostacyclin/thromboxane balance have led to concerns that COX-2 inhibitors may increase the risk for cardiovascular thrombotic events. Empirical studies have generally been limited to analyses of secondary end points with low event rates in clinical trials and single event rates in observational studies, all of which have come to conflicting conclusions. This observational cohort study examines the cardiovascular risk of COX-2 inhibitors compared with nonspecific NSAIDs in Maryland Medicaid enrollees, a high-risk population. METHODS: Medical and prescription claims were analyzed for noninstitutionalized Medicaid enrollees who received at least a 60-day supply of a COX-2 inhibitor or other prescription NSAID between June 2000 and June 2002 and who did not use these drugs for at least 6 months prior. Naproxen users were excluded. We developed a logistic model of propensity for treatment with COX-2 inhibitors and stratified patients by quintiles of their propensity score. The model adjusted for demographics, indications for COX-2 inhibitors, and cardiovascular risk factors. RESULTS: The study population comprised 1005 patients using COX-2 inhibitors and 5245 patients using a nonnaproxen NSAID. Of the 6250 patients, 70% were female, 50% were African American, and 30% were older than 50 years. Overall, 12% of the patients had at least 1 cardiovascular thrombotic event after treatment within the follow-up period. The propensity-adjusted odds ratio showed no significant effect of COX-2 inhibitor use on this percentage of patients (odds ratio, 1.09; 95% confidence interval, 0.90-1.33). CONCLUSION: We did not find that COX-2 inhibitors increased cardiovascular risk over nonnaproxen NSAIDs in a high-risk Medicaid population.

Adolescent↗
PubMed2005

Persistence, switching, and discontinuation rates among patients receiving sertraline, paroxetine, and citalopram.

STUDY OBJECTIVE: To compare persistence, switching, and discontinuation rates among patients taking brand-name selective serotonin reuptake inhibitors (SSRIs). DESIGN: Retrospective cohort study. Data Source. Protocare Sciences managed care database. PATIENTS: A total of 14,933 patients with depression, posttraumatic stress disorder, or social anxiety disorder whose prescriptions for brand-name SSRIs were filled from January 1, 1999-June 30, 2002. MEASUREMENTS AND MAIN RESULTS: A total of 5598 patients received sertraline, 4131 citalopram, and 5204 paroxetine. Adherence status was categorized as persistence, switching (from one SSRI to another SSRI), and discontinuation. Persistence was determined based on the number of days' supply of the prescribed drug, with a minimum of 15 days to refill. Survival analyses using life-table survival curves and Cox proportional hazard models were conducted. Age, sex, and copayment were covariates in the Cox proportional models. Sensitivity analysis with a longer time to refill was performed to determine whether the results were sensitive to the algorithm for determining adherence. Compared with patients receiving sertraline and citalopram, those receiving paroxetine had lower rates of persistence (23.79% vs 25.96% for sertraline [p = 0.0093] and 26.56% for citalopram [p = 0.0022]) and higher rates of switching (3.55% vs 3.32% for sertraline [p = 0.5076] and 2.78% for citalopram [p = 0.0359]) and discontinuation (72.66% vs 70.72% for sertraline [p = 0.0258] and 70.66% for citalopram [p = 0.0334]). Survival curves showed that persistence rates with sertraline and citalopram were significantly greater than with paroxetine (p<0.05, log-rank and Wilcoxon tests). Age was an independent predictor of persistence; male sex and copayment were not. The comparisons across SSRIs were robust in the sensitivity analysis that varied the time to refill allowed. CONCLUSION: Differences in the persistence rates were noted among patients receiving three brand-name SSRIs, with patients receiving paroxetine having lower persistence than those receiving sertraline and citalopram. Observed differences in persistence across SSRIs were not sensitive to model specifications. Prescription of SSRIs that demonstrate better adherence would benefit both the patient and the health care system.

Adolescent↗
PubMed2005

Triptans for migraine therapy: a comparison based on number needed to treat and doses needed to treat.

OBJECTIVE: Managed care and other decision makers need sound comparative information to support the formulary selection process and reimbursement decisions for the treatment of migraine. The objective of this study was to compare currently marketed triptan therapies using number-needed-to-treat (NNT) and doses-needed-to-treat (DNT) measures. DNT was further used to derive triptan treatment cost to achieve 100 successfully treated patients such that the cost-effectiveness of each treatment regime could be compared from the payer perspective. METHODS: Using published meta-analysis data to categorize patients as treatment success or failure, an NNT and a DNT were derived for each triptan. Treatment success was defined as achieving a 2-hour pain response, sustained through 24 hours postdose. Costs were derived by multiplying DNT by the average wholesale price (AWP) minus 15% for each triptan. RESULTS: Eletriptan 40 mg had the lowest NNT, with 361 patients needing to be treated in order to have 100 patients achieve clinical benefit; rizatriptan 5 mg had the highest NNT (597 patients). Eletriptan 40 mg required 388 doses to successfully treat 100 patients.the lowest number of doses of the triptans considered; rizatriptan 5 mg required the highest number (662 doses). Eletriptan 40 mg had the lowest total triptan cost of USD 5,630 to successfully treat 100 patients. The highest total triptan cost of treatment was USD 11,136 for naratriptan 2.5 mg. CONCLUSIONS: Eletriptan 40 mg provides the best value in terms of the lowest DNT, assuming an approximately equal AWP discount for each triptan. Eletriptan 40 mg also was found to have the lowest total triptan cost to successfully treat 100 patients. Future research should further explore the utility of DNT in managed care decision making.

Algorithms↗