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O Zurriaga

Publications and source records attributed to O Zurriaga.

10 recordsLinked to original sources
PubMed2006

Analysis of the renal transplant waiting list in the País Valencià (Spain).

In this paper we analyse the renal transplant waiting list of the País Valencià in Spain, using Queueing theory. The customers of this queue are patients with end-stage renal failure waiting for a kidney transplant. We set up a simplified model to represent the flow of the customers through the system, and perform Bayesian inference to estimate parameters in the model. Finally, we consider several scenarios by tuning the estimations achieved and computationally simulate the behaviour of the queue under each one. The results indicate that the system could reach equilibrium at some point in the future and the model forecasts a slow decrease in the size of the waiting list in the short and middle term.

Bayes Theorem↗
PubMed2002

[Analysis of survival in dialysis: hemodialysis versus peritoneal dialysis and the significance of comorbidity].

To choose the best possible dialysis technique for those patients with end-stage renal disease continues to be a matter of debate. Even after putting aside the evident influence that economic and geographic factors as well as the health politics may have in the selection of the technique, different studies comparing survival between hemodialysis (HD) and peritoneal dialysis (PD) have shown contradictory results which could be explained by the differing methodological and statistical methods used together with the different influence assigned to the comorbidity found when starting the treatment, a situation that has increased the confusion about this topic. Based on this we performed a retrospective analysis with a follow-up time of seven years including all those patients who started dialytic treatment in our area, with a final number of 3.106 hemodialysis patients and 542 peritoneal dialysis patients. Those patients who were transferred to another treatment technique during the time of the study were excluded. Age higher than 70 years, cardiovascular disease, liver disease, diabetes mellitus and the presence of dyslipidemia were included as comorbidity factors. Peritoneal dialysis patients were younger than those treated by hemodialysis (54.53 vs 60.1 years), but suffered from higher cardiovascular comorbidity and were more often diabetic. The global survival was the same in both groups up to 32 months of treatment. Although no differences were found when comparing those patients without comorbidity factors, those with comorbidity had better survival on hemodialysis. Age higher than 70 years was the only comorbidity factor with statistically significant difference for a better survival in hemodialysis.

Adolescent↗
PubMedDate not supplied

[Incorporation of geostatistical methodology for influenza surveillance in a sentinel network].

OBJECTIVES: To evaluate geostatistical description of influenza data from the Valencian Sentinel Network (VSN) in Spain using the kringing method and to assess the possibility of incorporating this method into routine surveillance. METHODS: We use influenza surveillance data on three influenza seasons (1997-1998, 1998-1999 and 1999-2000) from the VSN to construct a geocodified data matrix of the incidence of this disease. The geographic distribution was studied using the kringing method, which enables estimation of the incidence in a few strategically distributed points. Influenza isoincidence maps for each week were plotted. Cross validation was used to evaluate the method. RESULTS: In most of the weeks, the values of reduced standard deviation and reduced mean were close to the optimal values (0 and 1, respectively). Out of range reduced standard deviation values were found in 12 of 20 weeks in the last season only. The estimation of rates in all three seasons showed coherence in spatial distribution and temporal evolution. CONCLUSIONS: In most situations the results were acceptable. The method does not require extra computer resources or an excessive amount of time and requires only annual adaptation. Because it is easy to use, the technique is appropriate for routine use but the accuracy of estimations could be improved by increasing the complexity of the model.

Geographic Information Systems↗
PubMedDate not supplied

[Point processes as a tool for analyzing possible sources of contamination].

Point pattern analysis pattern comprises a series of techniques that enables the distribution of a series of events occurring in the vicinity of a particular region of a map to be studied. In epidemiology, this problem arises when a potential source of environmental contamination, possibly leading to cases of a specific disease, is investigated.The present study provides a brief description of point pattern analysis. The approach is illustrated through determination of the environmental source and study of the areas of greatest risk of incidence of an outbreak of legionella pneumonia that occurred between the middle of September and beginning of October in the city of Alcoi in Alicante (Spain).Point pattern analysis was able to confirm the environmental source of the outbreak and identify the areas of the city at greatest risk. This provided the justification for an exhaustive inspection of the installations generating aerosols after which, to date, the epidemics ceased.

Environmental Microbiology↗
PubMedDate not supplied

[A morbidity information system based on school absenteeism].

We present a pilot experience about the introduction of a information system designed for the knowledge of infant morbidity (4-15 years) in a 13 school week period in a representative sample of 60 schools of the Valencian Community. We studied school absences that lasted three days or longer. Reports of teachers and parents were the source of information (100% response rate). Medical certification was also requested to the pediatricians and general practitioners of the area of the schools (12.74% response rate). To test the validity of this information system, absences caused by hepatitis were compared with the registry of Notifiable Diseases System (NDS) for the same period. We recorded 3,968 absences, with a cumulative incidence of 100.68 per 1,000 (C.I., alpha = .05, +/- 4.97) for females, and 119.4 (C.I., alpha = .05, +/- 18.36) for males. These differences were statistically significant. There was a concordance of 80.25% of the hepatitis cases between the registry of absenteeism and that of the NDS (chi 2 goodness of fit test = 3.16, p = .754). Although absences shorter than 3 days were not taken into account, the information system provided relevant and valid estimates of morbidity. Moreover, collaboration of teachers was considered very positive, which led us to use this health information system in five health areas of the Valencian Community.

Absenteeism↗