La nueva oleada de la investigación en salud pública: de la evidencia a la política

[No disponible

Breast cancer in Mexican women: an epidemiological study with cervical cancer control

OBJETIVO: O câncer de mama (CM) é uma das principais causas de morte por câncer em mulheres, no México, com aumento da incidência e da mortalidade nos últimos anos. O estudo realizado objetivou identificar possíveis fatores de risco relacionados ao CM. MÉTODOS: Realizou-se um estudo epidemiológico de casos hospitalares de CM e de controles hospitalares com câncer cérvico-uterino (CACU) em oito hospitais de terceiro nível, na Cidade do México. Foram estudados 353 casos incidentes de CM e 630 controles com CACU, identificados entre mulheres com menos de 75 anos de idade, residentes na área metropolitana da Cidade do México pelo menos há um ano. O diagnóstico foi confirmado histologicamente em ambos os grupos. As variáveis foram analisadas de acordo com critérios aprovados biológica e estatisticamente. Foram efetuadas análises univariadas, bivariadas e multivariadas. Os casos e controles foram estratificados de acordo com o estado hormonal menopáusico (pré e pós-menopausa). Foi usado o odds ratio (OR) como método de associação com intervalos de confiança (IC) acima de 95%. RESULTADOS: Os fatores associados com o CM foram: nível socioeconômico alto (OR=2,77 IC 95% 1,77 -- 4,35); menarca prematura (OR=1,32 IC 95% 0,88 -- 2,00); idade acima de 31 anos quando da primeira gravidez (OR=5,49 IC 95% 21,16 -- 13,98) e um histórico familiar de CM (OR=4,76 IC 95% 2,10 -- 10,79). Por outro lado, um aumento na duração da amamentação foi um fator protetor (>; 25 meses OR=0,38 IC 95% 0,20 -- 0,77). CONCLUSÕES: Os resultados contribuíram para a identificação de fatores de risco para o CM descritos na literatura internacional na população de mulheres mexicanas. A amamentação parece exercer importante papel na proteção do CM. Em virtude das mudanças no estilo de vida das mulheres, as mulheres jovens tendem a diminuir seu período de amamentação.INTRODUCTION: In Mexico, breast cancer (BC) is one of the main causes of cancer deaths in women, with increasing incidence and mortality in recent years. Therefore, the aim of the study is identify possible risk factors related to BC. METHODS: An epidemiological study of hospital cases of BC and controls with cervical uterine cancer (CUCA) was carried out at eight third level concentration hospitals in Mexico City. The total of 353 incident cases of BC and 630 controls with CUCA were identified among women younger than 75 years who had been residents of the metropolitan area of Mexico City for at least one year. Diagnosis was confirmed histologically in both groups. Variables were analyzed according to biological and statistical plausibility criteria. Univariate, bivariate and multivariate analyses were carried out. Cases and controls were stratified according to the menopausal hormonal status (pre and post menopause). RESULTS: The factors associated with BC were: higher socioeconomic level (OR= 2.77; 95%CI = 1.77 - 4.35); early menarche (OR= 1.32; 95%CI= 0.88 - 2.00); old age at first pregnancy (>;31 years: OR= 5.49; 95%CI= 2.16 - 13.98) and a family history of BC (OR= 4.76; 95% CI= 2.10 - 10.79). In contrast, an increase in the duration of the breastfeeding period was a protective factor (>;25 months: OR= 0.38; 95%CI= 0.20 - 0.70). CONCLUSIONS: This study contributes to the identification of risk factors for BC described in the international literature, in the population of Mexican women. Breastfeeding appears to play an important role in protecting women from BC. Because of changes in women`s lifestyles, lactation is decreasing in Mexico, and young women tend not to breastfeed or to shorten the duration of lactation

Susceptibility to Smoking among Adolescents and Its Implications for Mexico’s Tobacco Control Programs. Analysis of the Global Youth Tobacco Survey 2003–2004 and 2006–2007

Smoking prevention efforts should either prevent target groups from becoming susceptible to smoking or prevent susceptible adolescents from progressing to becoming regular smokers. To describe the prevalence of susceptibility to smoking among never smoker students from cities that applied the GYTS in 2003 and 2006. The GYTS uses a two-stage cluster sample survey design that produces representative samples of students aged 12–15 years enrolled in public, private, and technical schools. The survey was undertaken at 399 schools in 9 cities. The GYTS surveyed 33,297 students during the academic years 2003–04 and 2006–07. Among never smokers, about 25% are likely to initiate smoking in the next 12 months. There are no differences in susceptibility to smoking by gender. When comparing results from 2003 and 2006, the susceptibility index has not changed, but for one city. The GYTS results are useful for monitoring susceptibility to smoking among adolescents and provide evidence for strengthening the efforts of tobacco control programs in Mexico

Pathogenicity island cag, vacA and IS605 genotypes in Mexican strains of Helicobacter pylori associated with peptic ulcers

<p>Abstract</p> <p>Background</p> <p><it>Helicobacter pylori </it>is associated with chronic gastritis, peptic ulcers, and gastric cancer. Two major virulence factors of <it>H. pylori </it>have been described: the pathogenicity island <it>cag </it>(<it>cag </it>PAI) and the vacuolating cytotoxin gene (<it>vacA</it>). Virtually all strains have a copy of <it>vacA</it>, but its genotype varies. The <it>cag </it>PAI is a region of 32 genes in which the insertion of IS<it>605 </it>elements in its middle region has been associated with partial or total deletions of it that have generated strains with varying virulence. Accordingly, the aim of this work was to determine the <it>cag </it>PAI integrity<it>, vacA </it>genotype and IS<it>605 </it>status in groups of isolates from Mexican patients with non-peptic ulcers (NPU), non-bleeding peptic ulcers (NBPU), and bleeding peptic ulcers (BPU).</p> <p>Methods</p> <p>The <it>cag </it>PAI integrity was performed by detection of eleven targeted genes along this locus using dot blot hybridization and PCR assays. The <it>vacA </it>allelic, <it>cag </it>PAI genotype 1 and IS<it>605 </it>status were determined by PCR analysis.</p> <p>Results</p> <p>Groups of 16-17 isolates (n = 50) from two patients with NPU, NBPU, and BPU, respectively, were studied. 90% (45/50) of the isolates harbored a complete <it>cag </it>PAI. Three BPU isolates lacked the <it>cag </it>PAI, and two of the NBPU had an incomplete <it>cag </it>PAI: the first isolate was negative for three of its genes, including deletion of the <it>cagA </it>gene, whereas the second did not have the <it>cagM </it>gene. Most of the strains (76%) had the <it>vacA </it>s1b/m1 genotype; meanwhile the IS<it>605 </it>was not present within the <it>cag </it>PAI of any strain but was detected elsewhere in the genome of 8% (4/50).</p> <p>Conclusion</p> <p>The patients had highly virulent strains since the most of them possessed a complete <it>cag </it>PAI and had a <it>vacA </it>s1b/m1 genotype. All the isolates presented the <it>cag </it>PAI without any IS<it>605 </it>insertion (genotype 1). Combined <it>vacA </it>genotypes showed that 1 NPU, 2 NBPU, and 1 BPU patients (66.6%) had a mixed infection; coexistence of <it>H. pylori </it>strains with different <it>cag </it>PAI status was observed in 1 NBPU and 2 BPU (50%) of the patients, but only two of these patients (NBPU and BPU) had different <it>vacA </it>genotypes.</p

Violência física intra-familiar entre jovens mexicanos e egípcios

OBJECTIVE: To determine the prevalence of experiencing intra-familial violence among Mexican and Egyptian youth and to describe its associated risk factors. METHODS: Data from questionnaires applied to 12,862 Mexican and 5,662 Egyptian youth, aged 10 to 19, who attended public schools were analyzed. Biviarate and logistic regression analysis were used to determine the relationship between socio-demographics, the experience of intra-familial violence and violence perpetration. RESULTS: The prevalence of having experienced intra-familial violence was comparable across the Mexican and Egyptian populations (14% and 17%, respectively). In Mexico, young men were more likely to have experienced such violence (OR=2.36) than women, whereas in Egypt, young women were at slightly greater risk than young men (OR=1.25). Older age, male gender and urban residence were independent correlates of experiencing intra-familial violence among Mexican youth. For Egyptian adolescents, in contrast, younger age, female gender and having non-married parents were independent correlates of victimization. Intra-familial violence victims were also more likely than non-victims to perpetrate violence (Mexico: OR=13.13; Egypt: OR=6.58). CONCLUSIONS: Mexican and Egyptian youth experienced intra-familial violence at a relatively low prevalence when compared with youth of other countries. A strong association was found between experiencing intra-familial violence and perpetrating violence.OBJETIVO: Determinar a prevalência da violência intra-familiar sofrida por jovens mexicanos e egípcios, e descrever os fatores de risco associados. MÉTODOS: Os dados analisados foram obtidos de questionários aplicados a 12.862 mexicanos e 5.662 egípcios, jovens de 10 a 19 anos, que freqüentam escolas públicas. O relacionamento entre fatores sociodemográficos, a violência sofrida e sua perpetração foram investigados por meio de análise bivariada e regressão logística. RESULTADOS: A prevalência de violência intra-familiar foi comparável entre as populações mexicana e egípcia (14% e 17%, respectivamente). No México, essa violência foi muito mais provável entre os homens jovens do que entre mulheres (OR=2,36), enquanto que no Egito era mais provável entre as mulheres jovens do que homens (OR=1,25). Idade mais elevada, gênero masculino e residência urbana são fatores associados a violência intra-familiar entre jovens mexicanos. Entre jovens egípcios, a idade mais baixa,o gênero feminino e pais não casados foram fatores associados a essa violência. Foi mais provável a repetição da violência pelos jovens que eram vítimas da violência intra-familiar (México: OR=13,13; Egito: OR=6,58). CONCLUSÕES: A prevalência de experimentar a violência intra-familiar de jovens mexicanos e egípcios foi baixa em comparação com jovens em outros países. Houve forte associação entre vítimas de violência intra-familiar e a repetição da violência

Evaluating the Validity of Self-Reported Smoking in Mexican Adolescents

Objectives We aimed to evaluate the validity of the self-reported smoking indicator used in the Global Youth Tobacco Survey (GYTS). Setting 43 middle and high-school classrooms from 26 schools were selected from Mexico City and Cuernavaca, Morelos. Participants A total of 1257 students provided both a questionnaire and a urine sample. Primary and secondary outcome Sensitivity and specificity of self-reported smoking compared to urinary cotinine. Validity indices were evaluated by subgroups of gender, social acceptability of smoking (ie, smoking parents or friends) and smoking frequency. Results Sensitivity and specificity for current smoking were 93.2% and 81.7%, respectively. Validity indices remained stable across gender. Parental smoking status moderated the validity of self-report, which had lower sensitivity in adolescents with non-smoking parents (86.7%) than in adolescents with smoking parents (96.6%). Sensitivity and specificity increased with smoking frequency. Conclusions This first validation study of self-reported current smoking used in the GYTS among Mexican adolescents suggests that self-reported smoking in the past 30 days is a valid and stable indicator of current smoking behaviour. This measure appears suitable for public health research and surveillance

Tamizaje en cáncer cervical: conocimiento de la utilidad y uso de citología cervical en México

OBJECTIVE: To identify and evaluate the predisposing factors regarding the utilization of the Pap smears in the population seen in the Cervical Cancer Screening Program in Mexico METHODS: A cross-sectional study was conducted from January 1997 through December 1998 in Mexico city. A questionnaire was applied to a total of 2,107 women of reproductive age who attended a family planning program and data was collected regarding the following topics: social-demographics, reproductive risk factors associated with cervical cancer, sexual behavior and partner history, birth control, knowledge about Pap smear' benefits, and its utilization. Statistic analysis was conducted using Student&acute;s test and non-conditional multiple logistic regression model for determining significance. RESULTS: The predisposing factors were: knowledge about Pap smear's benefits (OR=6.00, CI 95% 4.70-7.67), history of using at least two birth control methods (OR=2.38, CI 95% 1.75-3.24), previous history of vaginal infection (OR=2.18, CI 95% 1.73-2.75), sexual partner's approval of gynecological examinations (OR=1.56, CI 95% 1.07-2.29). CONCLUSIONS: Educational programs on cancer prevention in this population should include the benefits of screening tests. Pap smears for Mexican women of reproductive age are mostly offered opportunely. The previous use of health services is a determinant factor for the utilization of the Cervical Cancer Screening Program. These results show the need to strengthen health promotion programs to women at high risk of cervical cancer and their sexual partners.OBJETIVO: Identificar y evaluar los factores que predisponen a la utilización de la prueba de Papanicolaou en la población que usa el servicio del Programa Nacional de Detección Oportuna de Cáncer en México. MÉTODOS: Se realizó un estudio del tipo transversal de enero de 1997 a diciembre de 1998, en la Ciudad de México; se incluyeron a 2.107 mujeres en edad reproductiva que acudieron a un servicio de planificación familiar, las cuáles respondieron a un cuestionario con preguntas sobre características: sociodemográficas, factores de riesgo reproductivo asociados a cáncer cervical, historia de vida sexual, uso de métodos anticonceptivos, conocimiento de la utilidad y utilización del Papanicolaou. Para el análisis de los datos se construyeron modelos multivariados de regresión logística no condicional. RESULTADOS: Los predisponentes de utilización del programa de detección oportuna de cáncer en esta población fueron: el conocimiento de la utilidad del Papanicolaou incrementó en seis veces más la posibilidad de utilización (IC 95% 4,70-7,67); el antecedente de utilización de dos o más métodos de planificación familiar (OR=2,38; IC 95% 1,75-3,24); el antecedente de historia de infección vaginal (OR=2,18; IC 95% 1,73-2,75), y la aceptación del esposo para la realización de exploraciones ginecológicas (OR=1,56; IC 95% 1,07-2,29). CONCLUSIONES: La implementación de programas educativos en la prevención de cáncer, deberán incluir la utilidad de las pruebas de detección. En México, en mujeres en edad reproductiva utilización de la prueba de Papanicolaou se ofrece predominantemente en forma oportunista, por lo que el antecedente de utilización de los Servicios de Salud es un determinante para la utilización del Programa de Detección Oportuna de Cáncer Cervical. Estos resultados muestran la necesidad de ampliar la promoción a la salud de este programa a las mujeres de alto riesgo, incluyendo a sus parejas sexuales