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Joan Rovira

Publications and source records attributed to Joan Rovira.

11 recordsLinked to original sources
PubMed2006

Clinical trial optimization: Monte Carlo simulation Markov model for planning clinical trials recruitment.

INTRODUCTION: The patient recruitment process of clinical trials is an essential element which needs to be designed properly. METHODS: In this paper we describe different simulation models under continuous and discrete time assumptions for the design of recruitment in clinical trials. RESULTS: The results of hypothetical examples of clinical trial recruitments are presented. The recruitment time is calculated and the number of recruited patients is quantified for a given time and probability of recruitment. The expected delay and the effective recruitment durations are estimated using both continuous and discrete time modeling. CONCLUSION: The proposed type of Monte Carlo simulation Markov models will enable optimization of the recruitment process and the estimation and the calibration of its parameters to aid the proposed clinical trials. A continuous time simulation may minimize the duration of the recruitment and, consequently, the total duration of the trial.

Clinical Trials as Topic↗
PubMed2006

Analysis of the World Bank's pharmaceutical lending.

This article analyzes the World Bank's lending activity on pharmaceuticals and medical products (PMP) during the fiscal years (FY) 1999-2001 by regions, borrower and supplier country, and procurement method. Data for the study derived from the World Bank Project and the Business Warehouse databases. The information included all Bank projects approved during the study period. Information for the PMP procurement contracts was extracted for the health sector components of all sector projects awarded. Contract dollar amount was aggregated by borrower and supplier countries. A total of 365 contracts of PMP for a value of US$ 364.5 million (2001 prices) were awarded. International competitive bidding was the most common procurement method used representing 46.0% of the total PMP contracts amount. Domestic providers supplied 52.5% of the PMP contracts managed by the borrower countries. Twenty-two countries accounted for 97.0% of the total PMP purchased during the period of analysis. Only a small fraction of the Bank activity was directed to the pharmaceutical sector. There is a need for more involvement of the World Bank to increase accessibility, affordability and rational use of pharmaceuticals and medical products. An evaluation of the different procurement methods and their implications on drug quality and prices should be performed.

Databases as Topic↗
PubMed2006

Validation by simulation of a clinical trial model using the standardized mean and variance criteria.

OBJECTIVE: To develop and validate a model of a clinical trial that evaluates the changes in cholesterol level as a surrogate marker for lipodystrophy in HIV subjects under alternative antiretroviral regimes, i.e., treatment with Protease Inhibitors vs. a combination of nevirapine and other antiretroviral drugs. METHODS: Five simulation models were developed based on different assumptions, on treatment variability and pattern of cholesterol reduction over time. The last recorded cholesterol level, the difference from the baseline, the average difference from the baseline and level evolution, are the considered endpoints. Specific validation criteria based on a 10% minus or plus standardized distance in means and variances were used to compare the real and the simulated data. RESULTS: The validity criterion was met by all models for considered endpoints. However, only two models met the validity criterion when all endpoints were considered. The model based on the assumption that within-subjects variability of cholesterol levels changes over time is the one that minimizes the validity criterion, standardized distance equal to or less than 1% minus or plus. CONCLUSION: Simulation is a useful technique for calibration, estimation, and evaluation of models, which allows us to relax the often overly restrictive assumptions regarding parameters required by analytical approaches. The validity criterion can also be used to select the preferred model for design optimization, until additional data are obtained allowing an external validation of the model.

Anti-Retroviral Agents↗
PubMed2005

Antibiotic prescription in primary health care: clinical and economic perspectives (Catalonia, Spain).

OBJECTIVE: To quantify clinical inappropriateness of antibiotic prescription and its costs in primary health care. METHODS: 2470 cases of infectious disease during 1998 were analysed. RESULTS: Of all cases, 69.9% did not require antibiotic treatment. Global clinical inappropriateness amounted to 43.7%, rising to 56.7% with the introduction of economic criteria. Treatment unnecessary but antibiotic provided (27.9%) represented the most important category. Costs of inappropriateness reached 68.4% of the estimated total cost. CONCLUSION: Appropriate antibiotic use should be focused on reducing antibiotic prescription when not indicated and restraining the use of penicillins maintaining restrictive and adequate health policies, and also achieving co-responsibility from the general population.

Adult↗
PubMed2005

Health-care decision-making processes in Latin America: problems and prospects for the use of economic evaluation.

OBJECTIVES: The use of economic evaluation studies (EE) in the decision-making process within the health-care system of nine Latin American (LA) and three European countries was investigated. The aim was to identify the opportunities, obstacles, and changes needed to facilitate the introduction of EE as a formal tool in health-care decision-making processes in LA. METHODS: A comparative study was conducted based on existing literature and information provided through a questionnaire applied to decision makers in Argentina, Brazil, Colombia, Cuba, Mexico, Nicaragua, Peru, Portugal Spain, United Kingdom, Uruguay, and Venezuela. Systematic electronic searches of HEED, NHS EED, and LILACS were conducted to identify published economic evaluation studies in LA from 1982 onward. RESULTS: There is relatively little evidence of the conduct and use of EE within the health care systems in LA. Electronic searches retrieved 554 records; however, only 93 were EE. In the nine LA participating countries, broad allocation of health-care resources is primarily based on political criteria, historical records, geographical areas, and specific groups of patients and diseases. Public-health provision and inclusion of services in health-insurance package are responsibilities of the Ministry of Health. Decisions regarding the purchase of medicines are primarily made through public tenders, and mainly based on differences in clinical efficacy and the price of health technologies of interest. CONCLUSIONS: To expedite the process of incorporating EE as a formal tool to inform decision-making processes within the health-care systems in LA countries, two main conditions need to be fulfilled. First, adequate resources and skills need to be available to conduct EE of good quality. Second, decision-making procedures need to be modified to accommodate "evidence-based" approaches such as EE.

Biomedical Technology↗
PubMed2003

Assessing the economic impact of adverse drug effects.

Although most commonly used drugs cause adverse effects, some of them with potentially serious consequences, relatively little is known about their economic impact. The purpose of this review is to summarise information describing the cost of treatment of drug-induced adverse effects as an additional cost of pharmaceutical treatment. The focus of this study was limited to the overall economic impact of drug-related morbidity and to the economic analysis of a single class of drugs with different safety profiles. Several studies carried out in the US have investigated adverse drug effects experienced by hospitalised patients and their impact on hospital costs. Patients who developed adverse effects were hospitalised an average of 1.2-3.8 days longer than patients who did not, with additional hospital costs of $US2284-5640 per patient (2000 values). Other research studies in different countries have quantified the incidence and economic consequences of adverse drug effects that occur in the ambulatory setting and that generate hospital admission and emergency department visits. They have shown that preventable adverse effects constitute between 43.3% and 80% of all adverse outcomes leading to emergency visits and hospital admissions, and disproportionately increase healthcare costs. Finally, a recent estimation revealed that in the US the cost of problems linked to drug use in the ambulatory setting exceeded $US177 billion in the year 2000.NSAIDs constitute a widely used class of drugs and they are one of the leading drug classes in causing adverse effects. The acquisition costs of the drugs, as well as the costs for prevention and treatment of adverse effects, determine their cost-effectiveness ratio. Depending on the incidence and severity of adverse effects, the cost per adverse effect avoided ranges from $US215 to $US35 459 (2000 values). According to the contingent valuation methodology, willingness to pay to avoid or reduce the incidence of adverse effects is an indicator of the value individuals associate with the impact of such effects on their well-being. Individuals are willing to pay annually an average of $US240 and $US350, respectively, to avoid vomiting and gastrointestinal distress induced by NSAIDs. Although the results of the different studies reviewed are not strictly comparable because of differences in the severity of adverse effects, the perspective of the analysis, the cost data included and the cost component considered, the data show that, apart from the implications for health, a substantial quantity of resources are used to treat adverse effects.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Economic evaluation of triflusal and aspirin in the treatment of acute myocardial infarction.

OBJECTIVE: To compare the costs to the Spanish healthcare system of 35 days' treatment with triflusal (600 mg/day) and aspirin (300 mg/day) in patients with confirmed acute myocardial infarction within 24 hours of onset of symptoms. DESIGN: A cost minimisation analysis based on the results of the Triflusal in Acute Myocardial Infarction study (TIM) was conducted. The hypothesis was that despite a higher acquisition cost of triflusal, savings would result because of differences in efficacy and safety outcome (non-fatal cerebrovascular event and haemorrhagic events). Diagnostic Related Groups were used as a proxy for determining hospital costs in Spain and the values were obtained from different sources and refer to year 2000 costs. Only direct medical costs were considered for the economic analysis. RESULTS: Although the acquisition cost of triflusal was more expensive than that of aspirin, the cost of prevented events - non-fatal ischaemic cerebrovascular events and cerebral haemorrhages - entirely compensated for the cost of triflusal. The overall cost of treating patients with triflusal, compared with aspirin, represented a net saving of 28.4% per patient treated. CONCLUSION: Our study showed that triflusal is cost saving compared with aspirin in the treatment of the acute phase of myocardial infarction.

Acute Disease↗