Demographic and Health Survey 1988 - Ghana

Abstract
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The Ghana Demographic and Health Survey (GDHS) is a national sample survey designed to provide information on fertility, family planning and health in Ghana. The survey, which was conducted by the Statistical Service of Ghana, is part of a worldwide programme coordinated by the Institute for Resource Development/Macro Systems, Inc., in more than 40 countries in Africa, Asia and Latin America.

The short-term objectives of the Ghana Demographic and Health Survey (GDHS) are to provide policymakers and those implementing policy with current data on fertility levels, knowledge and use of contraception, reproductive intentions of women 15-49, and health indicators. The information will also serve as the basis for monitoring and evaluating programmes initiated by the government such as the extended programme on immunization, child nutrition, and the family planning programme. The long-term objectives are to enhance the country's ability to undertake surveys of excellent technical quality that seek to measure changes in fertility levels, health status (particularly of children), and the extent of contraceptive knowledge and use. Finally, the results of the survey will form part of an international data base for researchers investigating topics related to the above issues.

Geographic coverage
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National

Analysis unit
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- Household
- Children under five years
- Women age 15-49
- Men

Kind of data
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Sample survey data

Sampling procedure
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The 150 clusters from which a representative sample of women aged 15-49 was selected from a subsample of the 200 clusters used for the Ghana Living Standards Survey (GLSS). All census Enumeration Areas (EAs) were first stratified by ecological zones into 3 strata, namely Coastal Savanna, Forest, and Northern Savanna. These were further stratified into urban, semi-urban, and rural EAs. The EAs (in some cases, segments of EAs) were then selected with probability proportional to the number of households. All households in the selected EAs were subsequently listed.

Note: See detailed description of sample design in APPENDIX B of the survey report.

Mode of data collection
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Face-to-face

Research instrument
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Three different types of questionnaires were used for the GDHS. These were the household, individual and the husband questionnaires. The household and the individual questionnaires were adapted from the Model "B" Questionnaire for the DHS program. The GDHS is one of the few surveys in which special effort was made to collect information from husbands of interviewed women on such topics as fertility preferences, knowledge and use of contraception, and environmental and health related issues.

All usual members and visitors in the selected households were listed on the household questionnaire. Recorded in the household questionnaire were data on the age and sex of all listed persons in addition to information on fostering for children aged 0-14. Eligible women and eligible husbands were also identified in the household questionnaire.

The individual questionnaire was used to collect data on eligible women. Eligible women were definedas those aged 15-49 years who spent the night prior to the household interview in the selected household, irrespective of whether they were usual members of the household or not. Items of information collected in this questionnaire are as follows:
1) Respondent's Background
2) Reproductive Behavior
3) Knowledge and Use of Contraception
4) Health and Breastfeeding
5) Marriage
6) Fertility Preferences
7) Husband's Background and Women's Work
8) Weight and Height of Children Aged 3-36 Months.

In half of the selected clusters a husband's questionnaire was used to collect data on eligible husbands. Eligible husbands were defined as those who were co-resident with their wives and whose wives had been successfully interviewed. Data on the husband's background, contraceptive knowledge and use, as well as fertility preferences were collected.

All three questionnaires were translated into seven local languages, namely, Twi, Fante, Nzema, Ga, Ewe, Hausa and Dagbani. All the GDHS interviewers were able to conduct interviews in English and at least one local language. The questionnaires were pretested from mid-October to early November 1987. Five teams were used for the pretest fieldwork. These included 19 persons who were trained for 11 days.

Cleaning operations
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Completed questionnaires were collected weekly from the regions by the field coordinators. Coding, data entry and machine editing went on concurrently at the Ghana Statistical Service in Accra as the fieldwork progressed. Coding and data entry were started in March 1988 and were completed by the end of June 1988. Preliminary tabulations were produced by mid-July 1988, and by August 1988 preliminary results of the survey were published.

Response rate
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Of the 4966 households selected, 4406 were successfully interviewed. Excluding 9 percent of households that were vacant, absent, etc., the household response rate is 98 percent.

Out of 4574 eligible women in the household schedule, 4488 were interviewed successfully. The response rate at the individual level is 98 percent. Of the 997 eligible husbands, 943 were successfully interviewed, representing a response rate of 95 percent.

Sampling error estimates
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The results from sample surveys are affected by two types of errors: non-sampling error and sampling error. The former is due to mistakes in implementing the field activities, such as failing to locate and interview the correct household, errors in asking questions, data entry errors, etc. While numerous steps were taken to minimize this sort of error in the GDHS, non-sampling errors are impossible to avoid entirely, and are difficult to evaluate statistically.

Sampling errors, on the other hand, can be evaluated statistically. The sample of women selected in the GDHS is only one of many samples of the same size that could have been drawn from the population using the same design. Each sample would have yielded slightly different results from the sample actually selected. The variability observed among all possible samples constitutes sampling error, which can be estimated from survey results (though not measured exactly).

Sampling error is usually measured in terms of the "standard error" (SE) of a particular statistic (mean, percentage, etc.), which is the square root of the variance of the statistic across all possible samples of equal size and design. The standard error can be used to calculate confidence intervals within which one can be reasonably sure the true value of the variable for the whole population falls. For example, for any given statistic calculated from a sample survey, the value of that same statistic as measured in 95 percent of all possible samples of identical size and design will fall within a range of plus or minus two times the standard error of that statistic.

If simple random sampling had been used to select women for the GDHS, it would have been possible to use straightforward formulas for calculating sampling errors. However, the GDHS sample design used three stages and clusters of households, and it was necessary to use more complex formulas. Therefore, the computer package CLUSTERS, developed for the World Fertility Survey, and was used to compute sampling errors.

Note: See detailed estimate of sampling error calculation in APPENDIX C of the survey report.

摘要
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加纳人口与健康调查（GDHS）是一项国家级抽样调查，旨在为加纳提供关于生育、家庭规划和健康方面的信息。该调查由加纳统计局实施，是全球性项目的一部分，由资源发展研究所/宏系统公司协调，在非洲、亚洲和拉丁美洲的40多个国家进行。

加纳人口与健康调查（GDHS）的短期目标是向政策制定者和政策执行者提供关于生育水平、避孕知识的掌握和使用情况、15-49岁女性的生殖意图以及健康指标的最新数据。这些信息还将作为监测和评估政府启动的计划的依据，例如扩大免疫计划、儿童营养和家庭规划计划。长期目标是提高国家开展高技术质量调查的能力，旨在衡量生育水平、健康状况（尤其是儿童健康状况）以及避孕知识的掌握和使用程度的改变。最后，调查结果将成为国际数据库的一部分，供研究上述相关问题的研究人员使用。

地理覆盖范围
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全国

分析单元
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- 家庭
- 5岁以下儿童
- 15-49岁女性
- 男性

数据类型
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样本调查数据

抽样程序
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从用于加纳生活标准调查（GLSS）的200个聚类中选取了150个聚类，从中对15-49岁女性的代表性样本进行了选择。所有人口普查区（EA）首先根据生态区分为3个层次，即沿海萨凡纳、森林和北部萨凡纳。这些区域进一步细分为城市、半城市和农村地区。然后，根据家庭数量按比例选择EA（在某些情况下，选择EA的部分区域）。随后，在选定的EA中列出了所有家庭。

注意：有关样本设计的详细描述，请参阅调查报告附录B。

数据收集方式
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面对面

研究工具
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GDHS使用了三种不同类型的问卷。这些是家庭问卷、个人问卷和配偶问卷。家庭和个人问卷是从DHS项目的模型“B”问卷中改编的。GDHS是少数几个努力收集受访女性配偶关于生育偏好、避孕知识的掌握和使用情况以及环境和健康相关问题的调查之一。

家庭问卷中列出了选定家庭中的所有常规成员和访客。记录在家庭问卷中的数据包括所有列出的个人的年龄和性别，以及0-14岁儿童的抚养信息。家庭问卷中还确定了合格的女性和合格的女性配偶。

个人问卷用于收集合格女性的数据。合格的女性被定义为年龄在15-49岁之间，在家庭访谈前一晚在选定家庭过夜的女性，无论她们是否是家庭的常规成员。该问卷收集的信息如下：
1) 受访者背景
2) 生殖行为
3) 避孕知识的掌握和使用情况
4) 健康和母乳喂养
5) 婚姻
6) 生育偏好
7) 配偶背景和女性工作
8) 3-36个月儿童体重和身高。

在选定的一半聚类中，使用配偶问卷收集合格男性的数据。合格男性是指与妻子共同居住且妻子已成功接受访谈的人。收集了配偶的背景、避孕知识的掌握和使用情况以及生育偏好。

所有三种问卷均翻译成七种地方语言，即蒂维语、芳蒂语、恩泽马语、加语、埃维语、豪萨语和达甘巴尼语。所有GDHS访谈员都能用英语和至少一种地方语言进行访谈。问卷于1987年10月中旬至11月初进行了预测试。使用了五个团队进行预测试工作。这些团队包括19人，他们接受了11天的培训。

数据清理操作
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已完成问卷每周由区域协调员收集。编码、数据录入和机器编辑在加纳统计局阿克拉进行，同时进行现场工作。编码和数据录入始于1988年3月，并于1988年6月底完成。初步汇总于1988年7月中旬产生，并于1988年8月发布了调查的初步结果。

响应率
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在选定的4966户家庭中，4406户成功接受了访谈。排除9%的空置、缺席等家庭后，家庭响应率为98%。

在家庭计划中，4574名合格女性中有4488人成功接受了访谈。个人层面的响应率为98%。在997名合格男性中，943人成功接受了访谈，代表响应率为95%。

抽样误差估计
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样本调查的结果受到两种类型误差的影响：非抽样误差和抽样误差。前者是由于现场活动实施中的错误造成的，例如未能找到和访谈正确的家庭、提问错误、数据录入错误等。虽然GDHS采取了众多措施来最大限度地减少此类错误，但非抽样误差是无法完全避免的，并且难以进行统计分析。

另一方面，抽样误差可以通过统计方法进行评估。GDHS中选定的女性样本只是从人口中抽取的许多相同大小的样本之一，这些样本使用相同的设计从人口中抽取。每个样本都会产生与实际选定的样本略有不同的结果。所有可能样本之间的可变性构成了抽样误差，可以从调查结果中估计（尽管不能精确测量）。

抽样误差通常以特定统计量（均值、百分比等）的“标准误差”（SE）来衡量，它是所有可能样本的方差平方根，这些样本具有相同的大小和设计。标准误差可用于计算置信区间，其中可以合理地确保整个变量的真实值落在该区间内。例如，对于从样本调查中计算出的任何给定统计量，该统计量在所有可能样本中测量的值将在95%的情况下落在该统计量的标准误差的两倍范围内。

如果对GDHS中选定的女性使用简单随机抽样，则可以使用简单的公式来计算抽样误差。然而，GDHS的样本设计使用了三个阶段和家庭聚类，因此需要使用更复杂的公式。因此，用于世界生育调查开发的计算机包CLUSTERS被用于计算抽样误差。

注意：有关抽样误差计算详细估计，请参阅调查报告附录C。