Lifestyle factors, direct and indirect costs for a Brazilian airline company

OBJECTIVE: To analyze lifestyle risk factors related to direct healthcare costs and the indirect costs due to sick leave among workers of an airline company in Brazil. METHODS: In this longitudinal 12-month study of 2,201 employees of a Brazilian airline company, the costs of sick leave and healthcare were the primary outcomes of interest. Information on the independent variables, such as gender, age, educational level, type of work, stress, and lifestyle-related factors (body mass index, physical activity, and smoking), was collected using a questionnaire on enrolment in the study. Data on sick leave days were available from the company register, and data on healthcare costs were obtained from insurance records. Multivariate linear regression analysis was used to investigate the association between direct and indirect healthcare costs with sociodemographic, work, and lifestyle-related factors. RESULTS: Over the 12-month study period, the average direct healthcare expenditure per worker was US$505.00 and the average indirect cost because of sick leave was US$249.00 per worker. Direct costs were more than twice the indirect costs and both were higher in women. Body mass index was a determinant of direct costs and smoking was a determinant of indirect costs. CONCLUSIONS: Obesity and smoking among workers in a Brazilian airline company were associated with increased health costs. Therefore, promoting a healthy diet, physical activity, and anti-tobacco campaigns are important targets for health promotion in this study population.

The influence of lifestyle and gender on sickness absence in brazilian workers

Background: Despite an increasing body of knowledge concerning gender and lifestyle factors as determinants of sickness absence in well-developed countries, the relationship between these variables has not been elucidated in emerging economic power countries, where the burden of non-communicable diseases is particularly high. This study aimed to analyze the relationships among lifestyle-related factors and sick leave and to examine whether gender differences in sickness absence can be explained by differences in socio-demographic, work and lifestyle-related factors among Brazilian workers. Methods: In this longitudinal study with a one year follow-up among 2.150 employees of a Brazilian airline company, sick leave was the primary outcome of interest. Independent variables collected by interview at enrolment in the study were gender, age, educational level, type of work, stress, and lifestyle-related factors (body mass index, physical activity and smoking). In addition, the risk for coronary heart disease was determined based on measurement of blood pressure, total cholesterol and glucose levels. The total number of days on sick leave during 12 months follow-up was available from the company register. Logistic regression analysis was used to determine the influence of socio-demographic, type of work and lifestyle-related factors on sick leave. Results: Younger employees, those with lower educational level, those who worked as air crew members and those with higher levels of stress were more likely to have sick leave. Body mass index and level of physical activity were not associated with sick leave. After adjustment by socio-demographic variables, increased odds for 10 or more days of sick leave were found in smokers (OR = 1.51, CI = 1.05-2.17), and ex-smokers (OR = 1.45, CI = 1.01-2.10). Women were more likely to have 10 or more days of sick leave. Gender differences were reduced mainly when adjusted for type of work (15%) and educational level (7%). Conclusions: The higher occurrence of sick leave among women than among men was partly explained by type of work and educational level. Our results suggest that type of work, a stressful life, and smoking are important targets for health promotion in this study population

Prevalência de sintomas do climatério em mulheres dos meios rural e urbano no Rio Grande do Norte, Brasil

OBJETIVO: avaliar a sintomatologia climatérica e fatores relacionados entre mulheres dos meios urbano e rural do Rio Grande do Norte. MÉTODOS: estudo transversal, descritivo, envolvendo casuística de 261 mulheres climatéricas residentes em Natal e Mossoró (grupo urbano; n=130) e Uruaçu, em São Gonçalo do Amarante (grupo rural; n=131). A sintomatologia climatérica foi avaliada pelo Índice Menopausal de Blatt-Kupperman (IMBK) e Escala Climatérica de Greene (ECG). A análise estatística constou de comparações das medianas dos escores entre os grupos e regressão logística. Defi niram-se como “muito sintomáticas” as pacientes com escores ≥20, para ambos instrumentos (variável dependente). As variáveis independentes foram: idade, procedência, alfabetização, obesidade e prática de atividade física. RESULTADOS: o grupo urbano apresentou escores signifi cativamente superiores ao grupo rural, tanto para o IMBK (medianas de 26,0 e 17,0, respectivamente; p<0,0001), quanto para a ECG (medianas de 27,0 e 16,0, respectivamente; p<0,0001). Na amostra total, evidenciou-se que 56,3% (n=147) das mulheres foram classifi cadas como “muito sintomáticas”. Na comparação intergrupos, essa prevalência foi signifi cativamente mais elevada nas mulheres urbanas em relação às rurais (79,2 e 33,6%, respectivamente; p<0,05). Pela análise de regressão logística, evidenciou-se que a chance de pertencer ao grupo defi nido como “muito sintomáticas” foi maior para mulheres do meio urbano [odds ratio ajustado (OR)=7,1; 95% intervalo de confi ança a 95% (IC95%)=3,69-13,66] e alfabetizadas (OR=2,19; IC95%=1,16-4,13). A idade superior a 60 anos associou-se com menor chance de ocorrência de sintomas signifi cativos (OR=0,38; IC95%=0,17-0,87). CONCLUSÕES: a prevalência de sintomas climatéricos signifi cativos é menor em mulheres do meio rural, demonstrando que fatores socioculturais e ambientais estão fortemente relacionados ao surgimento dos sintomas climatéricos em nossa população.___________________________________ABSTRACT PURPOSE: to evaluate climacteric symptoms and related factors in women living in rural and urban areas of Rio Grande do Norte, Brazil. METHODS: a cross-sectional study involving 261 women in the climacteric was performed. A total of 130 women from Natal and Mossoró (urban group) and 131 from Uruaçu, in São Gonçalo do Amarante (rural group), were studied. Climacteric symptoms were assessed by the Blatt-Kupperman Menopausal Index (BKMI) and Greene Climacteric Scale (GCE). Statistical analysis involved comparison of median between groups and logistic regression analysis. Patients were defi ned as “very symptomatic” when the climacteric score was ≥20 for both questionnaires (dependent variable). Independent variables were: age, living area, schooling, obesity and physical activity. RESULTS: the urban group had signifi cantly higher scores than those of the rural group, both for BKMI (median of 26.0 and 17.0, respectively; p<0.0001) and for GCE (median of 27.0 and 16.0, respectively; p<0.0001). For the entire sample, a total of 56.3% (n=147) of the women were classifi ed as “very symptomatic”. This prevalence was signifi cantly higher in urban than in rural women (79.2 and 33.6%, respectively; p<0.05). Logistic regression analysis showed that the likelihood of belonging to the group defi ned as “very symptomatic” was greater for urban women [adjusted odds ratio (OR)=7.1; confi dence interval at 95% (95%CI)=3.69-13.66] who were literate (OR=2.19; 95%CI=1.16- 4.13). Individuals over the age of 60 years had less chance of having signifi cant symptoms (OR=0.38; 95%CI=0.17-0.87). CONCLUSIONS: the prevalence of signifi cant climacteric symptoms is less in women from a rural environment, showing that sociocultural and environmental factors are strongly related to the appearance of climacteric symptoms in our population

A utilização de serviços odontológicos entre crianças e fatores associados em Sobral, Ceará, Brasil

NORO, L. R. A. et al. A utilização de serviços odontológicos entre crianças e fatores associados em Sobral, Ceará, Brasil. Cad. Saúde Pública, v. 24, n. 7, p. 1509-1516. 2008. ISSN 0102-311X.

Uso da internet no setor de hotelaria de Recife-PE

A Internet é uma tecnologia que revolucionou o mundo, criando novas formas de interação entre pessoas, organizações e negócios. O setor hoteleiro é um segmento que muito tem se beneficiado dos serviços suportados pela Internet. O objetivo do estudo é identificar os diferentes fatores que influenciam ao uso da Internet sob três dimensões: individual, organizacional e ambiental. Um modelo conceitual foi postulado contendo nove variáveis independentes sobre duas variáveis dependentes, relativas ao padrão de uso da Internet. Os dados foram coletados junto a 52 hotéis localizados no litoral do Recife – PE. O resultado da análise inferencial dos dados mostrou um padrão diferenciado de uso da Internet nos hotéis de pequeno, médio e grande porte e como os fatores acima descritos podem ser mais bem explorados a fim de se atingir um eficiente padrão de uso, aumentando suas posições competitivas. Baseadas na análise e resultados obtidos do estudo, são esboçadas algumas recomendações e implicações para futuras pesquisas. ABSTRACT:The Internet technology has revolutionized the world, creating new forms of interaction among people, organizations and businesses. The hotel sector has reaped many benefits from services supported by the Internet. The object of this study is to explore different factors that influence the adoption of the Internet in three areas: individual, organizational and environment. A conceptual framework was advanced containing nine independent variables and two dependent variables related to the usage of the Internet. Data was collected from 52 hotels located along the coast of Recife, PE, Brazil. Analysis of the data has demonstrated the Internet use in small, medium and large size hotels. Some attributes of the Internet usage could be better utilized by owners and managers in order to achieve a more efficient pattern of use, improving their competitive position. Based on the findings obtained from the study, some recommendations and implications for future research are advanced

Fatores que influenciam a aceitação de práticas avançadas de gestão de segurança da informação: um estudo com gestores públicos estaduais no Brasil

This study examines the factors that influence public managers in the adoption of advanced practices related to Information Security Management. This research used, as the basis of assertions, Security Standard ISO 27001:2005 and theoretical model based on TAM (Technology Acceptance Model) from Venkatesh and Davis (2000). The method adopted was field research of national scope with participation of eighty public administrators from states of Brazil, all of them managers and planners of state governments. The approach was quantitative and research methods were descriptive statistics, factor analysis and multiple linear regression for data analysis. The survey results showed correlation between the constructs of the TAM model (ease of use, perceptions of value, attitude and intention to use) and agreement with the assertions made in accordance with ISO 27001, showing that these factors influence the managers in adoption of such practices. On the other independent variables of the model (organizational profile, demographic profile and managers behavior) no significant correlation was identified with the assertions of the same standard, witch means the need for expansion researches using such constructs. It is hoped that this study may contribute positively to the progress on discussions about Information Security Management, Adoption of Safety Standards and Technology Acceptance Model

Os efeitos das reclamações online na lealdade dos consumidores: um estudo experimental

In an environment of constant change, technological developments, market competition and more informed consumers, the search for a lasting relationship through the conquest of loyalty has become the objective of companies. However, several authors suggest that this loyalty can be affected by negative comments available on the internet. Therefore, this dissertation has as objective to examine if the complaints are available on the internet impact the loyalty to a brand of mobile phone. The research used as the basis the Expanded NCSB model suggest by Johnson et al. (2001), studying five prominent drives of loyalty: image/brand reputation, affective commitment, calculative commitment, perceived value and trust, beyond the satisfaction construct as moderator variable. The research method adopted was the experimental design which included 285 undergraduate students, with the trial which included 285 undergraduate students, with the field study of the mobile industry, specifically, the brands of cell phones. The research approach was quantitative and methods were descriptive statistics, factor analysis, cluster analysis, linear regression and non-parametric test of Wilcoxon for data analysis. Of the 16 hypothesis stemmed from the research model proposed, 12 were confirmed. The results showed that the complaint available on the internet, here represented by the available on the site Reclame Aqui, may impact consumer perceptions about brand loyalty, as well as its antecedents, being that these complaints can affect all the consumers, regardless of historical satisfaction with the brand. It also noted the positive relationship between the independent variables trust, image/brand reputation, perceived value, affective commitment and calculative commitment and the dependent variable - loyalty, even when considering the data obtained after exposure to the complaint. However, no unanimous conclusion that the relationship between these variables was strongest in the group with satisfactory experience. At the first moment of the research, the trust was the most important variable for the formation of loyalty. However, after exposure to treatment, the image/brand reputation, was more relevant. Contributions of the study, limitations and recommendations for future researches are approached in the present investigation

Encapsulation of Local Anesthetic Bupivacaine in Biodegradable Poly(DL-lactide-co-glycolide) Nanospheres: Factorial Design, Characterization and Cytotoxicity Studies

Local anesthetic agents cause temporary blockade of nerve impulses productiong insensitivity to painful stimuli in the area supplied by that nerve. Bupivacaine (BVC) is an amide-type local anesthetic widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. in this study, we prepared and characterized nanosphere formulations containing BVC. To achieve these goals, BVC loaded poly(DL-lactide-co-glycolide) (PLGA) nanospheres (NS) were prepared by nanopreciptation and characterized with regard to size distribution, drug loading and cytotoxicity assays. The 2(3-1) factorial experimental design was used to study the influence of three different independent variables on nanoparticle drug loading. BVC was assayed by HPLC, the particle size and zeta potential were determined by dynamic light scattering. BVC was determined using a combined ultrafiltration-centrifugation technique. The results of optimized formulations showed a narrow size distribution with a polydispersivity of 0.05%, an average diameter of 236.7 +/- 2.6 nm and the zeta potential -2.93 +/- 1,10 mV. In toxicity studies with fibroblast 3T3 cells, BVC loaded-PLGA-NS increased cell viability, in comparison with the effect produced by free BVC. In this way, BVC-loaded PLGA-NS decreased BVC toxicity. The development of BVC formulations in carriers such as nanospheres could offer the possibility of controlling drug delivery in biological systems, prolonging the anesthetic effect and reducing toxicity.

Estado nutricional antropométrico, perfil lipídico e consumo alimentar como fatores de risco para doença cardiovascular em adolescentes

The dyslipidemia and excess weight in adolescents, when combined, suggest a progression of risk factors for cardiovascular disease (CVD). Besides these, the dietary habits and lifestyle have also been considered unsuitable impacting the development of chronic diseases. The study objectives were: (1) estimate the prevalence of lipid profile and correlate with body mass index (BMI), waist circumference (WC) and waist / height ratio (WHR) in adolescents, considering the maturation sexual, (2) know the sources of variance in the diet and the number of days needed to estimate the usual diet of adolescents and (3) describe the dietary patterns and lifestyle of adolescents, family history of CVD and age correlates them with the patterns of risk for CVD, adjusted for sexual maturation. A cross-sectional study was performed with 432 adolescents, aged 10-19 years from public schools of the Natal city, Brazil. The dyslipidemias were evaluated considering the lipid profile, the index of I Castelli (TC / HDL) and II (LDL / HDL) and non-HDL cholesterol. Anthropometric indicators were BMI, WC and WHR. The intake of energy, nutrients including fiber, fatty acids and cholesterol was estimated from two 24-hour recalls (24HR). The variables of lipid profile, anthropometric and clinical data were used in the models of Pearson correlation and linear regression, considering the sexual maturation. The variance ratio of the diet was calculated from the component-person variance, determined by analysis of variance (ANOVA). The definition of the number of days to estimate the usual intake of each nutrient was obtained by taking the hypothetical correlation (r) ≥ 0.9, between nutrient intake and the true observed. We used the principal component analysis as a method of extracting factors that 129 accounted for the dependent variables and known cardiovascular risk obtained from the lipid profile, the index for Castelli I and II, non-HDL cholesterol, BMI, and WC the WHR. Dietary patterns and lifestyle were obtained from the independent variables, based on nutrients consumed and physical activity weekly. In the study of principal component analysis (PCA) was investigated associations between the patterns of cardiovascular risk factors in dietary patterns and lifestyle, age and positive family history of CVD, through bivariate and multiple logistic regression adjusted for sexual maturation. The low HDL-C dyslipidemia was most prevalent (50.5%) for adolescents. Significant correlations were observed between hypercholesterolemia and positive family history of CVD (r = 0.19, p <0.01) and hypertriglyceridemia with BMI (r = 0.30, p <0.01), with the CC (r = 0.32, p <0.01) and WHR (r = 0.33, p <0.01). The linear model constructed with sexual maturation, age and BMI explained about 1 to 10.4% of the variation in the lipid profile. The sources of variance between individuals were greater for all nutrients in both sexes. The reasons for variances were  1 for all nutrients were higher in females. The results suggest that to assess the diet of adolescents with greater precision, 2 days would be enough to R24h consumption of energy, carbohydrates, fiber, saturated and monounsaturated fatty acids. In contrast, 3 days would be recommended for protein, lipid, polyunsaturated fatty acids and cholesterol. Two cardiovascular risk factors as have been extracted in the ACP, referring to the dependent variables: the standard lipid profile (HDL-C and non-HDL cholesterol) and "standard anthropometric index (BMI, WC, WHR) with a power explaining 75% of the variance of the original data. The factors are representative of two independent variables led to dietary patterns, "pattern 130 western diet" and "pattern protein diet", and one on the lifestyle, "pattern energy balance". Together, these patterns provide an explanation power of 67%. Made adjustment for sexual maturation in males remained significant variables: the associations between puberty and be pattern anthropometric indicator (OR = 3.32, CI 1.34 to 8.17%), and between family history of CVD and the pattern lipid profile (OR = 2.62, CI 1.20 to 5.72%). In females adolescents, associations were identified between age after the first stage of puberty with anthropometric pattern (OR = 3.59, CI 1.58 to 8.17%) and lipid profile (OR = 0.33, CI 0.15 to 0.75%). Conclusions: The low HDL-C was the most prevalent dyslipidemia independent of sex and nutritional status of adolescents. Hypercholesterolemia was influenced by family history of CVD and sexual maturation, in turn, hypertriglyceridemia was closely associated with anthropometric indicators. The variance between the diets was greater for all nutrients. This fact reflected in a variance ratio less than 1 and consequently in a lower number of days requerid to estimate the usual diet of adolescents considering gender. The two dietary patterns were extracted and the pattern considered unhealthy lifestyle as healthy. The associations were found between the patterns of CVD risk with age and family history of CVD in the studied adolescents

Eficácia do treinamento de força sobre parâmetros cardiovasculares e antropométricos em adultos sedentários

This study aimed to determine the influence of strength training (ST), in three weekly sessions over ten weeks, on cardiovascular parameters and anthropometric measurements. It is a before and after intervention trial, with a sample composed of 30 individuals. Participants were adults aged between 18 and 40 years, from both sexes and sedentary for at least three months previously. Tests were computed ergospirometry, CRP, PWV and body composition (dependent variables) before and after the experiment. Independent variables, age and sex, were considered in order to determine their influence on the dependent variablesevaluatedend. By comparing the initial cardiovascular parameters with those obtained after intervention in patients undergoing the ST proposed (a Student s t-test was conducted within each group for samples matched to parameters with normal distribution, while the Wilcoxin was applied for those without), there was no significant difference in PWV(p =0469) or PCR(p =0.247), but there was an increase in anaerobic threshold(AT) (p=0.004) and Maximal Oxygen Uptake(VO2max) (p =0.052). In regard to anthropometric measures, individuals significantly reduced their body fat percentage (p<0.001) and fat mass (p<0,001), as well as increasing lean mass (p<0.001). However, no changes were recorded in the waist-to-hip ratio (WHR) (p= 0.777), body mass (p=0.226) or body mass index (BMI) (p =0.212). Findings of this study lead us to believe that the proposed ST, and did not increase the VOP or PCR improves cardiorespiratory capacity and body composition. Devotees of this training can therefore safely enjoy all its benefits without risk to the cardiovascular system

Representações sociais sobre o acidente de trabalho em saúde

The aim of the present study was to identify the representational elements of workrelated accidents in the health field, as well as investigate their most frequent occurrences at a university hospital, seeking to understand the cognitive, affective and social elements subjacent to the work process involved in health. The analysis focused on 470 middle and senior support staff of this hospital, based on the theoretical-methodological support of the Social Representations Theory. A combination of the following instruments was used for data collection: a free wordassociation test, a questionnaire, an interview and a field journal. Evoc 2000 software was used to identify representational structure. Chi-square and Mann-Whitney tests, at a significance level of 5%, were performed to verify the association between the independent variables and the occurrence of work accidents. In addition, thematic content analysis and lexicographic analysis by ALCESTE software program were used to understand textual content. It was observed that social representations of work-related accidents in the health area are centered in the contamination category, while the categories of prevention and professional unpreparedness are found peripherally. There was a significant association between the existence of multiple employment, the use of personal protective equipment (PPI) during work, job satisfaction and the occurrence of work accidents. The conclusions indicate that perforating-cutting occupational accidents predominated in the hospital and that the representations of the subjects intertwined, with a traditional discourse of work accidents strongly present in Occupational Health. It is therefore suggested that certain subjective aspects related to culture, in terms of controlling work accidents, such as: management, process, organization and the increasing precariousness

Equação de regressão linear múltipla para estimativa do erro experimental

Este trabalho teve por objetivo estimar equações de regressão linear múltipla tendo, como variáveis explicativas, as demais características avaliadas em experimento de milho e, como variáveis principais, a diferença mínima significativa em percentagem da média (DMS%) e quadrado médio do erro (QMe), para peso de grãos. Com 610 experimentos conduzidos na Rede de Ensaios Nacionais de Competição de Cultivares de Milho, realizados entre 1986 e 1996 (522 experimentos) e em 1997 (88 experimentos), estimaram-se duas equações de regressão, com os 522 experimentos, validando estas pela análise de regressão simples entre os valores reais e os estimados pelas equações, com os 88 restantes, observando que, para a DMS% a equação não estimava o mesmo valor que a fórmula original e, para o QMe, a equação poderia ser utilizada na estimação. Com o teste de Lilliefors, verificou-se que os valores do QMe aderiam à distribuição normal padrão e foi construída uma tabela de classificação dos valores do QMe, baseada nos valores observados na análise da variância dos experimentos e nos estimados pela equação de regressão.

Influência da soma térmica e da chuva durante o desenvolvimento de laranjas-'Valência' e 'Natal' na relação entre sólidos solúveis e acidez e no índice tecnológico do suco

Este trabalho foi realizado com o objetivo de conhecer a influência que algumas variáveis meteorológicas exercem na razão entre sólidos solúveis totais e acidez total titulável (ratio) e no índice tecnológico dos frutos da primeira florada das laranjeiras-'Natal' e 'Valência', na região de Bebedouro-SP, mediante a utilização de métodos estatísticos de regressão. Foram utilizados dados de amostragens de rotina para o processamento industrial durante 4 anos, os quais permitiram desenvolver equações de regressão linear e quadrática, com a soma térmica (graus-dia) como variável independente, e de regressão múltipla, utilizando graus-dia e chuva como variáveis independentes. A equação de melhor ajuste para o índice tecnológico foi a quadrática, enquanto para o ratio a equação linear apresentou o melhor ajuste. A temperatura do ar, representada por graus-dia, foi a variável que exerceu maior influência nos indicadores de qualidade dos frutos.

Mortalidade infantil e condições socioeconômicas nas microrregiões do Nordeste Brasileiro

The study aims to answer the following question: what are the different profiles of infant mortality, according to demographic, socioeconomic, infrastructure and health care, for the micro-regions at the Northeast of Brazil? Thus, the main objective is to analyze the profiles or typologies associated mortality levels sociodemographic conditions of the micro-regions, in the year 2010. To this end, the databases of birth and death certificates of SIM and SINASC (DATASUS/MS), were taken from the 2010 population Census microdata and from SIDRA/IBGE. As a methodology, a weighted multiple linear regression model was used in the analysis in order to find the most significant variables in the explanation child mortality for the year 2010. Also a cluster analysis was performed, seeking evidence, initially, of homogeneous groups of micro-regions, from of the significant variables. The logit of the infant mortality rate was used as dependent variable, while variables such as demographic, socioeconomic, infrastructure and health care in the micro-regions were taken as the independent variables of the model. The Bayesian estimation technique was applied to the database of births and deaths, due to the inconvenient fact of underreporting and random fluctuations of small quantities in small areas. The techniques of Spatial Statistics were used to determine the spatial behavior of the distribution of rates from thematic maps. In conclusion, we used the method GoM (Grade of Membership), to find typologies of mortality, associated with the selected variables by micro-regions, in order to respond the main question of the study. The results points out to the formation of three profiles: Profile 1, high infant mortality and unfavorable social conditions; Profile 2, low infant mortality, with a median social conditions of life; and Profile 3, median and high infant mortality social conditions. With this classification, it was found that, out of 188 micro-regions, 20 (10%) fits the extreme profile 1, 59 (31.4%) was characterized in the extreme profile 2, 34 (18.1%) was characterized in the extreme profile 3 and only 9 (4.8%) was classified as amorphous profile. The other micro-regions framed up in the profiles mixed. Such profiles suggest the need for different interventions in terms of public policies aimed to reducing child mortality in the region

Response surface models to predict broiler performance and applications for economic analysis

A study was carried out to elaborate response surface models using broiler performance data recovered from literature in order to predict performance and elaborate economic analyses. Nineteen studies published between 1995 and 2005 were retrieved using the systematic literature review method. Weight gain and feed conversion data were collected from eight studies that fulfilled the pre-established inclusion criteria, and a response surface model was adjusted using crude protein, environmental temperature, and age as independent variables. The models produced for weight gain (r² = 0.93) and feed conversion (r² = 0.85) were accurate, precise, and not biased. Protein levels, environmental temperature and age showed linear and quadratic effects on weight gain and feed conversion. There was no interaction between protein level and environmental temperature. Age and crude protein showed interaction for weight gain and feed conversion, whereas interaction between age and temperature was detected only for weight gain. It was possible to perform economic analyses to determine maximum profit as a function of the variables that were included in the model. It was concluded that the response surface models are effective to predict the performance of broiler chickens and allow the elaboration of economic analyses to optimize profit.