Determination of phosphine in plant materials: method optimization and validation in interlaboratory comparison tests.

The optimization and validation of a method for the determination of phosphine in plant materials are described. The method is based on headspace sampling over the sample heated in 5% sulfuric acid. Critical factors such as sample amount, equilibration conditions, method of quantitation, and matrix effects are discussed, and validation data are presented. Grinding of coarse samples does not lead to lower results and is a prerequisite for standard addition experiments, which present the most reliable approach for quantitation because of notable matrix effects. Two interlaboratory comparisons showed that results varied considerably and that an uncertainty of measurement of about 50% has to be assessed. Flame photometric and mass spectrometric detection gave similar results. The proposed method is well reproducible within one laboratory, and results from the authors' laboratories using different injection and detection techniques are very close to each other. The considerable variation in the interlaboratory comparison shows that this analysis is still challenging in practice and further proficiency testing is needed.

Comorbidities at multiple sclerosis diagnosis.

The nature and frequency of comorbidities upon notification of multiple sclerosis (MS) are not well known. In France, MS is one of the 30 long-term illnesses (affections de longue durée, ALD) for which 100 % of patients' health care costs are covered by the main French health insurance system. We conducted a study among 22,087 patients who had contracted MS before their 45th birthday and had obtained ALD status between 1995 and 2004. Comorbidities diagnosed at MS notification were described. The age at which MS was registered in patients with a previous comorbidity was compared with that in those patients with no previous comorbidities. Among the 22,087 patients, 21,119 (95 %) had ALD status for MS only, 653 (3 %) had a comorbidity status diagnosed at the same time as MS. Of these comorbidities, 86.8 % could be grouped into five main categories: psychiatric disease (40.2 %), autoimmune disease (24.5 %), cardiovascular disease (16.2 %), cancer (12.2 %), and metabolic disease (9.0 %). Psychiatric disorders and diabetes were more frequent in MS patients than in the general population of the same age. The mean age at request for ALD status for MS in patients with no comorbidity was 33.6 ± 7.2 years, whereas it was 36.9 ± 6.5 years in those with comorbidities. Comorbidities at MS notification are rare. Psychiatric disorders and diabetes were more frequent in MS patients than in the general population.

Geographic variations of multiple sclerosis in France.

France is located in an area with a medium to high prevalence of multiple sclerosis, where its epidemiology is not well known. We estimated the national and regional prevalence of multiple sclerosis in France on 31 October 2004 and the incidence between 31 October 2003 and 31 October 2004 based on data from the main French health insurance system: the Caisse Nationale d'Assurance Maladie des Travailleurs Salariés. The Caisse Nationale d'Assurance Maladie des Travailleurs Salariés insures 87% of the French population. We analysed geographic variations in the prevalence and incidence of multiple sclerosis in France using the Bayesian approach. On the 31 October 2004, 49 417 people were registered with multiple sclerosis out of the 52 359 912 insured with the Caisse Nationale d'Assurance Maladie des Travailleurs Salariés. Among these, 4497 were new multiple sclerosis cases declared between 31 October 2003 and 31 October 2004. After standardization for age, total multiple sclerosis prevalence in France was 94.7 per 100,000 (94.3-95.1); 130.5 (129.8-131.2) in females and 54.8 (54.4-55.3) in males. The national incidence of multiple sclerosis between 31 October 2003 and 31 October 2004 was 7.5 per 100,000 (7.3-7.6); 10.4 (10.2-10.6) in females and 4.2 (4.0-4.3) in males. The prevalence and incidence of multiple sclerosis were higher in North-Eastern France, but there was no obvious North-South gradient. This study is the first performed among a representative population of France (87%) using the same method throughout. The Bayesian approach, which takes into account spatial heterogeneity among geographical units and spatial autocorrelation, did not confirm the existence of a prevalence gradient but only a higher prevalence of multiple sclerosis in North-Eastern France and a lower prevalence of multiple sclerosis in the Paris area and on the Mediterranean coast.

Cost of care of colorectal cancers according to health care patterns and stage at diagnosis in France.

Little is known about the economic burden associated with colorectal cancer in France. The aim of this study was to evaluate the effects of age, stage at diagnosis, health care pattern and level of comorbidities on the mean cost of the management of colorectal cancers, using data from a population-based registry and the French health care system. We estimated the direct costs of medical care for 384 colorectal cancers diagnosed in 2004, using the three main databases of the National Health Insurance. The cost of management was defined as the sum of all health expenditures over the 12 months following the date of diagnosis. The mean cost for first-year management was 24,966 euro (SE 1,195 euro). There was no significant difference in overall costs in relation to sex, age, Charlson index score, cancer location or health care pattern. Costs increased significantly with cancer extension from 17,596 euro for stage I to 35,059 euro for stage IV. Hospitalisation charges represented the greatest economic burden (55.2%), followed by medical purchases (24.4%), outpatient care (17.8%) and transportation (2.5%). These results confirm the major economic burden of colorectal cancer and indicate that total costs depend mainly on the stage at diagnosis. By improving stage at diagnosis, mass screening could contribute to decreasing the cost of managing colorectal cancers.