Biomedical subjects

Katia Noyes

Publications and source records attributed to Katia Noyes.

9 recordsLinked to original sources

PubMed2007

Accuracy of Medicare claims data in identifying Parkinsonism cases: comparison with the Medicare current beneficiary survey.

STUDY PURPOSE: Administrative databases are commonly used to examine use of healthcare service, with researchers relying on diagnostic codes to identify medical conditions. This study evaluates the accuracy of administrative claims in identifying Parkinsonism cases compared to the self-reported Parkinson's disease (PD). METHODS: The reference cases were identified based on the self-reported PD status and the use of PD drugs collected by the 1992-2000 Medicare Current Beneficiary Survey that contained 72,922 observations from 30,469 individuals. Using ICD-9 CM, cases with PD were extracted from the corresponding Medicare claims. We compared prevalence of PD obtained using different types of claims. RESULTS: The sensitivities were the highest when all claims were used (66%). All the specificities were greater than 99%. When drug use information was included in the gold standard, the sensitivities became lower, while the specificities and positive predictive values (PPVs) increased. Using more diagnostic codes improved the sensitivity of the identification process but reduced PPVs. CONCLUSIONS: Administrative claims can provide fairly accurate and practical approach to "rule in" patients with PD. Depending on the purpose of evaluation, researchers may consider using more categories of claims to improve the sensitivity of the identification algorithm or use fewer diagnoses to minimize number of false positive cases.

Aged↗

PubMed2006

What is the risk of developing parkinsonism following neuroleptic use?

Use of neuroleptic medications is common among elderly patients. Using multivariate models, the authors found that use of antipsychotic medications, age, and disability were strong predictors of developing self-reported Parkinson disease (PD) in the subsequent year among 1992 to 2000 Medicare Current Beneficiary Survey participants. Although more research is needed, these data suggest that 126 Medicare beneficiaries would need to be treated with neuroleptic medications to cause one additional case of self-reported PD.

Aged↗

PubMed2006

Economic burden associated with Parkinson's disease on elderly Medicare beneficiaries.

We evaluated medical utilization and economic burden of self-reported Parkinson's disease (PD) on patients and society. Using the 1992-2000 Medicare Current Beneficiary Survey, we compared health care utilization and expenditures (in 2002 U.S. dollars) of Medicare subscribers with and without PD, adjusting for sociodemographic characteristics and comorbidities. PD patients used significantly more health care services of all categories and paid significantly more out of pocket for their medical services than other elderly (mean+/- SE, 5,532 dollars+/- 329 dollars vs. 2,187 dollars+/- 38 dollars; P<0.001). After adjusting for other factors, PD patients had higher annual health care expenses than beneficiaries without PD (18,528 dollars vs. 10,818 dollars; P<0.001). PD patients were more likely to use medical care (OR=3.77; 95% CI=1.44-9.88), in particular for long-term care (OR=3.80; 95% CI=3.02-4.79) and home health care (OR=2.08; 95% CI=1.76-2.46). PD is associated with a significant economic burden to patients and society. Although more research is needed to understand the relationship between PD and medical expenditures and utilization, these findings have important implications for health care providers and payers that serve PD populations.

Activities of Daily Living↗

PubMed2006

Cost of caring for Medicare beneficiaries with Parkinson's disease: impact of the CMS-HCC risk-adjustment model.

Previous studies have demonstrated that Medicare risk-adjusted capitation models do not adequately compensate programs serving primarily disabled or frail populations. Using the Medicare Current Beneficiary Survey, we demonstrate that the Centers for Medicare and Medicaid Services-Hierarchical Condition Categories (CMS-HCC) model calculates Medicare capitation payments for Parkinson's patients more accurately than for the general population. The discrepancies between the predicted and actual expenditures estimated at various disability levels were smaller for Parkinson's patients than for other beneficiaries. If the CMS-HCC payment model were to apply to programs that draw a significant percentage of their participants from the Parkinson's disease community, these programs likely would be compensated fairly.

Aged↗

PubMed2005

Pramipexole and levodopa in early Parkinson's disease: dynamic changes in cost effectiveness.

BACKGROUND AND OBJECTIVE: In chronic disease, treatment effects and costs accumulate over time; hence, the choice of time horizon in cost-effectiveness analysis can be particularly important. In this article we analyse the dynamic changes in cumulative costs, effects and incremental cost effectiveness of two competing drug strategies in patients with early Parkinson's disease (PD). METHODS: Three hundred and one subjects with PD were randomised to initial pramipexole or levodopa and followed every 3 months over a 4-year period. Healthcare resource use was recorded in patient diaries and valued using a variety of sources at year 2002 US dollar values. Health-related quality of life (HRQoL) was measured using the EuroQoL EQ-5D. The study was conducted from a US societal perspective. Missing data were imputed using a multivariate fixed-effects model. Additional quality adjusted life years (QALY) gained by using pramipexole compared with levodopa were estimated as the area between the normalised treatment HRQoL profiles. The QALYs and costs for each treatment arm were calculated for various study horizons.The incremental cost-effectiveness ratio (ICER) and the net monetary benefit (NB) [using 50,000 US dollars, 100,000 US dollars and 150,000 US dollars as the value of a QALY] were estimated, and were bootstrapped to calculate the standard errors. Cost-effectiveness acceptability curves (CEAC) were built to estimate the probability that pramipexole was cost effective given different societal values of QALY, for various study horizons.We conducted sensitivity analyses on the ICER and the NB to test their robustness to various assumptions about missing data, for various subpopulations and under changes in the drug prices. RESULTS: Under the base-case assumptions, the ICER for pramipexole was 42,989 US dollars per QALY. Using the CEAC approach, the probability that pramipexole was cost effective relative to levodopa over the first 4 years was 0.57, 0.77 and 0.82 when a QALY was valued at 50,000 US dollars, 100,000 US dollars, and 150,000 US dollars, respectively. Over time, the ICER for pramipexole improved and uncertainty around the ICER decreased. If, after treatment withdrawal, HRQoL improved in pramipexole subjects and declined in levodopa subjects (best-case scenario for pramipexole), the probability of pramipexole being cost effective increased to 0.88, 0.96 and 0.98, respectively. Factors that improved the ICER of pramipexole were a decrease in the relative price of pramipexole and having low HRQoL or depression at baseline. CONCLUSIONS: The cost effectiveness of pramipexole compared with levodopa in the treatment of early PD increased as the time horizon of the clinical trial extended from 2 to 4 years. Our results suggest that pramipexole is more cost effective for patients with depression and low baseline HRQoL than in other patient subgroups.

Administration, Oral↗

PubMed2004

Teaching and evaluating first and second year medical students' practice of evidence-based medicine.

PURPOSE: To implement an evidence-based medicine (EBM) curriculum for Year 1 and 2 medical students, and to develop a method to evaluate their practice of EBM in discrete and relevant worksteps. METHODS: For the 100 students entering Year 1 of their medical education in 2000, we implemented a curriculum with 25-30 student contact hours of EBM instruction which used a variety of teaching formats and spanned the first and second years of their training. We developed an evaluation module that assessed the following 5 steps in the practice of EBM: generating well built questions; searching for evidence; critical appraisal; applying the evidence, and self-evaluation. We tested 2 different versions of the test module 3-months apart with the same cohort of second year students, and correlated their scores on the second module with examination components of a comprehensive assessment. We obtained feedback from the students regarding the EBM curriculum and evaluation method. RESULTS: Each test module took 2-4 hours to complete and 5-8 minutes to grade. There was moderate test-retest reliability for the total test scores (r = 0.35, P < 0.001). Step 1 scores correlated with the mock board examination scores (r = 0.23, P = 0.05). Step 2 scores correlated with the peer assessment factor "work habits" (r = 0.24, P = 0.02), and Step 3 scores correlated with clinical reasoning exercises (r = 0.31, P = 0.002). Step 4 scores lacked test-retest reliability and did not correlate with components of the comprehensive assessment. The majority of students felt there was too much focus on EBM during the first 2 years of the curriculum and they rated the EBM test module the lowest rated component of the comprehensive assessment. CONCLUSIONS: Although we have demonstrated preliminary reliability and validity of a new evaluation instrument that assess the domains of scientific knowledge, work habits and reasoning skills required in the practice of EBM, many of the correlations were weak, and we remain in the very early stages of determining if, when and how EBM instruction should occur in medical education.

Adult↗

PubMed2004

Evidence from cost-effectiveness research.

Economic evaluations are a set of outcomes and health services research methods to inform the debate about the rising cost of health care and include cost-of-illness studies and cost-effectiveness research. Cost-effectiveness research is the comparative analysis of two or more alternative interventions in terms of their health and economic consequences, whose results are expressed as an incremental cost-effectiveness ratio, the ratio of differences in cost between a pair of medical interventions to the differences in the corresponding health effects. These research methods are particularly important to neurological diseases with debilitating natural histories, long-term courses, and a growing number of exciting, yet costly, treatment options available. The results of economic evaluations of neurological conditions influence resource allocation decisions, help set reimbursement rates, estimate future healthcare expenses, and improve the quality and efficiency of delivering neurological care. For these research methods to achieve their potential, continued methodological advances within the field are needed, as well as a more systematic integration of these methods into mainstream research to address critical questions regarding the health and well-being of patients with neurological illness.

Biomedical Research↗

PubMedDate not supplied

Pramipexole versus levodopa in patients with early Parkinson's disease: effect on generic and disease-specific quality of life.

OBJECTIVE: Although health-related quality of life (HRQOL) has been included in multiple Parkinson's disease (PD) clinical trials, little is known about how HRQOL responds to treatments over time. Here we assess the effect of therapy on HRQOL and explore factors that influence the HRQOL profiles and subdomains. METHOD: A total of 301 subjects with early PD were randomized to either initial pramipexole or initial levodopa and followed every 3 months over a 4-year period. To estimate health outcomes, we used EQ-5D and PDQUALIF. We calculated the incremental effectiveness as the accumulated difference in the total HRQOL over time between treatments. The subgroup analyses (by sex, race, age, baseline patient characteristics, and occurrence of adverse events) were conducted using the same approach. Sensitivity analysis was performed to test the effect of missing data imputation on the results. RESULTS: All three HRQOL measures resulted in similar profiles over time characterized by initial improvement over the first 3 to 6 months and followed by a gradual decline in years 2, 3, and 4. The difference in HRQOL between the treatment arms widened in favor of pramipexole in years 3 and 4 for all HRQOL measures used (EQ-5D: Y3 0.048, P = 0.03; Y4 0.071, P = 0.04). Our analyses suggested that the effect of pramipexole on HRQOL was mediated through nonmotor functions, whereas levodopa improved primarily motor domains of HRQOL. CONCLUSION: Our results suggest that pramipexole and levodopa affect patient HRQOL via improvement on different domains of well-being: nonmotor effect for pramipexole and mobility improvement for levodopa.

Antiparkinson Agents↗

PubMedDate not supplied

Pramipexole v. levodopa as initial treatment for Parkinson's disease: a randomized clinical-economic trial.

PURPOSE: To determine the 2-year incremental cost effectiveness of initial pramipexole treatment compared with initial levodopa treatment in patients with early Parkinson's disease (PD). METHODS: 301 subjects with early PD were randomized to either pramipexole or levodopa and followed every 3 months over a 2-year period. Costs were assigned to patient collected health utilization data using a variety of methods. Health state preferences were estimated using the EuroQol. RESULTS: Pramipexole strategy was an estimated 2,138 dollars (SE = 1,182 dollars) more expensive than levodopa strategy. The incremental cost-effectiveness of pramipexole compared with levodopa was 106,900 dollars/QALY (EQ-5D), compared with pramipexole being dominated by levodopa using the EQVAS. CONCLUSIONS: Although considerable uncertainty exists in the 2-year cost-effectiveness of initial pramipexole compared with initial levodopa in the treatment of early PD, our estimates suggest that pramipexole may not be welfare enhancing during the first 2 years of treatment. If initial pramipexole results in long-term improvements in quality of life, its cost-effectiveness will become more favorable.

Adult↗