Screening Tool for Restrictive and Obstructive Ventilatory Abnormalities in a Population-Based Survey

BACKGROUND

A 6 s spirometry with an inexpensive pocket spirometer efficiently selects individuals for a diagnostic-quality spirometry for airflow limitation, but could also be useful to identify individuals with a restrictive pattern.

OBJECTIVES

We evaluated an inexpensive simplified spirometer (chronic obstructive pulmonary disease [COPD]-6) as a screening tool to identify spirometric abnormalities.

METHODS

A population-based survey in Mexico City, with 742 participants performing pre- and post-BD spirometry and a three-maneuver 6 s spirometry (pre-BD) with a COPD-6. We evaluated forced expiratory volume in 1 s (FEV1), FEV6, and FEV1/FEV6 from the COPD-6, crude and expressed as the percentage of predicted (%P), to discriminate post-bronchodilator airflow obstruction (FEV1/forced vital capacity [FVC] < 5th percentile) or restriction (FVC or FEV1 <5th percentile with normal FEV1/FVC) through receiver operating characteristics and their area under the curve (AUC).

RESULTS

FEV1%P was the best predictor to identify pre- and post-BD ventilatory abnormalities (best cutoff point 87%P, AUC 92% for restrictive pattern, 89% for obstructive pattern, and 91% for any spirometric abnormality). Deriving to clinical spirometry only those with < 87%P (26% of the sample) missed only 12% of spirometric abnormalities most of the latter mild.

CONCLUSIONS

An FEV1 < 87%P from a pre-BD 6 s spirometry correctly identified individuals with spirometric ventilatory defects, either obstructive or restrictive.

Dietary flavonoids improve urinary arsenic elimination among Mexican women

Inorganic arsenic (iAs) exposure increases risk of several diseases, including cancer. Some nutrients such as flavonoids enhance glutathione activity, which in turn play a key role in iAs elimination. Our objective was to explore whether dietary non-soy flavonoids are associated with iAs metabolism. We hypothesized that the intake of flavonoids belonging to the following groups, flavan-3-ols, flavone, flavonol, flavanone, and anthocyanidin, is positively associated with urinary dimethylarsinic acid (DMA), which is the most soluble iAs metabolite excreted. We performed a cross-sectional study that included 1027 women living in an arsenic-contaminated area of northern Mexico. Flavonoid intake was estimated using a validated food frequency questionnaire. Concentration of urinary iAs and its metabolites (monomethylarsonic acid and DMA) were determined by high performance liquid chromatography ICP-MS. Results showed positive significant associations between DMA and the flavonoid groups flava-3-ols (β= 0.0112) and flavones (β= 0.0144), as well as the individual intake of apigenin (β= 0.0115), luteolin (β= 0.0138), and eriodictyol (β= 0.0026). Our findings suggest that certain non-soy flavonoids may improve iAs elimination; however, there is still very limited information available regarding the consumption of flavonoids and iAs metabolism.

Arsenic metabolism and cancer risk: A meta-analysis

OBJECTIVE

To describe the studies that have reported association measures between risk of cancer and the percentage distribution of urinary inorganic arsenic (iAs) metabolites by anatomical site, in non-ecological epidemiological studies.

METHODS

Studies were identified in the PubMed database in the period from 1990 to 2015. Inclusion criteria were: non-ecological epidemiological study, with histologically confirmed cancer cases, reporting the percentage distribution of inorganic arsenic (iAs), monomethylated (MMA) and dimethylated (DMA) metabolites, as well as association measures with confidence intervals (CI) between cancer and %iAs and/or %MMA and/or %DMA. A descriptive meta-analysis was performed by the method of the inverse of the variance for the fixed effects model and the DerSimonian and Laird's method for the random effects model. Heterogeneity was tested using the Q statistic and stratifying for epidemiological design and total As in urine. The possibility of publication bias was assessed through Begg's test.

RESULTS

A total of 13 eligible studies were found, most of them were performed in Taiwan and focused on skin and bladder cancer. The positive association between %MMA and various types of cancer was consistent, in contrast to the negative relationship between %DMA and cancer that was inconsistent. The summary risk of bladder (OR=1.79; 95% CI: 1.42, 2.26, n=4 studies) and lung (OR=2.44; 95% CI: 1.57, 3.80, n=2 studies) cancer increased significantly with increasing %MMA, without statistical heterogeneity. In contrast, lung cancer risk was inversely related to %DMA (OR=0.58; 95% CI: 0.36, 0.93, n=2 studies), also without significant heterogeneity. These results were similar after stratifying by epidemiological design and total As in urine. No evidence of publication bias was found.

CONCLUSION

These findings provide additional support that methylation needs to be taken into account when assessing the potential iAs carcinogenicity risk.

Phthalate exposure, flavonoid consumption and breast cancer risk among Mexican women

OBJECTIVE

To evaluate if selected phthalate exposure and flavonoid intake interact on breast cancer (BC) risk.

MATERIAL AND METHODS

Interviews and urine samples were obtained from 233 women with histologically confirmed BC and 221 healthy controls matched by age and place of residence, from various states of northern Mexico. Urinary metabolites concentrations of diethyl phthalate (DEP), butyl benzyl phthalate (BBzP) and dioctyl phthalate (DOP) were determined by solid-phase extraction coupled with high-performance liquid chromatography/isotope dilution/tandem mass spectrometry. Using a semiquantitative food frequency questionnaire, consumption of five types of flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones and flavonols) was estimated according to three food groups: vegetables, fruits and legumes-oil seeds.

RESULTS

A higher intake of anthocyanidins and flavan-3-ols (from vegetables), synergistically increased the negative association between BBzP and BC. No other significant flavonoid-phthalate multiplicative interactions on the risk for BC were found.

CONCLUSION

The consumption of some flavonoids may interact with exposure to phthalates on the risk of BC. Epidemiological and underlying mechanisms information is still insufficient and requires further investigations.

Dietary micronutrient intake and its relationship with arsenic metabolism in Mexican women

INTRODUCTION

Concentrations of inorganic arsenic (iAs) metabolites in urine present intra- and interindividual variations, which are determined not only by the magnitude of exposure to iAs, but also by differences in genetic, environmental and dietary factors.

OBJECTIVE

To evaluate whether differences in dietary intake of selected micronutrients are associated with the metabolism of iAs.

METHODS

The intake of 21 micronutrients was estimated for 1027 women living in northern Mexico using a food frequency questionnaire. Concentration of urinary metabolites of iAs was determined by high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and the proportion of iAs metabolites was calculated (%iAs, monomethylarsonic acid [%MMA] and dimethylarsinic acid [%DMA]), as well as ratios corresponding to the first (MMA/iAs), second (DMA/MMA) and total methylation (DMA/iAs).

RESULTS

After adjustment for covariates, it was found that methionine, choline, folate, vitamin B12, Zn, Se and vitamin C favor elimination of iAs mainly by decreasing the %MMA and/or increasing %DMA in urine.

CONCLUSIONS

Our results confirm that diet contributes to the efficiency of iAs elimination. Further studies are needed to assess the feasibility of dietary interventions that modulate the metabolism of iAs and the consequent risk of diseases related to its exposure.

Breast cancer age at diagnosis patterns in four Latin American Populations: A comparison with North American countries

BACKGROUND

In the Latin America countries (LAC), one in five breast cancer (BC) cases occur in women younger than 45 years, almost twice the frequency seen in developed countries. Most BC cases in younger women are premenopausal and are generally more difficult to detect at early stages and to treat than postmenopausal cancers. We employ data from four high quality population-based registries located in LAC and assess the extent to which the higher frequency of BC occurring in younger women is due to a younger population structure, compared to that of developed countries. Next, we analyze secular and generational trends of incidence rates in search for additional explanations.

METHODS

Using data from the International Agency for Research on cancer, between 1988 and 2007, the age distribution of BC incident cases for registries located in Brazil, Colombia, Costa Rica, Ecuador is compared to that of USA and Canadian registries, both before and after removing differences in population age structure. An age-period-cohort modelling of incidence rates is also conducted in all compared registries to identify secular and generational effects.

RESULTS

BC incident cases in the LAC registries present, on average, at an earlier age than in the USA and Canadian registries and for 2003-2007, between 20 and 27% of cases occur in women aged 20-44. About two thirds of the difference in age distribution between LAC and USA registries is attributable to the younger age distribution in the LAC base populations. The USA registries show the highest age-specific BC incidence rates of all compared aggregated registries, at all ages. However, in all the LAC registries incidence rates are rapidly increasing, fueled by a strong birth cohort effect. This cohort effect may be explained by important reduction in fertility rates occurring during the second half of the 20th century, but also by a greater exposure to other risk factors for BC related to the adoption of life styles more prevalent in developed countries.

CONCLUSION

The younger age at presentation of BC incident cases seen in the analyzed LAC registries, and possibly in many Latin American countries, is not only attributable to their relatively young population age structure but also to the low incidence rates in older women. As more recently born cohorts, with greater exposure to risk factors for postmenopausal BC, reach older age, incidence rates will be more similar to the rates seen in the USA and Canadian registries. There is a need for additional research to identify determinants of the higher BC rate among younger women in these countries.

[Prevalence of severe periodontal disease and its association with respiratory disease in hospitalized adult patients in a tertiary care center]

BACKGROUND

Severe periodontal disease is a chronic inflammatory gingival process associated with systemic diseases.

OBJECTIVE

To determine the prevalence of severe periodontal disease and its association with respiratory diseases among hospitalized patients at the Institute of Respiratory Diseases "Ismael Cosio Villegas" (INER) in 2011.

MATERIAL AND METHODS

A cross-sectional study was developed. The severe periodontal disease was diagnosed by the Department of Stomatology. The International Classification of Diseases 10th revision was used. A multinomial logistic was fit to estimate relative-risk.

RESULTS

Three thousand and fifty-nine patients were included; 772/3,059 (25.2%) had severe periodontal disease. After controlling for age, sex, inpatient days, death, and socioeconomic status, the infectious respiratory diseases that were significantly associated with severe periodontal disease were: HIV/AIDS (RR: 10.6; 95% CI: 9.1-23.3; p < 0.0001); pneumonia (RR: 2.6; 95% CI: 2.2-5.7; p < 0.0001); pulmonary tuberculosis and its sequels (RR: 2.1; 95% CI: 1.6-4.9; p < 0.0001); and lung abscess (RR: 2.6; 95% CI: 1.6-7.8; p = 0.002). Lung cancer and pleural diseases were also significantly associated with severe periodontal disease.

CONCLUSIONS

High prevalence of severe periodontal disease was observed in the different respiratory diseases. Severe periodontal disease was associated with both infectious and non-infectious respiratory diseases. It is important to study an oral health intervention.

Corrección de la mala clasificación de las muertes por sida en México.Análisis retrospectivo de 1983 a 2012

Objetivo. Identificar y reasignar defunciones mal clasificadas por sida en México, y reconstruir la mortalidad 1983-2012, por entidad federativa, sexo, edad y derechohabiencia a la seguridad social. Material y métodos. Se analizaron 15.5 millones de defunciones de 1979 a 2012. La corrección de la mortalidad por sida se hizo en tres fases: a) por causas directamente relacionadas con sida, y b) por muertes mal codificadas; c) muertes por sida ocultas en otras causas. Se calcularon tasas estandarizadas por edad de mortalidad (TEM) por sexo, derechohabiencia a la seguridad social y entidad federativa. Resultados. Se acumularon 107 981 muertes por sida entre 1983 y 2012 (11% más del total de muertes observadas). La TEM en hombres, para todos los grupos de edad, empieza a descender desde 1996, mientras que para las mujeres la caída inicia en 2008. Un panorama similar se observa para la población con/sin seguridad social. La heterogeneidad caracteriza la TEM estatal. Conclusión. Se presenta una metodología fácilmente replicable para la corrección de la mortalidad de sida que genera información relevante para la toma de decisiones fundamentada en la evidencia.

[Correcting for misclassified HIV/aids deaths in Mexico: Retrospective analysis, 1983-2012]

OBJECTIVE

To identify and reassign misclassified AIDS deaths in Mexico, reconstructing the time series of mortality from 1983 to 2012, by state, sex, age, and affiliation to social security.

MATERIALS AND METHODS

15.5 million deaths from 1979 to 2012 were analyzed. The HIV-AIDS mortality correction was done in three phases: a) those causes directly related to AIDS; b) by miscoded deaths, and c) AIDS deaths hidden in other underlying causes of death. Age-standardized rates of mortality (SMR) were calculated by sex, affiliation to social security, and state.

RESULTS

107 981 AIDS deaths from 1983 to 2012 were accumulated, representing 11% of total deaths observed for the period. The SMR in men for all age groups begins to decline since 1996, while for women the decline started in 2008. A similar picture is observed for the population with / without social security. Heterogeneity is a feature for SMR by state.

CONCLUSION

An easily replicable methodology for the correction of mortality from AIDS, which generates relevant information for decision making based on the evidence is presented.

Health-related quality of life after surgery for hip fracture: a multicentric study in Mexican population

INTRODUCTION

Hip fractures are an important cause of morbidity and mortality and one of the main causes of disability in the older population. The lifetime risk for any type of osteoporotic fracture is very high and falls within the range of 40–-50% in women and 13–-22% for men. In Mexico, the lifetime likelihood of having a hip fracture at 50 years of age is 8.5% in Mexican women and 3.8% in Mexican men, but this is expected to rise in upcoming years.

AIM

This study aims to report the Health-Related Quality of Life over the first six months after a hip fracture in two public and two private tertiary care hospitals in Mexico City.

METHOD

Changes over time were evaluated through visual observation of each patient’s development trajectory using the graphic representation of the EQ-5D global score. The trajectories were grouped by affinity into five levels of progress according to clinical course. The identified descriptive options were analyzed using the multinomial logistic regression model (LR).

RESULTS

One-hundred-and-thirty-six (136) patients with a hip fracture were followed after surgery. Their mean age was 77 ± 10 years. During the first month, mobility, daily activities, and self-care were the most affected. The group aged between 80 and 84 years reported extreme problems regarding anxiety and depression (21%), and those aged between 50 and 74 years described having issues concerning pain and discomfort (27%). At the 6-month follow-up, only those aged > 85 years of age showed worsening of their condition, a high proportion of these ranking at level 3 in mobility, self-care, and anxiety/depression. Toward the end of the follow-up period, this last group reported having extreme problems (being unable to carry out everyday activities) and worsening of their mobility (9.2%) (inability to walk about) (LR test, p = 0.06).

DISCUSSION

Patients with hip fracture showed difficulties in different areas during the first month after surgery, with steady recuperation up to month six. Age was an important factor in the recovery of all evaluated domains. This graphical tool facilitates classification, identification, and monitoring Health-Related Quality of Life in patients with hip fractures.

[Burden of disease, injuries, risk factors and challenges for the health system in Mexico]

OBJECTIVE

To present the results of the burden of disease, injuries and risk factors in Mexico from 1990 to 2010 for the principal illnesses, injuries and risk factors by sex.

MATERIALS AND METHODS

A secondary analysis of the study results published by the Global Burden of Disease 2010 for Mexico performed by IHME.

RESULTS

In 2010, Mexico lost 26.2 million of Disability adjusted live years (DALYs), 56 % were in male and 44 % in women. The main causes of DALYs in men are violence, ischemic heart disease and road traffic injuries. In the case of women the leading causes are diabetes, chronic kidney disease and ischemic heart diseases. The mental disorders and musculoskeletal conditions concentrate 18% of health lost. The risk factors that most affect men in Mexico are: alcohol consumption, overweight/obesity, high blood glucose levels and blood pressure and tobacco consumption (35.6 % of DALYs lost). In women, overweight and obesity, high blood sugar and blood pressure, lack of physical activity and consumption of alcohol are responsible for 40 % of DALYs lost. In both sexes the problems with diet contribute 12% of the burden.

CONCLUSIONS

The epidemiological situation in Mexico, demands an urgent adaptation and modernization of the health system.

Late-life depressive symptoms: prediction models of change

BACKGROUND

Depression is a well-recognised problem in the elderly. The aim of this study was to determine the factors associated with predictors of change in depressive symptoms, both in subjects with and without baseline significant depressive symptoms.

METHODS

Longitudinal study of community-dwelling elderly people (>60 years or older), baseline evaluations, and two additional evaluations were reported. Depressive symptoms were measured using a 30-item geriatric depression scale, and a score of 11 was used as cut-off point for significant depressive symptoms in order to stratify the analyses in two groups: with significant depressive symptoms and without significant depressive symptoms. Sociodemographic data, social support, anxiety, cognition, positive affect, control locus, activities of daily living, recent traumatic life events, physical activity, comorbidities, and quality of life were evaluated. Multi-level generalised estimating equation model was used to assess the impact on the trajectory of depressive symptoms.

RESULTS

A number of 7882 subjects were assessed, with 29.42% attrition. At baseline assessment, mean age was 70.96 years, 61.15% were women. Trajectories of depressive symptoms had a decreasing trend. Stronger associations in those with significant depressive symptoms, were social support (OR.971, p<.001), chronic pain (OR 2.277, p<.001) and higher locus of control (OR.581, p<.001). In contrast for those without baseline significant depressive symptoms anxiety and a higher locus of control were the strongest associations.

CONCLUSIONS

New insights into late-life depression are provided, with special emphasis in differentiated factors influencing the trajectory when stratifying regarding basal status of significant depressive symptoms.

LIMITATIONS

The study has not included clinical evaluations and nutritional assessments.

La carga de enfermedad, lesiones, factores de riesgo y desafíos para el sistema de salud en México

Objetivo. Presentar los resultados de la carga de enfermedad en México de 1990 a 2010 para las principales enfermedades, lesiones y factores de riesgo, por sexo. Materiales y métodos. Se realizó un análisis secundario del estudio de la carga mundial de la enfermedad 2010. Resultados. En 2010 se perdieron 26.2 millones de años de vida saludable (AVISA), 56% en hombres y 44% en mujeres. Las principales causas de AVISA en hombres fueron violencia, cardiopatía isquémica y los accidentes de tránsito. En las mujeres fueron la diabetes, la enfermedad renal crónica y la cardiopatía isquémica. Los trastornos mentales y musculoesqueléticos concentran 18% de la carga. Los factores de riesgo que más afectan a los hombres son sobrepeso/obesidad; niveles de glucosa en sangre y de presión arterial elevados; y el consumo de alcohol y tabaco (35.6% de AVISA perdidos). En las mujeres, el sobrepeso y la obesidad; glucosa elevada; hipertensión arterial; baja actividad física; y el consumo de alcohol y tabaco fueron responsables de 40% de los AVISA perdidos; en ambos sexos, la dieta contribuye con 12% de la carga. Conclusiones. El panorama epidemiológico en México demanda una urgente adecuación y modernización del sistema de salud.

[National consensus of diagnosis and treatment of non-small cell lung cancer]

Mexican specialists in oncology, oncologic surgery, thoracic surgery, pneumology, pathology, molecular biology, anesthesiology, algology, psychology, nutrition, and rehabilitation (all of them experts in lung cancer treatment) in order to develop the National Consensus on Lung Cancer. The consensus has been developed as an answer to the need of updated Mexican guidelines for the optimal treatment of the disease, as well as to the requirements that such guidelines be established by multidisciplinary panel, depicting the current attention given to cancer lung cases in Mexico. Thus, this paper analyses the epidemiological review, screening, diagnosis, staging, pathology, translational medicine, and the suitable therapies for early, locally advanced, and metastatic disease in the first, second, and third lines of management, as well as rehabilitation and palliative measures.

Nurse home visits with or without alert buttons versus usual care in the frail elderly: a randomized controlled trial

OBJECTIVE

To assess whether an intervention based on nurse home visits including alert buttons (NV+AB) is effective in reducing frailty compared to nurse home visits alone (NV-only) and usual care (control group) for older adults.

DESIGN

Unblinded, randomized, controlled trial.

SETTING

Insured population covered by the Mexican Social Security Institute living in the city of Ensenada, Baja California, Mexico.

PARTICIPANTS

Patients were aged over 60 years with a frailty index score higher than 0.14.

INTERVENTION

After screening and informed consent, participants were allocated randomly to the control, NV+AB, or NV-only groups.

MEASUREMENTS

The primary outcome was the frailty score 9 months later. Quality of life, depression, comorbidities, health status, and health service utilization were also considered.

RESULTS

The framing sample included 819 patients. Of those, 591 were not located because they did not have a landline/telephone (341 patients), they had died (107), they were ill (50), or they were not currently living in the city (28). A screening interview was applied to 228 participants, and 57 had a score ≤0.14, 171 had ≥0.14, and 16 refused to complete the baseline questionnaire. A home visit was scheduled for 155 patients. However, 22 did not complete the baseline questionnaire. The final 133 subjects were randomized into the NV+AB (n = 45), NV-only (n = 44), and control (n = 44) groups. There were no statistically significant differences in the baseline characteristics of the groups. The mean age overall was 76.3 years (standard deviation 4.7) and 45% were men. At the baseline, 61.65% were classified as frail. At end of follow-up the adjusted prevalence of frailty in NV+AB group was 23.3% versus 58.3% in the control group.

CONCLUSION

An intervention based on NV+AB seems to have a positive effect on frailty scores.

[Adult asthma in Mexico City: a population-based study]

OBJECTIVES

To determine the prevalence of asthma and the association between sociodemographic characteristics, spirometry, respiratory symptoms, quality of life and sleep in adults > 40 years.

MATERIALS AND METHODS

This report is part of our study (Latin American Research Project Obstructive Pulmonary), held in Mexico City and the metropolitan area in 2003. We used logistic regression models adjusted for study design, where asthma was the dependent and independent variable respiratory symptoms, sociodemographic and clinical characteristics among others.

RESULTS

The prevalence of physician-diagnosed asthma was: 3.3% in men and 6.2% in women. Decreased lung function in asthmatics was observed. In multivariate analysis, after adjusting for potential confounders, asthmatics had a higher risk of excessive daytime sleepiness more snoring [OR = 3.2 (95% CI 1.4-7.4), p= 0.008], and more frequent work absences due to respiratory problems [OR = 5.1 (95% CI 2.5-10.4), p<0.0001].

CONCLUSIONS

The prevalence of asthma was 5%. Asthmatics showed lower quality of life and lung function.

Demand for care and nosocomial infection rate during the first influenza AH1N1 2009 virus outbreak at a referral hospital in Mexico City

OBJECTIVE

Comparison of routine hospital indicators (consults at the Emergency Room (ER) and hospital admissions) during the 2009 pandemic of the influenza AH1N1 virus at the national referral hospital for respiratory diseases in Mexico City.

MATERIAL AND METHODS

The outbreak was from April to mid-May 2009 and two control periods were used:2009 (before and after the outbreak),and during April-May from 2007 and 2008.

RESULTS

During the outbreak total consultation at the ER increased six times compared with the 2007-2008 control period and 11 times compared with the 2009 control period. Pneumonia- or influenza-related ER consultations increased 23.2 and 15.3%, respectively. The rate of nosocomial infection during the outbreak was 13.6 and that of nosocomial pneumonia was 6 per/100 hospital discharges, a two-fold and three-fold increase compared to the control periods respectively.

CONCLUSIONS

During the outbreak,mean severity of admitted patients increased,with a rise in in-hospital mortality and nosocomial infections rate, including nosocomial pneumonia.

Comparison of a geriatric unit with a general ward in Mexican elders

There is evidence that geriatric services may be more effective in handling problems of the elderly in acute care. We therefore studied a cohort of matched triplets (age, gender and admission diagnosis), to assess the effect of a geriatric service on elderly problems (falls, pressure ulcers, delirium and functional decline). This is a follow up study; comparing a geriatric unit with an internal medicine unit at two hospitals of the Mexican Institute of Social Security (IMSS) in Mexico City. Socio-demographic characteristics, functionality, emotional state, cognitive status, delirium, co-morbidities, diagnosis, number of medications, presence of pressure ulcers and falls, were assessed. We developed a composite variable as a global end-point, including: delirium, falls, mortality, pressure sores and functional decline. 70 patients were included in the geriatric services and 140 in the internal medicine unit. Mean age =72.5±7 years (±S.D.), and 52.9% were women. At baseline, only illiteracy, quality of life and the number of medications were statistically different between each group. Fully adjusted multiple logistic conditional regression model found an odds ratio of 0.27 (95% CI 0.1-0.7) for the presence of the composite variable, favoring the geriatric unit. Geriatric units in acute care may be beneficial in different frequent end points in elderly.

[Burden of disease in Latin America]

OBJECTIVE

To describe the burden of disease studies made in the region, identify the main priorities in health from the indicator Disability Adjusted Life Years (DALYs).

MATERIAL AND METHODS

By the use of DALYs identify the burden of disease in the countries in the network.

RESULTS

DALYs emphasize the emergency of mental disorders, diabetes mellitus in women and the disorders associated with alcohol consumption and injuries in men.

CONCLUSIONS

Latin America is the region with more national studies of burden of disease, using a standardized methodology, that allows identifying new health priorities which are pressing to the health services; for that reason these results constitute an element to take into account in the establishment of public policies in each country.

[Progress on the Millenium Development Goals 4 and 5 in Mesoamerica]

OBJECTIVES

To describe the advances made by countries in the Mesoamerican region towards reaching Millenium Development Goals (MDG) 4 and 5, and discuss the most useful tasks to help the region in accomplishing or keeping track of these objectives.

MATERIAL AND METHODS

The trend estimates of maternal and under 5 mortality from 1990 to 2008, the effective coverage of vaccination against diphteria, pertussis and tetanus (DPT), prenatal care and childbirth by qualified personnel were taken from the Institute of Health Metrics and Evaluation (IHME) and the causes of death for children under five were taken from the Children's Health Epidemiology Reference Group of WHO (CHERG).

RESULTS

The regional trend in the rate of mortality for children under five (MDG-4) in the last 18 years shows an annual reduction of 4.2%, significantly above the global reduction of 2.1%. This suggests that countries of Mesoamerica will be able to fulfill this objective. In contrast, data for 2008 shows that the rate of reduction of maternal mortality is very heterogeneous and it is unlikely that any of the countries in the region will reach this goal.

CONCLUSION

Efforts made by countries in Mesoamerica have been substantial in controlling mortality in children under five years but insufficient to achieve MDG-5. Although the tendency is in the right track the reduction rate will only partially fulfill the acquired commitments to eradicate poverty.

Pandemic (H1N1) 2009 virus and Down syndrome patients

We compared prevalence of hospitalization, endotracheal intubation, and death among case-patients with and without Down syndrome during pandemic (H1N1) 2009 in Mexico. Likelihoods of hospitalization, intubation, and death were 16-fold, 8-fold, and 335-fold greater, respectively, for patients with Down syndrome. Vaccination and early antiviral drug treatment are recommended during such epidemics.

Breast cancer mortality in Mexico: an age-period-cohort analysis

OBJECTIVE

To assess the age, period and cohort effects on breast cancer (BC) mortality in Mexico.

MATERIAL AND METHODS

Age, period and cohort curvature trends for BC mortality were estimated through the Poisson Regression model proposed by Holford.

RESULTS

Nationally, BC death rates have leveled off since 1995 in most age groups. BC mortality trends are mainly determined by birth cohort and age effects in Mexico. Women born between 1940 and 1955 show the highest rate of increase in BC mortality. Women born afterwards still show an increasing trend but at a much lower rate. Mammography and adjuvant therapy have had a limited impact on mortality. Potential reasons for observed patterns are discussed. An increase in BC mortality in Mexico is expected in the following decades.

CONCLUSIONS

Mammography screening programs and timely access to effective treatment should be a national priority to reverse the expected increasing BC mortality trend.

[Adult smoking trends in Mexico between 1988 and 2008]

OBJECTIVE

To describe the changes in several smoking indicators occurred in Mexico over the past two decades and to explore if the tobacco control policies implemented in Mexico, since 2004, show a favorable impact on tobacco consumption by 2008.

MATERIALS AND METHODS

We analyze trends in comparable data on the prevalence of never and daily smokers, using the five National Addiction Surveys conducted between 1988 and 2008. The analysis is restricted to persons aged 18 through 65 years. Data are adjusted for age, sex and marginality index.

RESULTS

Between 2002 and 2008 the percentage of never smokers has increased by 19.6% and the percentage of daily smokers has decreased by 24.8%. These changes were more important in men, but in women the average number of cigarettes consumed decreased by 21.1% over the compared period and there was also a 13.9% rise in the percentage of women attempting to quit. Daily smokers prevalence has declined more rapidly since 2005, coincidently with an increase in cigarette taxation.

CONCLUSIONS

Over the past two decades there has been in Mexico an increase in the percentage of never smokers and a decline in the percentage of daily smokers. A positive impact is observed, few years after the implementation of more effective tobacco control policies in Mexico, notably higher taxation of tobacco products.

A frailty index to predict the mortality risk in a population of senior Mexican adults

BACKGROUND

Frailty in the elderly can be regarded as nonspecific vulnerability to adverse health outcomes, caused by multiple factors. The aim was to analyze the relationships between the frailty index, age and mortality in a two year follow up study of Mexican elderly.

METHODS

A frailty index was developed using 34 variables. To obtain the index, the mean of the total score for each individual was obtained. Survival analyses techniques were used to examine the risk ratios for the different levels of the frailty index. Kaplan-Meier estimates were obtained, adjusted for age and gender. Cox proportional hazards models were also built to obtain hazard ratio estimates.

RESULTS

A total of 4082 participants was analyzed. Participants had an average age of 73 years and 52.5% were women. On average, participants were followed-up for 710 days (standard deviation = 111 days) and 279 of them died. Mortality increased with the frailty index level, especially in those with levels between .21 to .65, reaching approximately 17% and 21%, respectively. Cox proportional hazards models showed that participants with frailty index levels associated to increased mortality (.21 and higher) represent 24.0% of those aged 65-69 years and 47.6% of those 85 and older.

CONCLUSION

The frailty index shows the properties found in the other studies, it allows stratifying older Mexican into several groups different by the degree of the risk of mortality, and therefore the frailty index can be used in assessing health of elderly.

Depressive symptoms among older adults in Mexico City

BACKGROUND

Ageing and depression are associated with disability and have significant consequences for health systems in many other developing countries. Depression prevalence figures among the elderly are scarce in developing countries.

OBJECTIVE

To estimate the prevalence of depressive symptoms and their cross-sectional association with selected covariates in a community sample of Mexico City older adults affiliated to the main healthcare provider.

DESIGN

Cross-sectional, multistage community survey.

PARTICIPANTS

A total of 7,449 persons aged 60 years and older.

MEASUREMENTS

Depression was assessed using the 30-item Geriatric Depression Scale (GDS); cognitive impairment, using the Mini-Mental State Examination; and health-related quality of life with the SF-36 questionnaire.

MAIN RESULTS

The prevalence of significant depressive symptoms was estimated to be 21.7%, and 25.3% in those aged 80 and older. After correcting for GDS sensitivity and specificity, major depression prevalence was estimated at 13.2%. Comparisons that follow are adjusted for age, sex, education and stressful life events. The prevalence of cognitive impairment was estimated to be 18.9% in depressed elderly and 13.7% in non-depressed. SF-36 overall scores were 48.0 in depressed participants and 68.2 in non-depressed (adjusted mean difference = -20.2, 95% CI = -21.3, -19.1). Compared to non-depressed elderly, the odds of healthcare utilization were higher among those depressed, both for any health problem (aOR 1.4, 95% CI = 1.1, 1.7) and for emotional problems (aOR 2.7, 95% CI = 2.2, 3.2).

CONCLUSIONS

According to GDS estimates, one of every eight Mexican older adults had major depressive symptoms. Detection and management of older patients with depression should be a high priority in developing countries.

Role of active and passive smoking on lung cancer etiology in Mexico City

OBJECTIVE

[corrected] To estimate the association between passive and active smoking exposures and lung cancer in Mexico City and the corresponding attributable risks.

MATERIAL AND METHODS

Data was analyzed from a multicenter population-based case-control study conducted in Mexico City.

RESULTS

ORs for lung cancer in ever smokers were 6.2 (95% CI 3.9-10.2) for males and 2.8 (95% CI 1.7-4.4) for females. Passive smoking at home showed an overall OR of 1.8 (95% CI 1.3-2.6), similar in both genders. Attributable risk for active smoking for both genders combined, and for males and females separately, was estimated at 55, 76 and 27%, respectively. Attributable risk for passive smoking at home was 17% for females, 3.9% for males and 12% for the entire population.

CONCLUSIONS

In Mexico City smoking is attributable to a smaller proportion of lung cancer cases than in developed countries. This is explained by a lower intensity of smoking in the Mexican population.

[Risk factors in invasive cervical cancer among Mexican women]

OBJECTIVE

To evaluate the association between invasive Cervical Cancer (CC) and high risk Human PapillomaVirus (HR-HPV) (viral load and type 16), along with other gynecological and socioeconomic factors.

MATERIAL AND METHODS

Individually matched case-control study (215 women with invasive CC and 420 controls). The study population was recruited between 2000 and 2001. A set of variables traditionally linked with CC (gynecological and socioeconomic factors) and two variables related to HPV infection (viral load and type 16) were assessed. Hybrid Capture II was used to detect HR-HPV DNA. Viral load was measured by light measurements expressed as relative light units (RLU) and they were categorized for analysis into four groups: negative (< 1 RLU), low viral load (1-49 RLU), middle load (50-499 RLU) and high load (>499 RLU). The analysis included univariate, bivariate and multivariate techniques being the final step the estimation of Odds Ratios (OR) by means of conditional logistic regression models. Results. The probability of having invasive CC was 78 times higher in patients with infection of HR-HPV. Risk increases with HPV type 16 (OR = 429.7) as compared with other types of HR-HPV (OR = 64.1). An important trend was observed with the increase of the viral load (from 46.6 with low viral load; to 250.7 with intermediate and 612.9 with high load). The findings also indicate significant diferences in the viral load between cases and controls according to age groups and HR-HPV types (16 versus others high risk types). Finally, the partner-demographic and obstetrical variables related to the disease increased the risk of invasive CC. No association between CC and smoking was observed in this population.

CONCLUSIONS

This study helps in identifying women at higher risk of developing invasive CC as a subset of those patients infected with HR-HPV. The findings point strongly to the importance of the viral load in HR-HPV as a co-factor in the development of this disease. This biomarker contributes to improving the prevention and early detection of this disease and also to identify women at higher risk who carry a high viral load of HR-HPV.

Incidence rates and life-time risk of hip fractures in Mexicans over 50 years of age: a population-based study

The vast majority of hip fractures in the 21st century will occur in the developing countries. The rates and life-time hip fracture risk are not known for Mexico, and for this reason, we studied the incidence of hip fractures, and the remaining life-time probability of having a hip fracture at the age of 50 years in Mexican men and women. All hip fracture cases registered during the year 2000 were collected at all the main tertiary-care hospitals in the two major health systems in México City, Instituto Mexicano del Seguro Social (IMSS) and Ministry of Health (SS), and the diagnosis was validated by chart review in all cases. The annual rates of hip fracture were 169 in women and 98 in men per 100,000 person-years. The life-time probability of having a hip fracture at 50 years of age was 8.5% in Mexican women and 3.8% in Mexican men. We conclude that hip fractures are an important health problem in Mexico and that Mexican health authorities should consider public health programs to prevent hip fractures.

[Breast feeding and the incidence of acute diarrhea during the first three months of life]

OBJECTIVE

To assess the effect of exclusive breastfeeding and its interactions with selected socioeconomic factors, on the incidence of acute infantile diarrhea during the first three months of life.

MATERIAL AND METHODS

A prospective cohort study with a follow up of three months was conducted in 327 mother and child pairs, living in the city of Durango, Mexico, between April and June 1994. Data analyses included simple univariate and bivariate cross-tabulations, as well as multivariate logistic regression models with random effects.

RESULTS

Infants who were not exclusively breastfed were at a significantly increased risk of having acute diarrhea during early infancy (ORcombined breastfeeding=3.23; 95% CI 1.84-5.68 and ORartificial breastfeeding=4.36; 95% CI 2.32-8.19). Moreover, the protective effect of breastfeeding was independent from the effects of the following factors: poor maternal education, lack of social support for baby care, and being an adolescent mother. However, lack of potable water and lack of sewerage were potential effect modifiers of type of lactation deltaG=9.26; p=0.09; ORno water/no sewerage= 2.58; 95% CI 1.10-6.03 in the final multivariate model), for simultaneous lack of potable water and sewerage, which is greater than the sum of the individual OR for each variable.

CONCLUSIONS

Similar to previous studies, exclusive breastfeeding was found to have great importance, since this practice protects the child's health and allows for a better development, despite unfavorable social and economic conditions. In particular, it seems that the protection conferred by breastfeeding is stronger when home conditions are poor, but this same condition presents an intervention opportunity, particularly the assurance of potable water provision for the infant when breastfeeding is not an option.

The impact of altitude on mortality from tuberculosis and pneumonia

OBJECTIVE

To examine the association between altitude and mortality from tuberculosis (TB) and pneumonia-influenza in Mexico.

DESIGN

We analysed specific causes of death in Mexico according to death certificates for the period 1993-1997, totalling over 2,700,000 deaths and including nearly 23,000 attributed to TB and 115,000 to pneumonia and influenza. Thirty population subgroups were formed based on altitude of residence (six categories) and level of poverty (five categories). The effect of altitude on mortality was estimated through Poisson regression models, with adjustment for age, gender and socioeconomic status.

RESULTS

Adjusted death rates for TB decreased with altitude and increased for pneumonia-influenza. Compared to people living below 500 m above sea level, those living between 2000 and 2499 m had a 58% mortality rate for TB and a three-fold increase in mortality due to pneumonia-influenza, despite adjustment for poverty, age and gender.

CONCLUSION

The mortality rate for TB based on death certificates decreases with altitude of residence, whereas the opposite is observed for pneumonia and influenza.

Effect of BCG vaccination in asthmatic schoolchildren

Recent studies have explored the effect of Bacilli Calmette-Guerin (BCG) or Mycobacterium vaccae vaccination in asthmatic patients, yielding conflicting results. We investigated the effect of BCG vaccination in asthmatic schoolchildren, especially focusing on the cytokine pattern released by mononuclear cells. After a 1-yr run-in period, 67 asthmatic schoolchildren received intradermal immunization with BCG (33 patients) or placebo (34 patients). Both groups were followed during 1 yr. Serum immunoglobulin E (IgE) levels did not change after BCG (407.1 +/- 86.6 vs. 415.1 +/- 86.7 IU/ml, mean +/- s.e.m.), but increased after placebo (406.7 +/- 67.0 vs. 619.7 +/- 90.7 IU/ml, p = 0.001) administration. Interleukin (IL)-4 and interferon (IFN)-gamma measured in the supernatant of stimulated cultured blood mononuclear cells did not change in the BCG group (10.8 +/- 2.3 vs. 17.9 +/- 5.7 pg/ml, and 348.6 +/- 118.0 vs. 354.8 +/- 139.0 pg/ml, respectively), while in the control group IL-4 increased (from 6.7 +/- 1.3 to 16.1 +/- 6.0 pg/ml, p < 0.05), and IFN-gamma decreased (from 279.9 +/- 82.1 to 232.1 +/- 109.6 pg/ml, p = 0.01). In comparison with their initial status, most patients maintained the same asthma severity and the same proportion of emergency room visits at the end of the study. The proportion of those in whom asthma improved or worsened was the same in both groups. We concluded that, contrary to the common hypothesis, BCG vaccination in asthmatic children was unable to cause a long-term reinforcement of Th(1) response, although it could avoid the increased Th(2) response observed in control patients.

Spatial indoor radon distribution in Mexico City

We present a spatial analysis of residential radon concentrations in the Mexico City Metropolitan Area, which we intend to use to assign radon exposure in an ongoing case-control study. As part of a probabilistic household survey, carried out between May and June 1999, 501 dwellings were selected for indoor placement of solid state nuclear track detectors (LR 115) in a cup array over a period of approximately 90 days. As part of the sampling design, the city was grid partitioned into nine zones and a sample of dwellings was selected in each zone. All zones were simultaneously surveyed. The stratified sampling design allowed us to obtain radon geometric means, adjusted for household characteristics, week of detector placement and number of days of measurement for these zones. Additionally, adjusted geometric means were estimated for the 100 census tracts surveyed and this information was used to obtain a more detailed spatial distribution of residential radon levels through kriging interpolation and surface contouring. Radon levels depended on the room of placement, the floor level and the ventilation habits but not on building materials. Regarding the city zone, the highest adjusted geometric mean was found in the southwest (136 Bqm(-3)), where 46% of the households had an estimated radon level in excess of 200 Bqm(-3). In the rest of the city, the geometric mean concentration ranged between 41 and 98 Bqm(-3). A more detailed spatial distribution showed that, in general, most of the eastern and middle zones of the city had estimated radon geometric means below 74 Bqm(-3), while the western ones had geometric means above this concentration. Very high geometric means, exceeding 111 Bqm(-3) and even reaching 288 Bqm(-3), are estimated for some areas located in the southern and western zones of Mexico City. The obtained spatial distribution shows that the areas with very high estimated residential radon concentrations are close to inactive volcanic mountains. We believe that the geo-statistical techniques, we have used, offer reasonably good estimates of the average spatial residential radon distribution in Mexico City under average ventilation in homes. The use of this indirect approach for radon exposure measurement in epidemiological studies is an inexpensive alternative to direct radon exposure measurement but may be subject to non-differential misclassification error. The effect of such error on the detection of a real increase in lung cancer risk from indoor radon remains to be determined.

[Epidemiologic panorama of cancer mortality in the Mexican Institute of Social Security: 1991-1995]

OBJECTIVE

This paper describes the global cancer mortality and the specific mortality patterns for the main neoplasms among adult members of the Mexican Institute of Social Security (IMSS).

MATERIAL AND METHODS

Using official death certificates and information about the population of the IMSS members during 1991-1995, national and regional annual global cancer mortality as well as specific mortality rates for the 10 most important malignant neoplasms by sex were estimated among people older than 20 years of age. The trends for these neoplasms during the study period were estimated by means of Poisson regression. The rate differences in specific cancer mortality by region and sex, for the two major neoplasms, were calculated subtracting specific regional rates from the respective national rate in 1995.

RESULTS

The global mortality rate for cancer among men increased from 76.2 in 1991 to 94.8 x 100000 IMSS' members in 1995; and among women from 85.6 to 105.8 x 100000 IMSS' members, representing an increment of 24.4 and 24% men and women, respectively, during the study period. Among men, neoplasm of kidney, leukemia, pancreas, prostate and lung showed the major increment; among women, neoplasm of colon, breast, pancreas, leukemia and liver showed the most significant increment.

CONCLUSIONS

In the IMSS it is necessary the integration of a population based cancer registry. The registry will play a main role in disease surveillance and control; will give basic information over incidence and temporal variation, and could be the main source of information for epidemiologic research, as well as planning and evaluation of the quality of medical attention services such as prevention and early diagnosis and treatment.

Bias from nondifferential misclassification in case-control studies with three exposure levels

In case-control studies with three exposure levels where disease risk is associated with exposure, the direction of bias in the odds ratios (ORs) from nondifferential misclassification depends on the risk level, misclassification rates, and exposure distributions. To extend these generalizations, we present a graphical analysis of bias from nondifferential misclassification assuming linear and nonlinear monotonic increasing exposure-risk patterns. In both middle and upper exposure levels, bias is usually toward the null, increasing in magnitude as the misclassification rates increase and as the skewness of the exposure distribution increases. In the middle exposure level, bias away from the null may occur when the misclassification rate is low in the reference level and moderate to high in the upper exposure level, and risk increases with exposure. Bias away from the null does not occur in the upper exposure level. In both excess risk levels, crossover bias (that is, a reversal of the OR) may occur when exposure classification is worse than chance. The magnitude of bias away from the null is constrained by the unbiased OR of the upper exposure level, whereas that of crossover bias is constrained by the inverse of the unbiased OR of the upper exposure level.

[Strategy for controlling poliomyelitis in Mexico: greater vaccination coverage of children less than 1 year of age]

In spite of the widespread use of oral poliovirus vaccine, some countries have not achieved an optimal control of poliomyelitis. According to Sabin, this fact is due to a lack of immunization coverage of children under one year of age. In this study, the relationship between the general morbidity rate for polio and vaccination coverage of children under one year of age, in people protected by the Mexican Institute of Social Security, is analyzed. There is a negative correlation between these two variables: the lesser the coverage, the greater the rates. There is also a correlation between the rate of polio and the rate of polio for the year prior to each of the years of the study period. In a multiple regression model, both the coverage and the rate for the previous year were significantly correlated with the rate of polio. In order to get an optimum control of this disease, it is advantageous to consider that it is not enough to increase the coverage but that this coverage must be opportune, i.e., in the first year of life.

[Evaluation of epidemiological articles published in 2 journals in the area of public health]

The main aim of this study was to assess the quality and quantity of the Mexican epidemiologic production published in two journals: Salud Pública de México (SPM) and Boletín de la Oficina Sanitaria Panamericana (BOSP). A previously accepted criterion was used to qualify a paper as an epidemiologic work. The period of study was eleven years (1975-1985) with 89 classified paper as "epidemiologic reports" (36 of BOSP and 53 of SPM). The variables included: original or revision's report; epidemiologic design; measures employed (frequency, association or potential impact); condition (contagious diseases, chronic-degenerative diseases or physiologic status); use of prevalent cases, incident cases or deaths; internal and external validity; bias' recognition; and number of references. Among the results that stand out are the proportion of cross-sectional designs (51.75), the weight for communicable diseases (36%), the detection of potential bias (65.7%) and the reports without references (30%). The discussion is centered in the main implications of these results when they are used to make decisions in the planning, operation and assessment of health services and in the generation of new epidemiologic knowledge.

[Differential mortality by sex. Causes and behavior of respiratory and gastroenteric infections in Mexico]

The differential in mortality by sex has not been broadly studied in Mexico. In this work mortality by sex in under one year old children and infants by federal entity for the main infectious diseases during 1980-1982 was analyzed. The results showed that the rate of mortality by sex (RMS) for under one year old children was higher than one, which means that there is a male over-mortality for that group of age. In the one to four year old children group, there were three entities that showed over-mortality among women. The analysis of the proportional mortality revealed that 40 to 50 percent of deaths in under one year old children were due to gastroenteral and respiratory infections. The probable causes of the male over-mortality observed and the need to determine the regional patterns of mortality are also discussed.