BackgroundCross-sectional studies with binary outcomes analyzed by logistic regression are frequent in the epidemiological literature. However, the odds ratio can importantly overestimate the prevalence ratio, the measure of choice in these studies. Also, controlling for confounding is not equivalent for the two measures. In this paper we explore alternatives for modeling data of such studies with techniques that directly estimate the prevalence ratio.MethodsWe compared Cox regression with constant time at risk, Poisson regression and log-binomial regression against the standard Mantel-Haenszel estimators. Models with robust variance estimators in Cox and Poisson regressions and variance corrected by the scale parameter in Poisson regression were also evaluated.ResultsThree outcomes, from a cross-sectional study carried out in Pelotas, Brazil, with different levels of prevalence were explored: weight-for-age deficit (4%), asthma (31%) and mother in a paid job (52%). Unadjusted Cox/Poisson regression and Poisson regression with scale parameter adjusted by deviance performed worst in terms of interval estimates. Poisson regression with scale parameter adjusted by χ2 showed variable performance depending on the outcome prevalence. Cox/Poisson regression with robust variance, and log-binomial regression performed equally well when the model was correctly specified.ConclusionsCox or Poisson regression with robust variance and log-binomial regression provide correct estimates and are a better alternative for the analysis of cross-sectional studies with binary outcomes than logistic regression, since the prevalence ratio is more interpretable and easier to communicate to non-specialists than the odds ratio. However, precautions are needed to avoid estimation problems in specific situations.

The hypothesis of similarity between the extreme degrees of social distribution, translated by maternal education level in relation to the proportion of low birth weight, was not confirmed.

OBJECTIVE:To assess female homicide rates due to aggression according to sociodemographic and health indicators. METHODS: RESULTS:The standardized female homicide rate due to aggression was 4.1/100,000 during the study period. After adjustment, three variables remained signifi cantly associated with female homicides: birth rate (p = 0.072), percentage of Evangelicals (p = 0.019) and male homicides due to aggression (p < 0.001). The model had a predictive power of 69% (r2 = 0.699). The Brazilian states of Espírito Santo, Pernambuco, Mato Grosso, Rio de Janeiro, Rondônia, Alagoas, Mato Grosso do Sul, Roraima e Amapá showed the highest rates during the study period. CONCLUSIONS:The female homicide rates due to aggression were high in Brazil and varied by region. The association with male homicides due to aggression stresses the importance of reducing structural violence to protect women against violence. DESCRIPTORS:

This study analyses the relationship between femicides and indicators of socio-eco-

Background: In Brazil, treatment of panic disorder is most frequently initiated with pharmacotherapy, but only half of the patients can be expected to be panic free after medication. Studies have suggested that individual or group cognitive-behavior therapy (CBT) is an effective treatment strategy for panic patients who have failed to respond to pharmacotherapy. Methods: Thirty-two patients diagnosed with panic disorder with agoraphobia having residual symptoms despite being on an adequate dose of medication were treated with 12 weeks of group CBT. The outcome was evaluated for panic frequency and severity, generalized anxiety, and global severity. Comorbid conditions, a childhood history of anxiety, and defense mechanism styles were assessed as potential predictors of treatment response. Results: Twenty-nine patients completed the 12-week protocol. Treatment was associated with significant reductions in symptom severity on all outcome measures (p < 0.001). Patients with depression had a poorer outcome of the treatment (p = 0.01) as did patients using more neurotic (p = 0.002) and immature defenses (p = 0.05). Conclusion: Consistent with previous reports, we found that CBT was effective for our sample of treatment-resistant patients. Among these patients, depression as well as neurotic defense style was associated with a poorer outcome. The use of CBT in Brazil for treatment-resistant and other panic patients is encouraged.

The Institute of Medicine updated guidelines for gestational weight gain in 2009, with no special recommendations for gestational diabetes. Our objectives were to describe the prevalence of weight gain adequacy and their association with adverse pregnancy outcomes in gestational diabetes. We searched MEDLINE, EMBASE, COCHRANE and SCOPUS. We calculated the pooled prevalence of gain adequacy and relative risks for pregnancy outcomes within Institute of Medicine categories. Thirty-three studies/abstracts (88,599 women) were included. Thirty-one studies provided data on the prevalence of weight gain adequacy; it was adequate in 34% (95% CI: 29-39%) of women, insufficient in 30% (95% CI: 27-34%) and excessive in 37% (95% CI: 33-41%). Excessive gain was associated with increased risks of pharmacological treatment, hypertensive disorders of pregnancy, caesarean section, large for gestational age and macrosomic babies, compared to adequate or non-excessive gain. Weight gain below the guidance had a protective effect on large babies (RR: 0.71; 95% CI: 0.56-0.90) and macrosomia (RR 0.57; 95% CI 0.40-0.83), and did not increase the risk of small babies (RR 1.40; 95% CI 0.86-2.27). Less than recommended weight gain would be beneficial, while effective prevention of excessive gain is of utmost importance, in gestational diabetes pregnancies. Nevertheless, no ideal range for weight gain could be established.

Obesity has been pointed out as a risk factor for higher prevalence of asthma and asthma-related symptoms in adolescents. The objective was to evaluate the relationship between the prevalence of asthma and obesity in adolescents living in Santa Maria and surroundings (state of Rio Grande do Sul, southern Brazil), applying the International Study of Asthma and Allergies in Childhood (ISAAC) protocol. A total of 4,010 of 6,123 schoolchildren, 13 to 14 years of age, enrolled in the ISAAC phase III protocol (asthma core questionnaire) and were nutritionally evaluated: height, weight, and triceps skinfold (TSF) measurements. Prevalence of asthma (wheeze in the last 12 months) and prevalence of severe asthma (two or more affirmative responses to: more than 4 acute attacks of asthma, speech disturbance, sleep disturbance, wheezing with exercise) were evaluated and compared according to their nutritional status: obese and non-obese. Obese adolescents were defined by body mass index (BMI, in kg/m(2)) > or =85th percentile and TSF > or =85th percentile. Obese and non-obese groups were compared for prevalence of asthma and asthma severity using the Chi-square test and odds ratio (OR) with 95% confidence interval. Analyzing all adolescents, we observed a significant positive relationship between the prevalence of obesity and affirmative responses to "wheeze ever" (OR = 1.28; 95% CI 1.08-1.52), "wheezing with exercise" (OR = 1.36; 95% CI 1.11-1.66), "asthma ever" (OR = 1.29; 95% CI 1.03-1.62), and severe asthma (OR = 1.55; 95% CI 1.12-2.14). Among the boys, there was a significant positive association between obesity and "wheeze ever" (OR = 1.49; 95% CI 1.13-1.86). In girls, there was a significant positive relationship with "asthma ever" (OR = 1.38; 95% CI 1.01-1.88) and "wheezing with exercise" (OR = 1.36; 95% CI 1.11-1.66). This cross-sectional study with adolescents living in the southern region of Brazil showed that there is a positive association between obesity and prevalence of asthma symptoms and asthma severity, a finding mainly confined to girls.

BackgroundLow birth weight (LBW) newborns present different health outcomes when classified in different birth weight strata. This study evaluated the relationship of birth weight with Infant mortality (IM) through the influence of biological, social, and health care factors in a time series.MethodsRetrospective cohort study with data collected from Information Systems (Live Births and Mortality). The mortality trends were performed for each birth weight stratum: extremely low, < 1000 g; very low, 1000–1499 g; low, 1500–2499 g; insufficient, 2500–2999 g; adequate, 3000–3900 g; and macrosomia, > 4000 g. Chi-square tests analyzed IM rates. Sequential Poisson regression analyzed the impact of the determinant factors.ResultsA total of 277,982 newborns were included in the study and 2088 died before their first year. There was a tendency for a decrease in mortality in all strata of weight. With the exception of macrosomics, all other strata had a higher risk for IM when compared with adequate birth weight. Extremely LBW newborns presented higher risk for mortality when born in a public hospital. A higher percentage of infant deaths were associated with lower maternal age and lower schooling for all strata. Prenatal care with less than three visits demonstrated a risk for IM in low, insufficient, and adequate birth weight strata. The cesarean section was a protective factor for IM in Extremely and Very LBW strata and it was a risk factor in adequate birth weight stratum.ConclusionsLBW had a greater association with IM, especially those children of younger mothers and those born in public hospitals.