National Demographic and Health Survey 2003 - Philippines

Abstract
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The 2003 National Demographic and Health Survey (NDHS) is a nationally representative sur­vey of 13,945 women age 15-49 and 5,009 men age 15-54. The main purpose of the 2003 NDHS is to provide policymakers and program managers with detailed information on fertility, family plan­ning, childhood and adult mortality, maternal and child health, and knowledge and attitudes related to HIV/AIDS and other sexually transmitted in­fections. The 2003 NDHS also collects high qual­ity data on family health: immunizations, preva­lence and treatment of diarrhea and other diseases among children under five, antenatal visits, assis­tance at delivery and breastfeeding.

The 2003 NDHS is the third national sample survey undertaken in Philippines under the aus­pices of the worldwide Demographic and Health Surveys program.

The 2003 Philippines National Demographic and Health Survey (NDHS) is designed to provide up­to-date information on population, family planning, and health to assist policymakers and program managers in evaluating and designing strategies for improving health and family planning services in the country. In particular, the 2003 NDHS has the following objectives:
- Collect data at the national level, which will allow the calculation of demographic rates and, particularly, fertility and under-five mortality rates.
- Analyze the direct and indirect factors that determine the level and trends of fertility. Indicators related to fertility will serve to inform plans for social and economic development.
- Measure the level of contraceptive knowledge and practice by method, urban-rural residence, and region.
- Collect data on knowledge and attitudes of women and men about sexually transmitted infections and HIV/AIDS and evaluate patterns of recent behavior regarding condom use.
- Collect high-quality data on family health, including immunizations, prevalence and treatment of diarrhea and other diseases among children under five, antenatal visits, assistance at delivery, and breastfeeding.

Geographic coverage
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National

Analysis unit
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- Household
- Women age 15-49
- Men age 15-54

Universe
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The population covered by the 1998 Phillipines NDS is defined as the universe of all females age 15-49 years, who are members of the sample household or visitors present at the time of interview and had slept in the sample households the night prior to the time of interview, regardless of marital status and all men age 15-54 living in the household.

Kind of data
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Sample survey data

Sampling procedure
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The 2003 NDHS is the first survey that used the new master sample created for household surveys on the basis of the 2000 Census of Population and Housing. The 2003 NDHS used one of the four replicates of the master sample. The sample was designed to represent the country as a whole, urban and rural areas, and each of the 17 administrative regions. In each region, a stratified, three-stage cluster sampling design was employed. In the first stage, 819 primary sampling units (PSUs) were selected with probability proportional to the number of households in the 2000 census. PSUs consisted of a barangay or a group of contiguous barangays. In the second stage, in each PSU, enumeration areas (EAs) were selected with probability proportional to the number of EAs. An EA is defined as an area with discernable boundaries consisting of about 150 contiguous households. All households in the selected EAs were listed in a separate field operation conducted May 7 through 21, 2003. In the third stage, from each EA, an average of 17 households was selected using systematic sampling.

Mode of data collection
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Face-to-face

Research instrument
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The 2003 NDHS used four questionnaires: a) Household Questionnaire, b) Health Module, c) Women's Questionnaire, and d) Men's Questionnaire. The content of the Women's Questionnaire was based on the MEASURE DHS+ Model “A” Questionnaire, which was developed for use in countries with high levels of contraceptive use. To modify the questionnaire to reflect relevant family planning and health issues in the Philippines, program input was solicited from Department of Health (DOH), Commission on Population (POPCOM), the University of the Philippines Population Institute (UPPI), the Food and Nutrition Research Institute (FNRI), the Philippine Health Insurance Corporation (PhilHealth), USAID, the National Statistics Coordination Board (NSCB), the National Economic and Development Authority (NEDA), the United Nations Children's Fund (UNICEF), and Dr. Mercedes B. Concepcion, professor emeritus at the University of the Philippines, as well as managers of USAID-sponsored projects in the Philippines. The questionnaires were translated from English into six major languages: Tagalog, Cebuano, Ilocano, Bicol, Hiligaynon, and Waray.

a) The Household Questionnaire was used to list all of the usual members and visitors in the selected households. Basic information collected for each person listed includes age, sex, education, and relationship to the head of the household. The main purpose of the Household Questionnaire was to identify women and men who were eligible for the individual interview. Information on characteristics of the household's dwelling unit, such as the source of water, type of toilet facilities, materials used for the floor of the house, and ownership of various durable goods, was also recorded in the Household Questionnaire. These items are indicators of the household's socioeconomic status.

b) The Health Module was aimed at apprising concerned agencies on the health status, practices, and attitude of the population. The module included the following topics:
- Health facility utilization
- Noncommunicable diseases
- Infectious diseases
-Traditional medicines, healing practices, and alternative health care modalities
- Health care financing -Environmental health.

c) The Women's Questionnaire was used to collect information from all women age 15-49. These women were asked questions on the following topics:
- Background characteristics (e.g., education, media exposure)
- Reproductive history
- Knowledge and use of family planning methods
- Fertility preferences
- Antenatal, delivery, and postnatal care
- Breastfeeding and infant feeding practices
- Vaccinations and childhood illnesses
- Marriage and sexual activity
- Woman's work and husband's background characteristics
- Infant's and children's feeding practices
- Childhood mortality
- Awareness and behavior regarding AIDS and other sexually transmitted infections
- Awareness and behavior regarding tuberculosis

d) The Men's Questionnaire was administered to all men age 15-54 living in every third household in the NDHS sample. The Men's Questionnaire collected much of the same information found in the Women's Questionnaire but was shorter because it did not contain questions on reproductive history, maternal and child health, and nutrition. Instead, men were asked about their knowledge and participation in health-seeking practices for their children.

Cleaning operations
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All completed questionnaires and the control forms were returned to the NSO Central Office in Manila for data processing, which consisted of manual editing, data entry and verification, and editing of computer-identified errors. An ad hoc group of seven regular employees of DSSD was created to work full time in the NDHS Data Processing Center. This group was responsible for the different aspects of NDHS data processing. There were 10 manual processors and 25 data encoders hired to process the data.

Manual editing started on July 15, 2003, and data entry started on July 21, 2003. The computer package program called CSPro (Census and Survey Processing System) was used for data entry, editing, and tabulation. To prepare the data entry programs, two NSO staff members spent three weeks in ORC Macro offices in Calverton, Maryland, in April and May 2003. Data processing was completed in October 29, 2003.

Response rate
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For the 2003 NDHS sample, 13,914 households were selected, of which 12,694 were occupied (Table). Of these households, 12,586 were successfully interviewed, yielding a household response rate of 99 percent. Household response rates are similar in rural areas and in urban areas (99 percent).

Among the households interviewed, 13,945 women were identified as eligible respondents, and interviews were completed for 13,633 women, yielding a response rate of 98 percent. In a subsample of every third household, 5,009 men were identified to be eligible for individual interview. Of these, 4,766 were successfully interviewed, yielding a response rate of 95 percent.

Sampling error estimates
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Sampling errors, on the other hand, can be evaluated statistically. The sample of respondents se­lected in the 2003 NDHS is only one of many samples that could have been selected from the same popu­lation, using the same design and expected size. Each of these samples would yield results that differ somewhat from the results of the actual sample selected. Sampling errors are a measure of the variability between all possible samples. Although the degree of variability is not known exactly, it can be estimated from the survey results.

A sampling error is usually measured in terms of the standard error for a particular statistic (e.g., mean, percentage), which is the square root of the variance. The standard error can be used to calculate confidence intervals within which the true value for the population can reasonably be assumed to fall. For example, for any given statistic calculated from a sample survey, the value of that statistic will fall within a range of plus or minus two times the standard error of that statistic in 95 percent of all possible samples of identical size and design.

If the sample of respondents had been selected as a simple random sample, it would have been possible to use straightforward formulas for calculating sampling errors. However, the 2003 NDHS sam­ple is the result of a multistage stratified design, and consequently, it was necessary to use more complex formulas. The computer software used to calculate sampling errors for the 2003 NDHS is the Integrated System for Survey Analysis (ISSA) Sampling Error Module. This module used the Taylor linearization method of variance estimation for survey estimates that are means or proportions. The Jackknife repeated replication method is used for variance estimation of more complex statistics, such as fertility and mortal­ity rates.

The Jackknife repeated replication method derives estimates of complex rates from each of sev­eral replications of the parent sample and calculates standard errors for these estimates using simple for­mulas. Each replication considers all but one cluster in the calculation of the estimates. Pseudo-independent replications are thus created. In the 2003 NDHS, there were 819 non-empty clusters; hence, 818 replications were created.

In addition to the standard error, ISSA computes the design effect (DEFT) for each estimate, which is defined as the ratio between the standard error using the given sample design and the standard error that would result if a simple random sample had been used. A DEFT value of 1.0 indicates that the sample design is as efficient as a simple random sample, while a value greater than 1.0 indicates that the increase in the sampling errors is due to the use of a more complex and less statistically efficient design. ISSA also computes the relative error and confidence limits for the estimates.

Sampling errors for the 2003 NDHS were calculated for selected variables considered to be of primary interest for the women's survey and for the men's survey. The results are presented in an ap­pendix to the Final Report for the country as a whole, for urban and rural areas, and for each of the 17 regions. For each vari­able, the type of statistic (mean, proportion, or rate) and the base population are given in Table B.1 of the Final Report. Ta­bles B.2 to B.21 present the value of the statistic (R), its standard error (SE), the number of unweighted cases (N) and weighted cases (WN), the design effect (DEFT), the relative standard error (SE/R), and the 95 percent confidence limits (R±2SE) for each variable. The DEFT is considered undefined when the standard error considering the simple random sample is zero (when the estimate is close to 0 or 1). In the case of the total fertility rate, the number of unweighted cases is not relevant, as there is no known un­weighted value for woman-years of exposure to childbearing.

The confidence interval (e.g., as calculated for children ever born to women age 40-49) can be in­terpreted as follows: the overall average from the national sample is 4.321, and its standard error is 0.065. Therefore, to obtain the 95 percent confidence limits, one adds and subtracts twice the standard error to the sample estimate (i.e., 4.32 ± 2 × 0.065). There is a high probability (95 percent) that the true average number of children ever born to all women age 40 to 49 is between 4.192 and 4.451.

Sampling errors were analyzed for the national sample of women and for two separate groups of estimates: 1) means and proportions and 2) complex demographic rates. The relative standard errors (SE/R) for the means and proportions range between 0.1 and 29.1 percent, with an average of 3.27 per­cent; the highest relative standard errors are for estimates of very low values (e.g., currently using male sterilization). If estimates of very low values (less than 10 percent) are removed, then the average drops to
1.81 percent. So in general, the relative standard error for most estimates for the country as a whole is small, except for estimates of very small proportions. The relative standard error for the total fertility rate is small (1.9 percent). However, for the mortality rates, the average relative standard error is much higher
(8.95 percent).

There are differentials in the relative standard error for the estimates of subpopulations. For ex­ample, for the variable “want no more children,” the relative standard errors as a percent of the estimated mean for the whole country and for the urban areas are 0.9 and 1.4 percent, respectively.

For the total sample, the value of the DEFT, averaged over all variables, is 1.167, which means that, because of multistage clustering of the sample, the average standard error is increased by a factor of
1.167 over that in an equivalent simple random sample.

Data appraisal
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Nonsampling errors are the results of mistakes made in implementing data collec­tion and data processing, such as failure to locate and interview the correct household, misunderstanding of the questions on the part of either the interviewer or the respondent, and data entry errors. Although numerous efforts were made during the implementation of the 2003 National Demographic and Health Survey (NDHS) to minimize this type of error, nonsampling errors are impossible to avoid and difficult to evaluate statistically.

摘要
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2003年全国人口与健康调查（NDHS）是一项针对13,945名15-49岁女性和5,009名15-54岁男性的全国代表性调查。2003年NDHS的主要目的是为政策制定者和项目管理者提供关于生育、家庭计划、儿童与成人死亡率、母婴健康以及与HIV/AIDS和其他性传播感染相关的知识与态度的详细信息。2003年NDHS还收集了关于家庭健康的优质数据：免疫接种、5岁以下儿童腹泻和其他疾病的流行和治疗、产前检查、分娩援助和母乳喂养。

2003年NDHS是菲律宾在全世界人口与健康调查计划支持下进行的第三次全国样本调查。

2003年菲律宾全国人口与健康调查（NDHS）旨在提供关于人口、家庭计划与健康的最新信息，以协助政策制定者和项目管理者评估和设计改善国家健康和家庭计划服务的策略。特别是，2003年NDHS具有以下目标：
- 收集国家级数据，以便计算人口统计指标，特别是生育率和5岁以下死亡率。
- 分析决定生育水平和发展趋势的直接和间接因素。与生育相关的指标将用于告知社会和经济发展的计划。
- 通过方法、城乡居住地和地区来衡量避孕知识的普及程度和实践水平。
- 收集关于女性和男性对性传播感染和HIV/AIDS的认知和态度的数据，并评估近期关于避孕套使用的行为模式。
- 收集关于家庭健康的优质数据，包括免疫接种、5岁以下儿童腹泻和其他疾病的流行和治疗、产前检查、分娩援助和母乳喂养。

地理覆盖范围
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全国

分析单元
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- 家庭
- 15-49岁女性
- 15-54岁男性

总体
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由1998年菲律宾NDS覆盖的人口被定义为所有15-49岁女性，无论婚姻状况，以及所有居住在户内的15-54岁男性，这些女性是样本家庭或访谈时的访客，并在访谈前夜睡在样本家庭中。

数据类型
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样本调查数据

抽样程序
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2003年NDHS是第一个使用基于2000年人口和住房普查的新主样本的家庭调查的普查。2003年NDHS使用了主样本的四个复制品之一。样本旨在代表整个国家，包括城市和农村地区，以及17个行政区域中的每一个。在每个区域，采用分层、三阶段聚类抽样设计。在第一阶段，根据2000年普查的家庭数量以概率比例选择了819个一级抽样单位（PSU）。PSU由一个barangay或一系列相邻的barangay组成。在第二阶段，在每个PSU中，根据EA的数量以概率比例选择了统计区域（EA）。EA是指具有可识别边界、大约由150个相邻家庭组成的一个区域。2003年5月7日至21日，对所有选定EA中的家庭进行了单独的现场操作，列出了所有家庭。在第三阶段，从每个EA中，使用系统抽样方法选择了平均17个家庭。

数据收集方式
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面对面

研究工具
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2003年NDHS使用了四份问卷：a）家庭问卷，b）健康模块，c）女性问卷和d）男性问卷。女性问卷的内容基于MEASURE DHS+模型“A”问卷，该问卷是为在避孕使用率较高的国家使用而开发的。为了修改问卷以反映菲律宾相关的家庭计划和健康问题，从卫生部门（DOH）、人口委员会（POPCOM）、菲律宾大学人口研究所（UPPI）、食品与营养研究所（FNRI）、菲律宾健康保险公司（PhilHealth）、USAID、国家统计协调委员会（NSCB）、国家经济和社会发展局（NEDA）、联合国儿童基金会（UNICEF）以及菲律宾大学荣誉退休教授Mercedes B. Concepcion，以及菲律宾USAID资助项目的管理者那里征求了项目输入。问卷被翻译成六种主要语言：他加禄语、宿务语、伊洛科语、比科尔语、希利盖农语和瓦莱语。

a）家庭问卷用于列出选定家庭的所有常驻成员和访客。收集的关于每个列出的人的基本信息包括年龄、性别、教育和与户主的关系。家庭问卷的主要目的是确定有资格进行个人访谈的妇女和男性。家庭住房单元的特征信息，如水源、卫生设施类型、房屋地板材料以及各种耐用品的所有权，也记录在家庭问卷中。这些项目是家庭社会经济地位的指标。

b）健康模块旨在使相关机构了解人口的健康状况、实践和态度。该模块包括以下主题：
- 医疗设施利用
- 非传染性疾病
- 传染病
- 传统药物、治疗实践和替代医疗保健方式
- 医疗保健融资 - 环境健康。

c）女性问卷用于收集所有15-49岁女性的信息。这些女性被问及以下主题：
- 背景特征（例如，教育、媒体曝光）
- 生殖史
- 家庭规划方法的认知和使用
- 生育偏好
- 产前、分娩和产后护理
- 母乳喂养和婴儿喂养实践
- 疫苗接种和儿童疾病
- 婚姻和性行为
- 妇女的工作和丈夫的背景特征
- 婴儿和儿童的喂养实践
- 儿童死亡率
- 关于艾滋病的认知和行为以及其他性传播感染
- 关于结核病的认知和行为