Reported Estimates (reported + estimate)

Distribution by Scientific Domains


Selected Abstracts


Can cocaine use be evaluated through analysis of wastewater?

ADDICTION, Issue 5 2009
A nation-wide approach conducted in Belgium
ABSTRACT Aims Cocaine is the second most-used illicit drug world-wide and its consumption is increasing significantly, especially in western Europe. Until now, the annual prevalence has been estimated indirectly by means of interviews. A recently introduced and direct nation-wide approach based on measurements of the major urinary excreted metabolite of cocaine, benzoylecgonine, in wastewater is proposed. Design Wastewater samples from 41 wastewater treatment plants (WWTPs) in Belgium, covering approximately 3 700 000 residents, were collected. Each WWTP was sampled on Wednesdays and Sundays during two sampling campaigns in 2007,08. Samples were analysed for cocaine (COC) and its metabolites, benzoylecgonine (BE) and ecgonine methylester (EME) by a validated procedure based on liquid chromatography coupled with tandem mass spectrometry. Concentrations of BE were used to calculate cocaine consumption (g/day per 1000 inhabitants) for each WWTP region and for both sampling campaigns (g/year per 1000 inhabitants). Findings Weekend days showed significantly higher cocaine consumption compared with weekdays. The highest cocaine consumption was observed for WWTPs receiving wastewater from large cities, such as Antwerp, Brussels and Charleroi. Results were extrapolated for the total Belgian population and an estimation of a yearly prevalence of cocaine use was made based on various assumptions. An amount of 1.88 tonnes (t) per year [standard error (SE) 0.05 t] cocaine is consumed in Belgium, corresponding to a yearly prevalence of 0.80% (SE 0.02%) for the Belgian population aged 15,64 years. This result is in agreement with an earlier reported estimate of the Belgian prevalence of cocaine use conducted through socio-epidemiological studies (0.9% for people aged 15,64 years). Conclusions Wastewater analysis is a promising tool to evaluate cocaine consumption at both local and national scale. This rapid and direct estimation of the prevalence of cocaine use in Belgium corresponds with socio-epidemiological data. However, the strategy needs to be refined further to allow a more exact calculation of cocaine consumption from concentrations of BE in wastewater. [source]


Prevalence of epilepsy and seizures in the Navajo Nation 1998,2002

EPILEPSIA, Issue 10 2009
Karen Parko
Summary Purpose:, To determine the prevalence of epilepsy and seizures in the Navajo. Methods:, We studied 226,496 Navajo residing in the Navajo Reservation who had at least one medical encounter between October 1, 1998 and September 30, 2002. We ascertained and confirmed cases in two phases. First, we identified patients with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes signifying epilepsy or seizures using Indian Health Service (IHS) administrative data. Second, we reviewed medical charts of a geographic subpopulation of identified patients to confirm diagnoses and assess the positive predictive value of the ICD-9-CM codes in identifying patients with active epilepsy. Results:, Two percent of Navajo receiving IHS care were found to have an ICD-9-CM code consistent with epilepsy or seizures. Based on confirmed cases, the crude prevalence for the occurrence of any seizure (including febrile seizures and recurrent seizures that may have been provoked) in the geographic subpopulation was 13.5 per 1,000 and the crude prevalence of active epilepsy was 9.2 per 1,000. Prevalence was higher among males, children under 5 years of age, and older adults. Discussion:, The estimated prevalence of active epilepsy in the Navajo Nation is above the upper limit of the range of reported estimates from other comparable studies of U.S. communities. [source]


Meta-Analysis of Studies with Missing Data

BIOMETRICS, Issue 2 2009
Ying Yuan
Summary Consider a meta-analysis of studies with varying proportions of patient-level missing data, and assume that each primary study has made certain missing data adjustments so that the reported estimates of treatment effect size and variance are valid. These estimates of treatment effects can be combined across studies by standard meta-analytic methods, employing a random-effects model to account for heterogeneity across studies. However, we note that a meta-analysis based on the standard random-effects model will lead to biased estimates when the attrition rates of primary studies depend on the size of the underlying study-level treatment effect. Perhaps ignorable within each study, these types of missing data are in fact not ignorable in a meta-analysis. We propose three methods to correct the bias resulting from such missing data in a meta-analysis: reweighting the DerSimonian,Laird estimate by the completion rate; incorporating the completion rate into a Bayesian random-effects model; and inference based on a Bayesian shared-parameter model that includes the completion rate. We illustrate these methods through a meta-analysis of 16 published randomized trials that examined combined pharmacotherapy and psychological treatment for depression. [source]


Lacosamide as treatment of epileptic seizures , cost utility results for Sweden

ACTA NEUROLOGICA SCANDINAVICA, Issue 6 2010
K. Bolin
Bolin K, Berggren F, Forsgren L. Lacosamide as treatment of epileptic seizures , cost utility results for Sweden. Acta Neurol Scand: 2010: 121: 406,412. © 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Objectives,,, To calculate cost per additional quality-adjusted life-year (QALY) for lacosamide as adjunctive treatment for patients with uncontrolled partial-onset seizures as compared to no adjunctive treatment. Materials and methods,,, A decision-tree simulation model was constructed to calculate the number of seizures and health-care utilization for treated and untreated with lacosamide, respectively. Prices from 2007 were used for all costs. Results,,, All results were calculated for a 24-, 18-, 12- and 6-months follow-up. The cost per additional QALY was estimated to , 27,641 (24 months). Using a willingness-to-pay threshold for a QALY of , 50,000 the net marginal value of using lacosamide was estimated to about , 850,000 per 1000 patients. Conclusions,,, The estimated cost per QALY gained falls within the range of reported estimates of the willingness-to-pay for an additional QALY. The results imply that lacosamide is cost-effective in the treatment of uncontrolled partial-onset seizures (1 , , 9.6 SEK). [source]