[Validation of data collection for an American trypanosomiasis epidemiologic study in the State of Morelos, México]. / Validación del proceso de obtención de datos para un estudio sobre trypanosomiasis americana en el estado de Morelos, México.

The purpose of this paper is to show up the importance of the standardization concepts in American Trypanosomiasis epidemiological studies. The consistence in the measurement of some dwelling characteristics was evaluated. A validation of the Queretaro antigen for indirect hemagglutination reaction as a diagnostic test and the interobserver concordance for the serologic readings were also made. The observers were instructed in some sessions. The pretests were made in the laboratory with positive and negative sera, with sera from the studied population. Results show that the interobserver concordance after the instruction, for the dwelling variables ranged from 70% to 100%. Sensitivity of the Queretaro antigen was 100%, specificity 55%, the predictive value of a positive test 55%, and the predictive value of a negative test 93%. The interobserver concordance was 47%. The pretest and the pilot study are very important in getting the objectives of the principal study.

High blood pressure and cardiovascular risk factors in an adult population of Mexico City. Characteristics of the studied population.

The present report is a description of the characteristics of a studied population and of the methodology used in a study performed to investigate high blood pressure prevalence and cardiovascular risk factors among the adult population of Mexico City. A cross-sectional study was conducted from January 1991 to March 1992. Random samplings of multiple stages was used and 825 adult subjects were studied in Mexico City. The following measurements were registered: blood pressure, body mass index (BMI), waist-hip ratio (WHR), total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL-C) and low density lipoproteins (LDL-C), lipoprotein (a) (Lp(a)), glucose and insulin. Personal and family history of cardiovascular illness were investigated, as well as exposure to some risk factors such as smoking, alcohol consumption and sedentarism. The response rate was 86.6%. The prevalence of high blood pressure was 21.1%, and of non-insulin dependent diabetes mellitus was 8.7%. Frequency of dyslipidemia in the studied sample was 24.4% for high TG, 23.6% for low HDL-C, 23.6% for high LDL-C, 14.9% for Lp(a) excess (Lp(a) > or = 30 mg/dl; overweight and obesity were more prevalent among women. The diversity of living conditions among the population of Mexico City was included in the sampling strategy design, not only to register the high blood pressure (HBP) frequency in each stratum but to identify other cardiovascular risk factors which could be decisive in the development of HBP. Regarding the features of the studied population, BMI did not reveal differences among men, but their TG levels were higher and HDL levels lower than those of other populations. In women, the results obtained for BMI, WHR, lipids and lipoproteins were also higher compared with the mean reported for other populations.