Abstract: Objective: To discuss cervical cancer (CC), Human Papilloma Virus (HPV), CC control program and propose alternatives for Chile. Materials and methods: We analyzed the national program of CC 1966-2015 and the clinical CC guideline 2015-2020; HPV prevalence in women and in cases of CC; HPV infection and serology; the self-vaginal sample; the accuracy and cost-effectiveness of screening with HPV versus Papanicolaou, and triage options among HPV-AR positives. Results: 600 women die of CC each year in Chile, mainly from low resources. Papanicolaou coverage is <70%; Papanicolaou sensitivity is much lower than HPV test. Change from Papanicolaou to HPV test is cost-effective. Since 2015, girls under 13 have been vaccinated against HPV. Conclusions: There are the technical and economic conditions for a substantial improvement of CC in Chile: replacement of the Papanicolaou by HPV; screening every five years, with the option of self-sampling, and triage based on HPV 16/18 or Papanicolaou typing.

Resumen: Objetivos: Discutir el cáncer cervicouterino (CC), el virus del papiloma humano (VPH), el programa de control del CC y proponer alternativas para Chile. Material y métodos: Se analiza el programa nacional del CC 1966-2015 y la guía clínica 2015-2020, la prevalencia de VPH en mujeres y en casos de CC; la infección y serología de VPH; la autotoma; la precisión y rentabilidad del tamizaje con VPH contra el Papanicolaou y las opciones de triaje en VPH AR positivas. Resultados: En Chile mueren 600 mujeres (principalmente de bajos recursos) al año por CC. La cobertura del Papanicolaou es < 70%, sensibilidad muy inferior al test de VPH, por lo que el cambio es rentable. Desde 2015 se vacuna contra VPH a niñas menores de 13 años. Conclusiones: Las condiciones técnicas y económicas existen en Chile para lograr una mejoría sustancial del CC: se sugiere el reemplazo del Papanicolaou por el examen de VPH; tamizaje cada cinco años con opción de autotoma; triaje con base en la tipificación de VPH 16/18 o Papanicolaou.

Abstract: Objective: To discuss cervical cancer (CC), Human Papilloma Virus (HPV), CC control program and propose alternatives for Chile. Materials and methods: We analyzed the national program of CC 1966-2015 and the clinical CC guideline 2015-2020; HPV prevalence in women and in cases of CC; HPV infection and serology; the self-vaginal sample; the accuracy and cost-effectiveness of screening with HPV versus Papanicolaou, and triage options among HPV-AR positives. Results: 600 women die of CC each year in Chile, mainly from low resources. Papanicolaou coverage is <70%; Papanicolaou sensitivity is much lower than HPV test. Change from Papanicolaou to HPV test is cost-effective. Since 2015, girls under 13 have been vaccinated against HPV. Conclusions: There are the technical and economic conditions for a substantial improvement of CC in Chile: replacement of the Papanicolaou by HPV; screening every five years, with the option of self-sampling, and triage based on HPV 16/18 or Papanicolaou typing.

Resumen: Objetivos: Discutir el cáncer cervicouterino (CC), el virus del papiloma humano (VPH), el programa de control del CC y proponer alternativas para Chile. Material y métodos: Se analiza el programa nacional del CC 1966-2015 y la guía clínica 2015-2020, la prevalencia de VPH en mujeres y en casos de CC; la infección y serología de VPH; la autotoma; la precisión y rentabilidad del tamizaje con VPH contra el Papanicolaou y las opciones de triaje en VPH AR positivas. Resultados: En Chile mueren 600 mujeres (principalmente de bajos recursos) al año por CC. La cobertura del Papanicolaou es < 70%, sensibilidad muy inferior al test de VPH, por lo que el cambio es rentable. Desde 2015 se vacuna contra VPH a niñas menores de 13 años. Conclusiones: Las condiciones técnicas y económicas existen en Chile para lograr una mejoría sustancial del CC: se sugiere el reemplazo del Papanicolaou por el examen de VPH; tamizaje cada cinco años con opción de autotoma; triaje con base en la tipificación de VPH 16/18 o Papanicolaou.

Our aim was to describe sperm parameters in residents from Northern Chile. We evaluated in 101 volunteers (18 and 30 years old) urinary and drinking water Boron levels using Inductively Coupled Plasma Mass Spectrometry; semen parameters were measured with standardized methods. Each individual was categorized in 3 levels of exposure: low (B levels in urine 2.94 mgL-1 or tap water 3.0 mgL-1), medium (urinary B between 2.95-7.4 mgL-1 and B in tap water with 3.0-7.0 mgL-1) and high (urinary B > 7.4 mgL-1 or tap water > 7.0 mgL-1). We found no significant differences among groups by pH, sperm concentration (45.1; 48.2 and 38 million/mL), motility 1th hour (38.1; 40.0 and 45.5 %) and vitality 1th hour (88.6; 88.0 and 76.9 %) respectively. Abnormal morphology was significant different (83.3; 90 and 83 %). Young men exposed to B in drinking water present sperm variations associated with the level of exposure. Most of these changes are positive at intermediate levels of B. For the highest exposures were observed negative changes in sperm morphology, concentration, motility and vitality, all relevant parameters of fertility. Beneficial effect is observed at medium exposure, like a "U curve".

El objetivo de este trabajo fue describir los parámetros espermáticos en residentes del norte de Chile. Se evaluaron en 101 voluntarios (18 y 30 años), los niveles urinarios y de agua potable de boro, usando "Inductively Coupled Plasma Mass Spectrometry". Los parámetros del semen se midieron con métodos estandarizados. Cada individuo se clasificó en 3 niveles de exposición: bajo (niveles B en la orina 2,94 mgL-1 o agua potable 3,0 mgL-1), medio (B urinario entre 2,95-7,4 mgL-1 y B en agua de beber con 3,0- 7,0 mgL-1) y alto (B urinario >7,4 mgL-1 o agua potable > 7,0 mgL-1). No se encontraron diferencias significativas entre los grupos por pH, concentración de espermatozoides (45,1; 48,2 y 38 millones/mL), motilidad a 1 hora (38,1; 40,0 y 45,5%) y vitalidad 1 hora (88,6; 88,0 y 76,9%) respectivamente. La morfología anormal fue significativamente diferente (83,3; 90 y 83%). Los hombres jóvenes expuestos a B en el agua potable presentan variaciones espermáticas asociadas con el nivel de exposición. La mayoría de estos cambios son positivos en niveles intermedios de B. Para las exposiciones más altas se observaron cambios negativos en la morfología, concentración, motilidad y vitalidad del esperma, parámetros relevantes de la fertilidad. Un efecto beneficioso se observa en la exposición media, como una "curva U".

Background: Molecular techniques for human papillomavirus (HPV) detection have a good performance as screening tests and could be included in cervical cancer early detection programs. We conducted a population-based trial comparing HPV detection and Papanicolaou as primary screening tests, in a public health service in Santiago, Chile. Aim: To describe the experience of implementing this new molecular test and present the main results of the study. Material and Methods: Women aged 25 to 64 enrolled in three public health centers were invited to participate. In all women, samples were collected for Papanicolaou and HPV DNA testing, and naked-eye visual inspection of the cervix with acetic acid was performed. Women with any positive screening test were referred to the local area hospital for diagnostic confirmation with colposcopy and biopsy of suspicious lesions. Results: Screening results were obtained for 8265 women, of whom 931 (11.3%) were positive to any test. The prevalence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was 1.1%; nine women had invasive cervical cancer. Sensitivities for the detection of CIN2+ were 22.1% (95% confidence interval (CI) 16.4-29.2) for Papanicolaou and 92.7% (95% CI 84.4-96.8) for HPV testing; specificities were 98.9% (95% CI 98.7-99.0) and 92.0% (95% CI 91.4-92.6) respectively. Conclusion: This experience showed that the implementation of a molecular test for cervical cancer screening is not a major challenge in Chile: it was well accepted by both the health team and the participants, and it may improve the effectiveness of the screening program.

INTRODUCTION: The South American country Chile now boasts a life expectancy of over 80 years. As a consequence, Chile now faces the increasing social and economic burden of cancer and must implement political policy to deliver equitable cancer care. Hindering the development of a national cancer policy is the lack of comprehensive analysis of cancer infrastructure and economic impact. OBJECTIVES: Evaluate existing cancer policy, the extent of national investigation and the socio-economic impact of cancer to deliver guidelines for the framing of an equitable national cancer policy. METHODS: Burden, research and care-policy systems were assessed by triangulating objective system metrics -epidemiological, economic, etc. - with political and policy analysis. Analysis of the literature and governmental databases was performed. The oncology community was interviewed and surveyed. RESULTS: Chile utilizes 1% of its gross domestic product on cancer care and treatment. We estimate that the economic impact as measured in Disability Adjusted Life Years to be US$ 3.5 billion. Persistent inequalities still occur in cancer distribution and treatment. A high quality cancer research community is expanding, however, insufficient funding is directed towards disproportionally prevalent stomach, lung and gallbladder cancers. CONCLUSIONS: Chile has a rapidly ageing population wherein 40% smoke, 67% are overweight and 18% abuse alcohol, and thus the corresponding burden of cancer will have a negative impact on an affordable health care system. We conclude that the Chilean government must develop a national cancer strategy, which the authors outline herein and believe is essential to permit equitable cancer care for the country.

Introduction and objectives: Plasma lipid levels in children and adolescents are evaluated with international references. The objective was to describe them in Chilean students, to compare them with the most used reference (Lipids Research Clinics Program) and the cut-off points recommended in 2011. Methods: Cross-sectional study in 3325 children, 10 to 14 years of age. Anthropometry and auto-report of pubertal development were performed. A 12 hours fast blood sample was taken to measure total (TC), high-density lipoprotein cholesterol (HDLC) and triglycerides (TG). Low-density lipoprotein cholesterol (LDLC) was calculated with Friedewald formula. Variables were described, Hochberg test for multiple comparisons and stepwise lineal regression were applied. The degree of agreement between local percentiles and the two international references was studied. Results: We studied 3,063 children, 11.4 ± 0.9 years old, 53% girls, 20.9% pre-pubertal, 22.6% had overweight, and 15.8% obesity. Averages: TC: 159.2 ± 28.3, HDLC: 51.9 ± 12.1, LDLC: 89.0 ± 31.5 and TG: 93.2 ± 60 mg/dL. Boys had higher HDLC: 53.3 ± 12.2 vs. 50.6 ± 11.8 mg/dL and lower TG: 86.2 ± 58.2 vs. 99.5 ± 61.7 mg/dL than girls (p < 0,001). Influences of nutritional status, sex and age were significant. We founded high agreement with the reference for TC and LDLC, but HDLC levels were lower and TG were higher, for their cut-off points: percentiles 10th and 95th, respectively. Conclusions: Blood lipids were influenced by nutritional status, sex and age. Percentile values were comparable to the international reference except for HDLC and TG, showing a more atherogenic pattern.

Introducción: Las concentraciones de lípidos sanguíneos en niños y adolescentes se evalúan utilizando referencias internacionales. Objetivos: Describir las concentraciones de lípidos sanguíneos en una población de escolares chilenos y compararlas con la referencia más utilizada (Lipid Research Clinics Program) además de los puntos de corte recomendados en 2011. Métodos: Estudio transversal en 3.325 escolares de 10 a 14 años de edad. Se realizó antropometría, autoreporte de desarrollo puberal y medición en ayunas de colesterol total (CT), colesterol unido a lipoproteínas de alta densidad (CHDL) y triglicéridos (TG). El colesterol unido a lipoproteínas de baja densidad (CLDL) se calculó con fórmula de Friedewald. Se realizó descripción, regresión múltiple y estudio de concordancia. Resultados: Se incluyeron 3.063 niños de 11,4 ± 0,9 años de edad, 53% mujeres, 20,9% pre-púberes; 22,6% con sobrepeso y 15,8% con obesidad. Los promedios fueron: CT: 159,2 ± 28,3, CHDL: 51,9 ± 12,1, LDL: 89,0 ± 31,5 y TG: 93,2 ± 60 mg/dL. Los hombres tuvieron mayor CHDL: 53,3 ± 12,2 vs 50,6 ± 11,8 mg/dL y menor TG: 86,2 ± 58,2 vs 99,5 ± 61,7 mg/dL que las mujeres (p < 0,001). Con regresión múltiple se encontró influencia del estado nutricional y edad en todos los lípidos y del sexo en la mayoría. Comparados con la referencia hubo concordancia en CT y CLDL, pero los niños chilenos presentaron mayores niveles de TG sobre el percentil 50 y menores niveles de CHDL bajo percentil 50. Conclusiones: Las concentraciones de lípidos sanguíneos estuvieron influidas por el estado nutricional, edad y sexo. En comparación a la referencia, se encontró un patrón de mayor riesgo cardiovascular en los niños chilenos.

OBJECTIVE: To evaluate acceptance, preference and compliance with referral of vaginal self-sampling for the detection of Human papillomavirus (HPV) among women non-adherent to Papanicolaou (Pap) screening in Santiago, Chile. MATERIALS AND METHODS: Using multistage sampling we identified women aged 30-64 years who reported not receiving a Pap test in the previous three years and offered them Pap testing at the health center or vaginal self-sampling for HPV testing at home. Self-collected samples were analyzed with hybrid capture. All HPV+ women were referred for colposcopy, biopsy and treatment when needed. RESULTS: 1 254 eligible women were contacted; 86.5% performed self-sampling and 8.1% refused; 124 women were HPV+ (11.4%: 95%CI 9.6-13.5) of whom 85.5% attended colposcopy; 12 had CIN2+ (1.1%: 95 %CI 0.5-1.7). CONCLUSION: HPV vaginal self-sampling can be easily implemented in Chile and could improve coverage, successfully reaching women who drop out of the screening program.

OBJETIVO: Evaluar la aceptación, preferencia y adherencia a seguimiento de la autotoma vaginal para detección del virus del papiloma humano (VPH) en mujeres inasistentes a Papanicolaou (Pap) en Santiago, Chile. MATERIAL Y MÉTODOS: Mediante un muestreo polietápico se identificaron mujeres entre 30 y 64 años inasistentes a Pap por < 3 años, invitándolas a realizarse un Pap en su centro de salud o una autotoma vaginal a domicilio. Las muestras fueron analizadas con captura de híbridos. Las mujeres VPH+ fueron referidas a colposcopía, biopsia y tratamiento en caso necesario. RESULTADOS: 1 254 mujeres elegibles fueron contactadas; 86.5% aceptó la autotoma vaginal y 8.1% la rechazó; 124 mujeres resultaron VPH+ (11.4%: IC95% 9.6-13.5) de las que 85.5% asistió a colposcopía; 12 tenían CIN2+ (1.1%: IC95% 0.5-1.7). CONCLUSIÓN: La autotoma vaginal para detección de VPH es implementable en Chile y su utilización podría mejorar la cobertura del programa rescatando a mujeres inasistentes.

OBJECTIVE: To evaluate acceptance, preference and compliance with referral of vaginal self-sampling for the detection of Human papillomavirus (HPV) among women non-adherent to Papanicolaou (Pap) screening in Santiago, Chile. MATERIALS AND METHODS: Using multistage sampling we identified women aged 30-64 years who reported not receiving a Pap test in the previous three years and offered them Pap testing at the health center or vaginal self-sampling for HPV testing at home. Self-collected samples were analyzed with hybrid capture. All HPV+ women were referred for colposcopy, biopsy and treatment when needed. RESULTS: 1 254 eligible women were contacted; 86.5% performed self-sampling and 8.1% refused; 124 women were HPV+ (11.4%: 95%CI 9.6-13.5) of whom 85.5% attended colposcopy; 12 had CIN2+ (1.1%: 95 %CI 0.5-1.7). CONCLUSION: HPV vaginal self-sampling can be easily implemented in Chile and could improve coverage, successfully reaching women who drop out of the screening program.

OBJETIVO: Evaluar la aceptación, preferencia y adherencia a seguimiento de la autotoma vaginal para detección del virus del papiloma humano (VPH) en mujeres inasistentes a Papanicolaou (Pap) en Santiago, Chile. MATERIAL Y MÉTODOS: Mediante un muestreo polietápico se identificaron mujeres entre 30 y 64 años inasistentes a Pap por < 3 años, invitándolas a realizarse un Pap en su centro de salud o una autotoma vaginal a domicilio. Las muestras fueron analizadas con captura de híbridos. Las mujeres VPH+ fueron referidas a colposcopía, biopsia y tratamiento en caso necesario. RESULTADOS: 1 254 mujeres elegibles fueron contactadas; 86.5% aceptó la autotoma vaginal y 8.1% la rechazó; 124 mujeres resultaron VPH+ (11.4%: IC95% 9.6-13.5) de las que 85.5% asistió a colposcopía; 12 tenían CIN2+ (1.1%: IC95% 0.5-1.7). CONCLUSIÓN: La autotoma vaginal para detección de VPH es implementable en Chile y su utilización podría mejorar la cobertura del programa rescatando a mujeres inasistentes.

Cervical cancer continues to be a significant health problem in Latin America. The use of conventional cytology to detect precancerous cervical lesions has had almost no major impact on reducing cervical cancer incidence and mortality rates, which are still high in the region. The availability of new screening tools to detect precancerous lesions provide great opportunities for cervical cancer prevention in the region, as do highly efficacious HPV vaccines able to prevent nearly all lesions associated with HPV-16 and -18 when applied before viral exposure. This paper summarizes the scientific evidence and regional experiences related to: i) the use of HPV testing and visual inspection after the application of acetic acid (VIA) in primary screening and ii) the implementation of adolescent HPV vaccination programs. Finally, we outline a number of recommendations for different resource settings. The feasibility of implementing successful and sustainable national cervical cancer prevention programs in Latin American countries in the region will depend on health priorities and the availability of infrastructure and health personnel-as determined by rigorous local situational analysis.

El cáncer de cuello uterino sigue siendo un problema de salud pública en Latinoamérica. El uso de la citología para la detección de lesiones pre-cancerosas no ha tenido mayor impacto en las tasas de incidencia y mortalidad, que aún se mantienen altas en la región. La disponibilidad de nuevas técnicas de tamizaje para la detección de lesiones pre-cancerosas y de vacunas altamente eficaces que previenen casi todas las lesiones relacionadas con VPH-16 y VPH-18 en mujeres no expuestas previamente al virus representan una gran oportunidad para la prevención del cáncer de cuello uterino en la región. En este manuscrito resumimos la evidencia científica y la experiencia de la región en i) el uso de pruebas de VPH y de la inspección visual después del ácido acético (IVAA) en tamizaje primario, y ii) la implementación de programas de vacunación en adolescentes. Finalmente enumeramos una serie de recomendaciones adecuadas para distintos escenarios. La factibilidad de implementar un programa nacional de prevención de cáncer de cuello uterino exitoso y sostenible en países latinoamericanos dependerá de las prioridades de salud, la infraestructura y personal de salud disponible, determinadas luego de un riguroso análisis situacional local.

Cervical cancer continues to be a significant health problem in Latin America. The use of conventional cytology to detect precancerous cervical lesions has had almost no major impact on reducing cervical cancer incidence and mortality rates, which are still high in the region. The availability of new screening tools to detect precancerous lesions provide great opportunities for cervical cancer prevention in the region, as do highly efficacious HPV vaccines able to prevent nearly all lesions associated with HPV-16 and -18 when applied before viral exposure. This paper summarizes the scientific evidence and regional experiences related to: i) the use of HPV testing and visual inspection after the application of acetic acid (VIA) in primary screening and ii) the implementation of adolescent HPV vaccination programs. Finally, we outline a number of recommendations for different resource settings. The feasibility of implementing successful and sustainable national cervical cancer prevention programs in Latin American countries in the region will depend on health priorities and the availability of infrastructure and health personnel-as determined by rigorous local situational analysis.

El cáncer de cuello uterino sigue siendo un problema de salud pública en Latinoamérica. El uso de la citología para la detección de lesiones pre-cancerosas no ha tenido mayor impacto en las tasas de incidencia y mortalidad, que aún se mantienen altas en la región. La disponibilidad de nuevas técnicas de tamizaje para la detección de lesiones pre-cancerosas y de vacunas altamente eficaces que previenen casi todas las lesiones relacionadas con VPH-16 y VPH-18 en mujeres no expuestas previamente al virus representan una gran oportunidad para la prevención del cáncer de cuello uterino en la región. En este manuscrito resumimos la evidencia científica y la experiencia de la región en i) el uso de pruebas de VPH y de la inspección visual después del ácido acético (IVAA) en tamizaje primario, y ii) la implementación de programas de vacunación en adolescentes. Finalmente enumeramos una serie de recomendaciones adecuadas para distintos escenarios. La factibilidad de implementar un programa nacional de prevención de cáncer de cuello uterino exitoso y sostenible en países latinoamericanos dependerá de las prioridades de salud, la infraestructura y personal de salud disponible, determinadas luego de un riguroso análisis situacional local.

Background: Semen analysis is one of the parameters used to predict male fertility. Semen can be altered by environmental pollutants; therefore it could be used as a biological marker of exposure in contaminated areas. Aim: To analyze the spermogram values in a sample of healthy young males, residing in Arica, Chile. Material and methods: One hundred and two healthy university students volunteers aged 18 to 30 years answered a questionnaire about fertility, habits and andrologic diseases and provided a semen sample. Within three hours after ejaculation, semen volume, pH, sperm concentration, motility and morphology were analyzed. Results: Six percent of volunteers had offspring, 1% declared to be infertile, 32% smoked and 78% con-sumed alcohol. Semen pH was 7.6 ± 0.5, volume, 2.9 ± 1.6 ml, sperm concentration, 62.8 ± 62.3 x 10(6)/ml, normal morphology, 15.0 ± 7.9%, overall motility, 42.2 ± 23.2 % and grade A motility, 19.2 ± 18.6%. The percentage of subjects that had normal semen values was 82% for total sperm count, 76% for sperm concentration, 72% for volume, 64% for vitality, 63% for pH, 57% for morphology, 38% for overall motility and 26% for grade A motility. Conclusions: This sample of healthy young males had a normal sperm count in comparison with international reports. However it is necessary to characterize the spermogram in uncontaminated areas of Chile to ensure that our results are within the expected values for the country.

Background: Chile has the highest gallbladder cancer (GBC) death rate world-wide, affecting mainly Southern areas of the country. Aim: To compare the survival of GBC patients treated in hospitals located in areas with low and high risk for GBC. Material and Methods: Medical records of all patients with GBC admitted to one public hospital located in southern Chile, a public hospital and a private clinic, both located in Metropolitan Santiago, were reviewed. Cases were analyzed by age, sex, stage at diagnosis, ethnicity, socioeconomic status (SES) and rural residence. Survival was calculated using Kaplan Meier method. Results: A total of 598 cases (469 women), were analyzed. No differences in age or sex among hospitals were detected. At the moment of diagnosis, 75, 50 and 44% of cases from the hospital in southern Chile, the public hospital in Santiago and the private clinic in Santiago, were in stage IV, respectively. Five years survival was lower in the public hospital in southern Chile than in the public hospital in Santiago (10.7 and 14.4% respectively, p < 0.05) but not statistically different from the figure at the private clinic in Santiago (13.0%). However, when adjusting for stage at the moment of diagnosis, no difference in survival between the three hospitals, was found. The median days of survival were 1,559, 188, 70 and 69 for stages I, II, III and IV respectively. Conclusions: GBC mortality is high. The stage at the moment of diagnosis is only significant predictor of survival.

Background: There are several diagnostic criteria for Metabolic Syndrome (MS) defnition. Aim: To study their application in the Chilean general adult population. Material and Methods: We analyzed data from a random sub sample of 1.833 adults aged 17 years and older surveyed during the First Chilean National Health Survey conducted in 2003. The prevalence of MS was estimated using the update Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program (NCEP) and the International Diabetes Federation (IDF 2005) criteria. The distribution of MS was analyzed according to age, gender, educational level, geographic area, obesity and sedentary lifestyle. Results: The overall prevalence of MS was 31.6% (95% CI 28.5-34.9) and 36.8% (95% CI 33.5-40.3), according to update ATPIII-NCEP and IDF criteria respectively. Both criteria had a 90% concordance. Demographic and socioeconomic distribution was similar for both criteria. The prevalence of high blood pressure, high fasting glucose, and low HDL cholesterol (MS components) were: 46, 22 and 53% respectively. The prevalence of abnormal waist circumference was 30 and 59% according to update ATPIII-NCEP and IDF criteria, respectively. Using update ATPIII-NCEP criteria, the gender, age and educational level adjusted odds ratio (OR) for having MS was 9.59 (95% IC 6.8- 13.6) for obese subjects compared with normal weight subjects and 2.14 (95% IC 1.3-3.7) for sedentary subjects compared with non sedentary. Conclusions: There was a 90% agreement between update ATPIII-NCEP and IDF criteria for the diagnosis of MS. The overall prevalence of MS in this population was 32% usuing update ATPIII-NCEP criteria, with higher prevalence among obese and sedentary subjects.

Background: Cervical cancer is the third cause of cancer death among Chilean women, affecting mainly women from low socioeconomic status. Aim: To determine main risk factors (RF) including human papilomavirus (HPV) types associated with abnormal cervical cytology (Atypical Squamous Cells of Undetermined Significance or ASCUS) among Chilean women from low socioeconomic status in Santiago, Chile. Material and Methods: A random population based sample of616 women from La Pintana (a low-income district in Santiago) participated in 2001 in a HPV prevalence study and were re-evaluated in 2006 through a risk factors questionnaire, Papanicolaou test and DNA detection for HPV. The Papanicolaou test was analyzed in Santiago and HPV analysis (PCR_GP5+/GP6+) was conducted in Vrije University, Amsterdam. Cases included 42 women with cervical lesions and controls included 574 women with normal cytology during the period 2001-2006. Logistic regression with uni and multivariate analysis was performed to identify RF for cervical lesions. Results: During the study period, there was a significant increase in the proportion of single women, from 8.3 to 14.8% (p < 0.05), of women with 3 or more sexual partners from 8.9 to 13.3 and of women high risk HPV, from 9.1 to 14.3%. The proportion of abnormal Papanicolaou tests remained stable (3.08 and 3.9% > ASCUS). High risk HPV was the most significant factor associated with cervical lesions (odds ratio (OR) = 9.695%> confidence intervals (CI) = 4.4-21.1) followed by oral contraceptive use (OR = 2.58 95%> CI= 1.2-5.7). Among women infected by high risk HPV, the use of oral contraceptives was a risk factor while compliance with screening was protective for cervical lesions. Conclusions: From 2001 to 2006, there was an increase in the proportion of women with high-risk HPV infections.

Unit non-response is a growing problem in sample surveys that can bias survey estimates if respondents and non-respondents differ systematically. Objetives: To compare the results of two nonresponse adjustment methods: field substitution and weighting nonresponse adjustment based on response propensity. Methods: Field substitution and response propensity weights are used to adjust for non-response and their effect on the prevalence of six survey outcomes is compared. Results Although significant differences are found between respondents and non-respondents, only slight changes on prevalence estimates are observed after adjustment, with both techniques showing similar results. In the sole case of smoking, substitution seems to have further biased survey estimates. Conclusions: Our results suggest that when there is information available for both respondents and non-respondents, or if a careful sample substitution process is performed, weighting adjustments based on response propensity and field substitution produce comparable results on prevalence estimates.

La no respuesta es un problema creciente en encuestas poblacionales que puede ser causa de sesgo de no-respuesta cuando respondedores y no respondedores difieren sistemáticamente. Objetivo: Comparar los resultados obtenidos mediante dos técnicas de corrección para el sesgo de no-respuesta: sustitución muestral y pesos de no respuesta obtenidos mediante propensión a responder. Métodos: Se comparan los efectos de la sustitución muestral semicontrolada y el uso de pesos de ajuste obtenidos mediante la propensión a responder sobre seis resultados de una encuesta de salud. Resultados: A pesar de las diferencias significativas entre respondedores y no respondedores, mediante la corrección las prevalencias estimadas sólo cambian levemente, dando ambas técnicas de ajuste resultados similares. Sólo en el caso del tabaquismo, la sustitución muestral parece haber aumentado el sesgo de la estimación. Conclusiones: Nuestros resultados sugieren que tanto mediante un procedimiento de sustitución muestral semicontrolada, como a través del ajuste estadístico de la no respuesta mediante la propensión a responder, se obtienen estimaciones de prevalencias corregidas similares.