Biomedical subjects

Nilza Nunes da Silva

Publications and source records attributed to Nilza Nunes da Silva.

5 recordsLinked to original sources

PubMed2005

[Surveillance of risk factors for chronic diseases through telephone interviews].

OBJECTIVE: To describe methods and initial findings of a surveillance system of risk factors for chronic non-communicable diseases (CNCDs) based on telephone interviews. METHODS: Interviews undertaken in a random sample of the adult population of the Municipality of Sao Paulo living in households with telephone. Sampling was done in two steps and included the random selection of households and the random selection of the household member to be interviewed. The system's questionnaire investigated demographic and socioeconomic characteristics, food consumption and physical activity patterns, smoking, consumption of alcoholic beverages, recalled weight and height and reported medical diagnoses of hypertension and diabetes, among other topics. Prevalence estimates of selected risk factors for CNCDs were calculated for the adult population with telephone and for the city's entire adult population. In this last case, we applied sample weighting factors that took into account demographic and socioeconomic differences between the adult population with telephone and the entire adult population of the municipality. RESULTS: Strong differences between sexes were found for most risk factors: low consumption of fruit and vegetables, high consumption of alcohol and overweight were more frequent among men while sedentary lifestyle and hypertension were more frequent among women. Additional possibilities of stratification of risk factor prevalences allowed by the surveillance system are illustrated using age groups, schooling, and place of residence in the city. CONCLUSIONS: System performance was considered as good and was better than the performance observed in similar systems operating in developed countries when evaluated with basis on the representativeness and reliability of the estimates and on costs. The cost per concluded interview was eight times lower than the cost usually seen in similar systems in developed countries and four to eight times lower than the cost of traditional household surveys undertaken in the city of Sao Paulo.

Adult↗

PubMed2003

[Estimates from a complex survey].

OBJECTIVE: To evaluate the impact of sampling design and the effect of weighting on data from the 1996 Brazilian National Survey on Demography and Health. METHODS: Secondary data analysis was performed using a sample of 1,355 interviewed women of the state of São Paulo. The sampling design of the National Survey of Household Sampling (PNAD) was used as a reference, and the municipality as primary sampling unit. The ratio estimator and Taylor's approximation for variance were calculated using the primary sampling units and several modalities of weighting. The indicators used to evaluate precision and validity were confidence intervals, design effects (Deff) and biases. RESULTS: For the four procedures, the differences between upper and lower point estimates for prevalence were not greater than 10%. The differences on ranges of confidence intervals were less than 20%. Use of condom and hormone injection were the variables that showed design effects greater than 1.5 and biases greater than 0.20. CONCLUSIONS: According to the results, it could be said that the cluster sampling had an impact on the precision of the estimates for two out of six variables. The impact of weighting was not significant.

Bias↗

PubMed2003

[Master sample and geoprocessing: technologies for household surveys].

OBJECTIVE: To reduce cost and time associated with household sampling process and to assess the feasibility of shared use of address data file of census enumeration areas in several epidemiological surveys using updated information from the National Survey of Households (PNAD). METHODS: Address data file comprising 72 census enumeration areas was kept as primary sampling units for the city of S o Paulo. During the period 1995-2000, three distinct household samples were drawn using the two-stage cluster sampling procedure. Geographic Information System (GIS) technology allowed delimiting boundaries, blocks and streets for any primary sampling unit and printing updated maps for selected sub-samples. RESULTS: Twenty-five thousand dwellings made up the permanent address data file of the master sample. A cheaper and quicker selection of each sample, plus gathering information on demographic and topographical profiles of census enumeration areas were the main contribution of the study results. CONCLUSIONS: The master sample concept, integrated with GIS technology, is an advantageous alternative sampling design for household surveys in urban areas. Using the list of addresses from the PNAD updated yearly, although limiting its application to the most populated Brazilian cities, avoids the need of creating an independent sampling procedure for each individual survey carried out in the period between demographic censuses, and it is an important contribution for planning sampling surveys in public health.

Censuses↗

PubMed2003

[Prevalence of malnutrition among children in Embu, São Paulo State, Brazil, 1996-1997].

This paper focused on the nutritional profile of children in the municipality of Embu, São Paulo State, Brazil, in 1996-1997, to identify vulnerable population segments that require specific action by health services. The sample consisted of 320 children < or = 5 years of age distributed into four socioeconomic strata. The indices were expressed as z-scores: weight/age (W/A), height/age (H/A), and weight/height (W/H) to analyze the nutritional status, and the reference for normality was the NCHS curve. In all population strata and age groups, the height/age index was the most frequently affected, while the weight/height index had the fewest deficits. No statistically significant differences were observed in children's nutritional status between the four population strata or between the different age groups. Children with low birth weight showed the highest prevalence of deficits in all indices. In the municipality, the frequency of deficits were: H/A< 2z: 7.1%, W/H< 2z: 0.2%, and W/A< 2z: 2.9%. Height deficit can be used as an early warning, considering that loss observed over the course of years has future consequences.

Anthropometry↗

PubMed2003

[Prenatal and childbirth care equity in an area in Greater Metropolitan São Paulo, 1996].

A cross-sectional study was conducted to evaluate prenatal and childbirth care interviewing mothers of infants in the municipality of Embu (Greater Metropolitan São Paulo) in 1996, according to four socioeconomic strata. A door-to-door survey included a probabilistic sample consisting of 483 infants. In all strata more than 90% of the mothers had received prenatal care, but with late access in stratum 4 (residents of favelas, or slums). Breast examination during prenatal care, reported by only 60.8% of the mothers, was the worst single indicator of quality of prenatal care in the municipality. The outcome indicator - first prenatal consultation after the first trimester and total number of consultations less than six - was associated with maternal age (less than 20 years), low per capita family income (less than one minimum wage), and lack of private health plan. As for deliveries, 97.7% occurred in hospital, of which 32.5% by cesarean section, with the latter more frequent in private health care facilities (63.2%). No population segments were identified as being excluded from the health care system, but some indicators suggest greater deficiencies in socioeconomic stratum 4. These results have supported local health system managers in redefining health measures for the municipality.

Adult↗