Claudio Vargas - Academia.edu (original) (raw)
Papers by Claudio Vargas
Revista Chilena De Cirugia, Aug 1, 2015
Hospital readmission rates in complex colorrectal surgery background: non programmed hospital rea... more Hospital readmission rates in complex colorrectal surgery background: non programmed hospital readmission rates are a quality indicator of colorectal surgery. aim: To analyze the causes of readmission of patients subjected to surgical procedures including intestinal anastomoses. material and methods: Analysis of a database of patients subjected to elective intestinal anastomoses in a period of 10 years. All non-programmed readmissions that occurred within 30 days after patient discharge were analyzed. results: Overall non-programmed readmission rate was 7% and it was due to medical causes in 55% of patients. nine percent of readmitted patients required a new surgical intervention. The figure among patients readmitted due to surgical causes, was 20%. Sixty one percent of patients were admitted at less than six days after discharge and 84% at less than 10 days. A non-programmed readmission duplicated the total hospitalization lapse and triplicated the rates of new surgical procedures. conclusions: In this series of patients, the only predictor of a non-programmed readmission was the need for reoperation during the first admission.
PLOS ONE
Personal protective measures such use of face masks, hand washing and physical distancing have pr... more Personal protective measures such use of face masks, hand washing and physical distancing have proven to be effective in controlling the spread of the Covid-19 pandemic. However, adherence to these measures may have been relaxed over time. The objective of this work is to assess the change in adherence to these measures and to find factors that explain the change For this purpose, we conducted a survey in the Metropolitan Region of Chile in which we asked the adherence to these measures in August-September 2021 and retrospectively for 2020. With the answers obtained we fit a logistic regression model in which the response variable is the relaxation of each of the self-care preventive actions. The explanatory variables used are socio-demographic characteristics such as the age, sex, income, and vaccination status of the respondents. The results obtained show that there has been a significant decrease in adherence to the three personal protection measures in the Metropolitan Region of...
Statistical Methods in Medical Research, 2021
A key hypothesis in epidemiological studies is that time to disease exposure provides relevant in... more A key hypothesis in epidemiological studies is that time to disease exposure provides relevant information to be considered in statistical models. However, the initiation time of a particular condition is usually unknown. Therefore, we developed a multiple imputation methodology for the age at onset of a particular condition, which is supported by incidence data from different sources of information. We introduced and illustrated such a methodology using simulated data in order to examine the performance of our proposal. Then, we analyzed the association of gallstones and fatty liver disease in the Maule Cohort, a Chilean study of chronic diseases, using participants’ risk factors and six sources of information for the imputation of the age-occurrence of gallstones. Simulated studies showed that an increase in the proportion of imputed data does not affect the quality of the estimated coefficients associated with fully observed variables, while the imputed variable slowly reduces it...
Journal of the Neurological Sciences, 2015
To evaluate the value of HBOT for Ischemic Cerebral Stroke, after at least one month from the ons... more To evaluate the value of HBOT for Ischemic Cerebral Stroke, after at least one month from the onset. Material and methods: This prospective study was conducted on 80 patients (aged 40-70 years) with ischemic cerebral stroke at least one month prior to inclusion. All patients signed a written informed consent.Thorough history taking, physical and neurological examination, and neuroimaging studies of the brain were carried out.Patients were randomly assigned to either one of two groups; A study group (n = 50) received 40 HBOT sessions (5 sessions per week) in addition to conventional therapy, and control group (n = 30) receiving only conventional therapy. All patients were subjected to thorough history taking, neurological examination and assessment for fitness of HBOT.Neurological Functions were evaluated by modified Ashworth scale, and modified Rankin scale at baseline, after 4 and 8 weeks of inclusion. Results: There was a significant difference in the mean change of Ashworth score from baseline to 4th week of the studied patients compared to the Control (p b 0.001), and from baseline to 8th week of the studies patients compared to the control group (p b 0.001) There was a significant difference in the mean change of the modified Rankin score from baseline to 4th week of the studied patients compared to the control (p b 0.001) and from baseline to 8th week of the studied patients compared to the control (p b 0.001) Conclusion: Both groups attained clinically significant improvement, however more apparent in the study group compared to the baseline, and to correlate this to the presence of HBOT, a further study of patients after attaining a state of Neurological stability is recommended.
Revista chilena de cirugía, 2013
Prognostic value of pathological response to chemo radiotherapy of locally advanced low rectal ca... more Prognostic value of pathological response to chemo radiotherapy of locally advanced low rectal cancer Background: Preoperative chemo radiotherapy improves the prognosis of locally advanced low rectal cancer and induces a pathological response in the tumor, which may have prognostic value. Aim: To assess the results of rectal cancer treatment according to the degree of pathological response of the tumor after chemo radiotherapy. Patients and Methods: All patients with a locally advanced rectal cancer located within 11 cm of the rectal margin, subjected to preoperative chemo radiotherapy followed by surgical treatment in a period of 13 years, were included. Pathological response was classified as complete, intermediate and poor. The tumor was staged according to TNM 2002 classification. Survival was analyzed with Kaplan Meier curves and Cox regression. Results: Patients were followed for a mean of 50 months (range 18-156). Exclusive and global local relapse was observed in 3 and 9.6% of patients, respectively. Pathological response was complete in 13 patients (none died), intermediate in 23 (three died) and poor in 68 (22 died). Global five years survival was 74%. There was a concordance of 0.64 between survival and pathological response. The concordance between survival and TNM classification was 0.69. Conclusions: The pathological response of the tumor to chemo radiotherapy has a good concordance with prognosis, although it is not superior to the final pathological status.
Background Several studies have shown that in Chile income inequality is relevant in explaining i... more Background Several studies have shown that in Chile income inequality is relevant in explaining inequities in health outcomes. The COVID-19 pandemic has also had a non-neutral impact, with higher mortality rates in municipalities with lower socioeconomic status. Methods We study inequity in mortality based on Potential Years of Life Lost (PYLL) in 34 urban municipalities of the Metropolitan Region (Greater Santiago) and analyze its evolution between 2018 and 2021 and by COVID-19 waves. In order to compare the results obtained for PYLL, we also computed the mortality rates adjusted by direct standardization. In addition, we used the concentration index to measure the health inequalities between municipalities. Results In the first year of the pandemic, the absolute PYLL and the crude mortality rate for all causes of death showed an increase of 13.6% and 19.8%, respectively. Moreover, 409,086 years of life were prematurely lost in 2020, one-fifth of them due to COVID-19. The concentra...
International Journal of Environmental Research and Public Health, 2021
The identification of COVID-19 waves is a matter of the utmost importance, both for research and ... more The identification of COVID-19 waves is a matter of the utmost importance, both for research and decision making. This study uses COVID-19 information from the 52 municipalities of the Metropolitan Region, Chile, and presents a quantitative method—based on weekly accumulated incidence rates—to define COVID-19 waves. We explore three different criteria to define the duration of a wave, and performed a sensitivity analysis using multivariate linear models to show their commonalities and differences. The results show that, compared to a benchmark definition (a 100-day wave), the estimations using longer periods of study are worse in terms of the model’s overall fit (adjusted R2). The article shows that defining a COVID-19 wave is not necessarily simple, and has consequences when performing data analysis. The results highlight the need to adopt well-defined and well-justified definitions for COVID-19 waves, since these methodological choices can have an impact in research and policy mak...
International Journal of Environmental Research and Public Health
The identification of COVID-19 waves is a matter of the utmost importance, both for research and ... more The identification of COVID-19 waves is a matter of the utmost importance, both for research and decision making. This study uses COVID-19 information from the 52 municipalities of the Metropolitan Region, Chile, and presents a quantitative method—based on weekly accumulated incidence rates—to define COVID-19 waves. We explore three different criteria to define the duration of a wave, and performed a sensitivity analysis using multivariate linear models to show their commonalities and differences. The results show that, compared to a benchmark definition (a 100-day wave), the estimations using longer periods of study are worse in terms of the model’s overall fit (adjusted R2). The article shows that defining a COVID-19 wave is not necessarily simple, and has consequences when performing data analysis. The results highlight the need to adopt well-defined and well-justified definitions for COVID-19 waves, since these methodological choices can have an impact in research and policy mak...
International Journal of Environmental Research and Public Health
The identification of COVID-19 waves is a matter of the utmost importance, both for research and ... more The identification of COVID-19 waves is a matter of the utmost importance, both for research and decision making. This study uses COVID-19 information from the 52 municipalities of the Metropolitan Region, Chile, and presents a quantitative method—based on weekly accumulated incidence rates—to define COVID-19 waves. We explore three different criteria to define the duration of a wave, and performed a sensitivity analysis using multivariate linear models to show their commonalities and differences. The results show that, compared to a benchmark definition (a 100-day wave), the estimations using longer periods of study are worse in terms of the model’s overall fit (adjusted R2). The article shows that defining a COVID-19 wave is not necessarily simple, and has consequences when performing data analysis. The results highlight the need to adopt well-defined and well-justified definitions for COVID-19 waves, since these methodological choices can have an impact in research and policy mak...
International Journal of Epidemiology
Pharmacoepidemiology and Drug Safety
Revista médica de Chile
Effectiveness and tolerability of low volume bowel cleansing polyethylene glycol solution for col... more Effectiveness and tolerability of low volume bowel cleansing polyethylene glycol solution for colonoscopy Background: A successful colonoscopy depends, among other factors, on a proper colon cleansing. This variable also affects the acceptance of the patient to carry out the study. Aim: To analyze the efficacy and tolerability of a low volume polyethylene glycol formulation (2 liters), compared to the conventional presentation of 4 liters. Material and Methods: Patients referred for a colonoscopy were randomly divided to receive either two or four liter of polyethylene glycol as bowel cleansing, which was assessed using the Boston score. Raters of the latter were blinded to the volume of polyethylene glycol that the patients used. Results: Seventy-four patients participated in the study. Subjects who received a 4 liters preparation had an average Boston score of 7.78, versus 8.16 for patients who received a volume of 2 liters (p = 0.267). No significant differences in tolerability were observed between both groups. No significant differences in the efficacy and tolerability between a conventional or a reduced volume of polyethylene glycol solution for the preparation of a colonoscopy were observed. These findings may be especially important for subgroups of patients with difficulties for oral administration of fluids. (Rev Med Chile 2019; 147: 977-982)
The American journal of tropical medicine and hygiene, Jan 25, 2018
From 1975 to 1983, a large epidemic of typhoid fever (TF) affected the metropolitan region (MR) o... more From 1975 to 1983, a large epidemic of typhoid fever (TF) affected the metropolitan region (MR) of Chile (incidence rate [IR] of 219.6 per 10 in 1983). In 1983-1984, interventions were implemented focusing on person-to-person transmission (vaccination, food handlers' control, and mass communication) and regulations to control irrigation waters containing fecal contaminates. In 1991, a second intervention was quickly implemented to avoid the cholera epidemic-affecting neighboring countries (total prohibition of growing or selling crops in the MR). We explored the potential impact of these interventions on the epidemic. We created a yearly database of the MR TF cases, population, and contextual factors of TF from 1969 to 2012. We first analyzed the epidemic (Joinpoint regression), identified predictors of TF (Poisson multiple regression), and then analyzed the effect of the interventions (interrupted time series model). The main predictor of the TF epidemic was the rate of unemplo...
Revista Medica De Chile, May 1, 2014
procedencia indígena como factores de riesgo de problemas nutricionales de los niños que ingresan... more procedencia indígena como factores de riesgo de problemas nutricionales de los niños que ingresan a la escuela. Salud Publica Mex 2009;51:187-193.
Revista Chilena de Pediatría, 2015
To analyse the outcomes of births and anthropometric measurements at birth of children born betwe... more To analyse the outcomes of births and anthropometric measurements at birth of children born between 1974 and 2011 at Limache Hospital (Valparaíso, Chile). Times series were constructed of births, weight and length at birth, and low weight and length at birth. The trend was modelled with linear and logistical regressions using splines to represent breaks in the trend by decade. The series includes 17,574 births. There was an increase in births per year in the 1970s (30/year) and declines in them to 17 and 22 births/year in the 1980s and 1990s, respectively (P<.001), with no significant trend thereafter. Newborns from 2000 to 2011 weighed 266 grams more than those in the 1970s (P<.001), and have now reached a mean weight of 3,530g. Low birthweight fell from 8% in the 1970s to 1.1% after 2000. Birth length increased by 1cm in the 37 years studied, with a reduction of low birth length from 7.6% to 2.1% during the period. Live births in the Limache Hospital declined, and anthropometric measurements at birth improved in the years analysed. This information is useful in developing interventions, taking into account the possible selection biases that could distort these estimates and their interpretation.
Revista médica de Chile, 2006
Temuco (304,000 inhabitants) has high levels of air pollution, mainly due to fine particulate mat... more Temuco (304,000 inhabitants) has high levels of air pollution, mainly due to fine particulate matter of less than 10 microm (PM10). The effects of this pollution on population health have not been studied. To study the short-term effects of PM10 on daily mortality in Temuco, in Southern Chile, due to respiratory and cardiovascular causes. We followed the APHEA methodology (Air Pollution and Health European Approach) by estimating poisson multivariate regression models and controlling by trends, seasonality and meteorology. The PM10 variable was introduced after controlling by the confounders and checking by statistical adjustment and autocorrelation of errors. Mortality data was obtained from the Ministry of Health, registering age, gender, place of residence and cause of death. Cancer, respiratory and cardiovascular deaths, occurring between 1997 and 2002, were recorded for this study. There was a significant and positive association between PM10 concentration and daily mortality c...
Revista Chilena De Cirugia, Aug 1, 2015
Hospital readmission rates in complex colorrectal surgery background: non programmed hospital rea... more Hospital readmission rates in complex colorrectal surgery background: non programmed hospital readmission rates are a quality indicator of colorectal surgery. aim: To analyze the causes of readmission of patients subjected to surgical procedures including intestinal anastomoses. material and methods: Analysis of a database of patients subjected to elective intestinal anastomoses in a period of 10 years. All non-programmed readmissions that occurred within 30 days after patient discharge were analyzed. results: Overall non-programmed readmission rate was 7% and it was due to medical causes in 55% of patients. nine percent of readmitted patients required a new surgical intervention. The figure among patients readmitted due to surgical causes, was 20%. Sixty one percent of patients were admitted at less than six days after discharge and 84% at less than 10 days. A non-programmed readmission duplicated the total hospitalization lapse and triplicated the rates of new surgical procedures. conclusions: In this series of patients, the only predictor of a non-programmed readmission was the need for reoperation during the first admission.
PLOS ONE
Personal protective measures such use of face masks, hand washing and physical distancing have pr... more Personal protective measures such use of face masks, hand washing and physical distancing have proven to be effective in controlling the spread of the Covid-19 pandemic. However, adherence to these measures may have been relaxed over time. The objective of this work is to assess the change in adherence to these measures and to find factors that explain the change For this purpose, we conducted a survey in the Metropolitan Region of Chile in which we asked the adherence to these measures in August-September 2021 and retrospectively for 2020. With the answers obtained we fit a logistic regression model in which the response variable is the relaxation of each of the self-care preventive actions. The explanatory variables used are socio-demographic characteristics such as the age, sex, income, and vaccination status of the respondents. The results obtained show that there has been a significant decrease in adherence to the three personal protection measures in the Metropolitan Region of...
Statistical Methods in Medical Research, 2021
A key hypothesis in epidemiological studies is that time to disease exposure provides relevant in... more A key hypothesis in epidemiological studies is that time to disease exposure provides relevant information to be considered in statistical models. However, the initiation time of a particular condition is usually unknown. Therefore, we developed a multiple imputation methodology for the age at onset of a particular condition, which is supported by incidence data from different sources of information. We introduced and illustrated such a methodology using simulated data in order to examine the performance of our proposal. Then, we analyzed the association of gallstones and fatty liver disease in the Maule Cohort, a Chilean study of chronic diseases, using participants’ risk factors and six sources of information for the imputation of the age-occurrence of gallstones. Simulated studies showed that an increase in the proportion of imputed data does not affect the quality of the estimated coefficients associated with fully observed variables, while the imputed variable slowly reduces it...
Journal of the Neurological Sciences, 2015
To evaluate the value of HBOT for Ischemic Cerebral Stroke, after at least one month from the ons... more To evaluate the value of HBOT for Ischemic Cerebral Stroke, after at least one month from the onset. Material and methods: This prospective study was conducted on 80 patients (aged 40-70 years) with ischemic cerebral stroke at least one month prior to inclusion. All patients signed a written informed consent.Thorough history taking, physical and neurological examination, and neuroimaging studies of the brain were carried out.Patients were randomly assigned to either one of two groups; A study group (n = 50) received 40 HBOT sessions (5 sessions per week) in addition to conventional therapy, and control group (n = 30) receiving only conventional therapy. All patients were subjected to thorough history taking, neurological examination and assessment for fitness of HBOT.Neurological Functions were evaluated by modified Ashworth scale, and modified Rankin scale at baseline, after 4 and 8 weeks of inclusion. Results: There was a significant difference in the mean change of Ashworth score from baseline to 4th week of the studied patients compared to the Control (p b 0.001), and from baseline to 8th week of the studies patients compared to the control group (p b 0.001) There was a significant difference in the mean change of the modified Rankin score from baseline to 4th week of the studied patients compared to the control (p b 0.001) and from baseline to 8th week of the studied patients compared to the control (p b 0.001) Conclusion: Both groups attained clinically significant improvement, however more apparent in the study group compared to the baseline, and to correlate this to the presence of HBOT, a further study of patients after attaining a state of Neurological stability is recommended.
Revista chilena de cirugía, 2013
Prognostic value of pathological response to chemo radiotherapy of locally advanced low rectal ca... more Prognostic value of pathological response to chemo radiotherapy of locally advanced low rectal cancer Background: Preoperative chemo radiotherapy improves the prognosis of locally advanced low rectal cancer and induces a pathological response in the tumor, which may have prognostic value. Aim: To assess the results of rectal cancer treatment according to the degree of pathological response of the tumor after chemo radiotherapy. Patients and Methods: All patients with a locally advanced rectal cancer located within 11 cm of the rectal margin, subjected to preoperative chemo radiotherapy followed by surgical treatment in a period of 13 years, were included. Pathological response was classified as complete, intermediate and poor. The tumor was staged according to TNM 2002 classification. Survival was analyzed with Kaplan Meier curves and Cox regression. Results: Patients were followed for a mean of 50 months (range 18-156). Exclusive and global local relapse was observed in 3 and 9.6% of patients, respectively. Pathological response was complete in 13 patients (none died), intermediate in 23 (three died) and poor in 68 (22 died). Global five years survival was 74%. There was a concordance of 0.64 between survival and pathological response. The concordance between survival and TNM classification was 0.69. Conclusions: The pathological response of the tumor to chemo radiotherapy has a good concordance with prognosis, although it is not superior to the final pathological status.
Background Several studies have shown that in Chile income inequality is relevant in explaining i... more Background Several studies have shown that in Chile income inequality is relevant in explaining inequities in health outcomes. The COVID-19 pandemic has also had a non-neutral impact, with higher mortality rates in municipalities with lower socioeconomic status. Methods We study inequity in mortality based on Potential Years of Life Lost (PYLL) in 34 urban municipalities of the Metropolitan Region (Greater Santiago) and analyze its evolution between 2018 and 2021 and by COVID-19 waves. In order to compare the results obtained for PYLL, we also computed the mortality rates adjusted by direct standardization. In addition, we used the concentration index to measure the health inequalities between municipalities. Results In the first year of the pandemic, the absolute PYLL and the crude mortality rate for all causes of death showed an increase of 13.6% and 19.8%, respectively. Moreover, 409,086 years of life were prematurely lost in 2020, one-fifth of them due to COVID-19. The concentra...
International Journal of Environmental Research and Public Health, 2021
The identification of COVID-19 waves is a matter of the utmost importance, both for research and ... more The identification of COVID-19 waves is a matter of the utmost importance, both for research and decision making. This study uses COVID-19 information from the 52 municipalities of the Metropolitan Region, Chile, and presents a quantitative method—based on weekly accumulated incidence rates—to define COVID-19 waves. We explore three different criteria to define the duration of a wave, and performed a sensitivity analysis using multivariate linear models to show their commonalities and differences. The results show that, compared to a benchmark definition (a 100-day wave), the estimations using longer periods of study are worse in terms of the model’s overall fit (adjusted R2). The article shows that defining a COVID-19 wave is not necessarily simple, and has consequences when performing data analysis. The results highlight the need to adopt well-defined and well-justified definitions for COVID-19 waves, since these methodological choices can have an impact in research and policy mak...
International Journal of Environmental Research and Public Health
The identification of COVID-19 waves is a matter of the utmost importance, both for research and ... more The identification of COVID-19 waves is a matter of the utmost importance, both for research and decision making. This study uses COVID-19 information from the 52 municipalities of the Metropolitan Region, Chile, and presents a quantitative method—based on weekly accumulated incidence rates—to define COVID-19 waves. We explore three different criteria to define the duration of a wave, and performed a sensitivity analysis using multivariate linear models to show their commonalities and differences. The results show that, compared to a benchmark definition (a 100-day wave), the estimations using longer periods of study are worse in terms of the model’s overall fit (adjusted R2). The article shows that defining a COVID-19 wave is not necessarily simple, and has consequences when performing data analysis. The results highlight the need to adopt well-defined and well-justified definitions for COVID-19 waves, since these methodological choices can have an impact in research and policy mak...
International Journal of Environmental Research and Public Health
The identification of COVID-19 waves is a matter of the utmost importance, both for research and ... more The identification of COVID-19 waves is a matter of the utmost importance, both for research and decision making. This study uses COVID-19 information from the 52 municipalities of the Metropolitan Region, Chile, and presents a quantitative method—based on weekly accumulated incidence rates—to define COVID-19 waves. We explore three different criteria to define the duration of a wave, and performed a sensitivity analysis using multivariate linear models to show their commonalities and differences. The results show that, compared to a benchmark definition (a 100-day wave), the estimations using longer periods of study are worse in terms of the model’s overall fit (adjusted R2). The article shows that defining a COVID-19 wave is not necessarily simple, and has consequences when performing data analysis. The results highlight the need to adopt well-defined and well-justified definitions for COVID-19 waves, since these methodological choices can have an impact in research and policy mak...
International Journal of Epidemiology
Pharmacoepidemiology and Drug Safety
Revista médica de Chile
Effectiveness and tolerability of low volume bowel cleansing polyethylene glycol solution for col... more Effectiveness and tolerability of low volume bowel cleansing polyethylene glycol solution for colonoscopy Background: A successful colonoscopy depends, among other factors, on a proper colon cleansing. This variable also affects the acceptance of the patient to carry out the study. Aim: To analyze the efficacy and tolerability of a low volume polyethylene glycol formulation (2 liters), compared to the conventional presentation of 4 liters. Material and Methods: Patients referred for a colonoscopy were randomly divided to receive either two or four liter of polyethylene glycol as bowel cleansing, which was assessed using the Boston score. Raters of the latter were blinded to the volume of polyethylene glycol that the patients used. Results: Seventy-four patients participated in the study. Subjects who received a 4 liters preparation had an average Boston score of 7.78, versus 8.16 for patients who received a volume of 2 liters (p = 0.267). No significant differences in tolerability were observed between both groups. No significant differences in the efficacy and tolerability between a conventional or a reduced volume of polyethylene glycol solution for the preparation of a colonoscopy were observed. These findings may be especially important for subgroups of patients with difficulties for oral administration of fluids. (Rev Med Chile 2019; 147: 977-982)
The American journal of tropical medicine and hygiene, Jan 25, 2018
From 1975 to 1983, a large epidemic of typhoid fever (TF) affected the metropolitan region (MR) o... more From 1975 to 1983, a large epidemic of typhoid fever (TF) affected the metropolitan region (MR) of Chile (incidence rate [IR] of 219.6 per 10 in 1983). In 1983-1984, interventions were implemented focusing on person-to-person transmission (vaccination, food handlers' control, and mass communication) and regulations to control irrigation waters containing fecal contaminates. In 1991, a second intervention was quickly implemented to avoid the cholera epidemic-affecting neighboring countries (total prohibition of growing or selling crops in the MR). We explored the potential impact of these interventions on the epidemic. We created a yearly database of the MR TF cases, population, and contextual factors of TF from 1969 to 2012. We first analyzed the epidemic (Joinpoint regression), identified predictors of TF (Poisson multiple regression), and then analyzed the effect of the interventions (interrupted time series model). The main predictor of the TF epidemic was the rate of unemplo...
Revista Medica De Chile, May 1, 2014
procedencia indígena como factores de riesgo de problemas nutricionales de los niños que ingresan... more procedencia indígena como factores de riesgo de problemas nutricionales de los niños que ingresan a la escuela. Salud Publica Mex 2009;51:187-193.
Revista Chilena de Pediatría, 2015
To analyse the outcomes of births and anthropometric measurements at birth of children born betwe... more To analyse the outcomes of births and anthropometric measurements at birth of children born between 1974 and 2011 at Limache Hospital (Valparaíso, Chile). Times series were constructed of births, weight and length at birth, and low weight and length at birth. The trend was modelled with linear and logistical regressions using splines to represent breaks in the trend by decade. The series includes 17,574 births. There was an increase in births per year in the 1970s (30/year) and declines in them to 17 and 22 births/year in the 1980s and 1990s, respectively (P<.001), with no significant trend thereafter. Newborns from 2000 to 2011 weighed 266 grams more than those in the 1970s (P<.001), and have now reached a mean weight of 3,530g. Low birthweight fell from 8% in the 1970s to 1.1% after 2000. Birth length increased by 1cm in the 37 years studied, with a reduction of low birth length from 7.6% to 2.1% during the period. Live births in the Limache Hospital declined, and anthropometric measurements at birth improved in the years analysed. This information is useful in developing interventions, taking into account the possible selection biases that could distort these estimates and their interpretation.
Revista médica de Chile, 2006
Temuco (304,000 inhabitants) has high levels of air pollution, mainly due to fine particulate mat... more Temuco (304,000 inhabitants) has high levels of air pollution, mainly due to fine particulate matter of less than 10 microm (PM10). The effects of this pollution on population health have not been studied. To study the short-term effects of PM10 on daily mortality in Temuco, in Southern Chile, due to respiratory and cardiovascular causes. We followed the APHEA methodology (Air Pollution and Health European Approach) by estimating poisson multivariate regression models and controlling by trends, seasonality and meteorology. The PM10 variable was introduced after controlling by the confounders and checking by statistical adjustment and autocorrelation of errors. Mortality data was obtained from the Ministry of Health, registering age, gender, place of residence and cause of death. Cancer, respiratory and cardiovascular deaths, occurring between 1997 and 2002, were recorded for this study. There was a significant and positive association between PM10 concentration and daily mortality c...