Demographic and Health Survey 2013 - Sierra Leone

Abstract
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The 2013 SLDHS collected information on fertility levels; marriage; sexual activity; fertility preferences; awareness and use of family planning methods; breastfeeding practices; nutritional status of women and young children; childhood and maternal mortality; maternal and child health; and awareness and behaviour regarding HIV/AIDS and other STIs. The 2013 SLDHS is the first survey to collect data on domestic violence.

The specific objectives of the 2013 SLDHS were to:
• Provide reliable data, at the national, regional, and district levels, on health and demographic indicators in the areas of fertility, mortality, family planning, maternal and child health, nutrition, malaria, and HIV/AIDS, which can be used by programme managers and policy makers to evaluate and improve existing programmes or develop new ones;
• Measure changes in fertility and contraceptive prevalence;
• Examine the basic indicators of maternal and child health in Sierra Leone, including nutritional status, use of antenatal and maternity services, treatment of recent episodes of childhood illness, use of immunisation services, use of mosquito nets and treatment of children and pregnant women for malaria;
• Describe the patterns of knowledge, attitudes, and behaviour related to the transmission of HIV/AIDS and other STIs;
• Ascertain the extent and pattern of domestic violence and female genital cutting in the country;
• Estimate the prevalence of HIV infection at the national, regional and district levels and by urban-rural residence.

The 2013 SLDHS provides data to assist policymakers and programme implementers as they monitor and evaluate existing programmes and design new strategies for demographic, social, and health policies in Sierra Leone.

As in 2008, the 2013 SLDHS survey was designed to cover the entire country. However, unlike the 2008 survey, where disaggregation of data was limited to regional levels, the 2013 SLDHS went further to disaggregate data at the district level. The survey collected information on demographic and health issues from a sample of women of reproductive age 15-49, and also from a sample of men age 15-59 in a subsample of households.

Geographic coverage
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National coverage

Analysis unit
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- Household
- Individual
- Children aged 0-5
- Children aged 5-14
- Women aged 15 to 49
- Men aged 15 to 59

Kind of data
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Sample survey data [ssd]

Sampling procedure
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The 2013 SLDHS sample was designed to produce reliable estimates for important variables for the country as a whole, for urban and rural areas, and for each of Sierra Leone's four regions and 14 districts. The sample was first stratified to provide adequate representation of urban and rural areas, as well as all regions and districts. Then, the sample was selected in two stages. The first stage involved selecting primary sampling units (PSUs), also called clusters, based on the list of enumeration areas (EAs) created in the 2004 Sierra Leone General Population and Housing Census. The enumeration areas provided the master frame for drawing 435 clusters (277 rural and 158 urban), selected with a probability proportional to their size. The sampling frame excluded the population living in collective housing units, such as hotels, hospitals, work camps, prisons, or boarding schools. In the second stage of selection, 30 households were systematically selected from each cluster.

All women age 15-49 who were usual household members or who spent the night before the survey in the selected households were eligible for individual interviews. In addition, in a subsample of every second household selected for the survey, all men age 15-59 were selected for interview. In this subsample, all women and men eligible for the individual survey were also eligible for the HIV test. In addition, in this subsample of households, all women and men eligible for the survey and all children age 6-59 months were eligible for the anaemia test. Finally, in the same subsample of households, all women and men eligible for the survey and all children under the age 5 were eligible for anthropometric (height and weight) measurements to determine their nutritional status.

See Appendix A in the final report for details

Mode of data collection
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Face-to-face [f2f]

Research instrument
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The 2013 SLDHS used three questionnaires, namely, a Household Questionnaire, a Woman’s Questionnaire, and a Man’s Questionnaire. These questionnaires were based on the models developed by the MEASURE DHS Program, but additions and modifications were made to the model questionnaires to adapt them to specific situations and the lexicon of Sierra Leone.

The Household Questionnaire was used to list all usual household members, as well as non-members who spent the night preceding the interview in the selected households. Some basic information was collected on the characteristics of each person listed, including age, sex, education, and relationship to the head of household. The Household Questionnaire also included a module on child labour. In addition, several questions were included to determine the physical characteristics of the dwelling, such as source of water, presence of sanitation facilities, and availability of durable goods. The Household Questionnaire was also used to identify people eligible for the individual interview, that is, women age 15-49 and men age 15-59. In addition, the Household Questionnaire was used to register people eligible for anthropometric measurements and the collection of blood samples for anaemia and HIV testing.

The Woman’s Questionnaire was used to collect information from all women of reproductive age (15-49). The set of questions on domestic violence sought to obtain information on women’s experience of violence. The questions were administered to one woman per household in the subsample households that were not selected for the men’s survey. In households with more eligible women, special procedures (use of a ‘Kish grid’) were followed to ensure that the woman interviewed about domestic violence was randomly selected.

The Man’s Questionnaire was administered to all men age 15-59 living in every second household in the sample. In every household selected for the Man’s Questionnaire, one man was randomly selected to be administered the set of questions on domestic violence.

Cleaning operations
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All questionnaires for 2013 SLDHS were sent to the SSL central office in Freetown, where office editors reviewed them and manually recorded the codes to the few questions without pre-coded answers. The data were processed using CSPro (Census and Survey Processing computer package). Data entry and editing were initiated almost immediately after the beginning of fieldwork. Data processing, consisting of editing, data entry, 100 percent double entry, final editing, and verification, was completed in November 2013.

Response rate
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A total of 13,006 households were selected for the sample, of which 12,724 were occupied. Of the occupied households, 12,629 were successfully interviewed, yielding a response rate of 99 percent.

In the interviewed households, 17,132 eligible women were identified for individual interview; of these, complete interviews were conducted with 16,658 women, yielding a response rate of 97 percent. In the subsample of households selected for the men’s survey, 7,537 eligible men were identified and 7,262 were successfully interviewed, yielding a response rate of 96 percent.

Sampling error estimates
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The estimates from a sample survey are affected by two types of errors: nonsampling errors and sampling errors. Nonsampling errors are the result 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 2013 Sierra Leone Demographic and Health Survey (SLDHS) to minimize this type of error, nonsampling errors are impossible to avoid and difficult to evaluate statistically.

Sampling errors, in contrast, can be evaluated statistically. The sample of respondents selected in the 2013 SLDHS 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 (mean, percentage, etc.), 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 formulae for calculating sampling errors. However, the 2013 SLDHS sample is the result of a multi-stage stratified design, and, consequently, it was necessary to use more complex formulae. The computer software used to calculate sampling errors for the 2013 SLDHS is a SAS procedure. This procedure 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 Taylor linearization method treats any percentage or average as a ratio estimate, r = y/x, where y represents the total sample value for variable y, and x represents the total number of cases in the group or subgroup under consideration.

Further details on sampling errors calculation are given in Appendix B of the final report.

Data appraisal
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Tables were produced to review the quality of the data:
- Household age distribution
- Age distribution of eligible and interviewed women
- Age distribution of eligible and interviewed men
- Completeness of reporting
- Births by calendar years
- Reporting of age at death in days
- Reporting of age at death in months
- Nutritional status of children based on the NCHS/CDC/WHO International Reference Population
- Completeness of information for dead sisters
- Sibship size and sex ratio of siblings

Note: The tables are presented in APPENDIX C of the final report.

摘要
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2013年斯里兰卡人口与卫生调查（SLDHS）收集了关于生育水平、婚姻状况、性行为、生育偏好、计划生育方法的知晓和使用情况、母乳喂养实践、妇女和婴幼儿的营养状况、儿童和孕产妇死亡率、孕产妇和儿童健康、以及关于艾滋病和其他性传播感染（STIs）的知晓和行为等信息。2013年SLDHS是首次收集家庭暴力相关数据的调查。

2013年SLDHS的具体目标包括：
• 提供可靠的国家、地区和地区级别的健康和人口统计指标数据，包括生育、死亡率、计划生育、孕产妇和儿童健康、营养、疟疾和艾滋病，这些数据可供项目管理人员和政策制定者评估和改进现有项目或开发新项目使用；
• 测量生育和避孕普及率的变化；
• 检查塞拉利昂孕产妇和儿童健康的基本指标，包括营养状况、产前和孕产妇服务的使用、近期儿童疾病的处理、免疫接种服务的使用、蚊帐的使用以及儿童和孕产妇的疟疾治疗；
• 描述与艾滋病和其他性传播感染传播相关的知识、态度和行为模式；
• 确定国内暴力和女性生殖器切割的广度和模式；
• 估计国家、地区和地区级别的艾滋病感染率，以及城市和农村居民的感染率。

2013年SLDHS提供数据以协助政策制定者和项目实施者监控和评估现有项目，并设计塞拉利昂人口、社会和健康政策的新的战略。

与2008年类似，2013年SLDHS调查旨在覆盖整个国家。然而，与2008年调查不同，2008年调查的数据细分仅限于地区层面，而2013年SLDHS进一步细分到地区层面。该调查从15-49岁生育年龄妇女的样本中收集了人口和健康问题信息，并从15-59岁男性的样本家庭中收集了信息。

地理覆盖范围
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全国覆盖

分析单元
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- 家庭
- 个人
- 0-5岁儿童
- 5-14岁儿童
- 15至49岁妇女
- 15至59岁男性

数据类型
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样本调查数据 [ssd]

抽样程序
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2013年SLDHS样本旨在为整个国家、城市和农村地区以及塞拉利昂的四个地区和14个地区的重要变量产生可靠估计。样本首先分层，以确保城市和农村地区、所有地区和地区的充分代表性。然后，样本在两个阶段进行选择。第一阶段涉及根据2004年塞拉利昂人口和住房普查中创建的列表选择一级抽样单位（PSU），也称为聚类。枚举区域提供了绘制435个聚类（277个农村和158个城市）的主框架，按其规模的比例选择。抽样框架排除了居住在集体住房单位的人口，例如酒店、医院、工作营、监狱或寄宿学校。在选择的第二阶段，从每个聚类中系统地选择了30个家庭。

所有15-49岁且为常规家庭成员或在前一天晚上在所选家庭过夜的妇女都有资格进行个人访谈。此外，在每两个被选中的家庭中，所有15-59岁的男性都被选进行访谈。在这个子样本中，所有符合条件的妇女和男性都有资格进行HIV测试。此外，在这个子样本家庭中，所有符合条件的妇女和男性以及所有6-59个月大的儿童都有资格进行贫血测试。最后，在同一个子样本家庭中，所有符合条件的妇女和男性以及所有5岁以下的儿童都有资格进行人体测量（身高和体重）测量，以确定其营养状况。

有关详细情况，请参阅最终报告的附录A。

数据收集方式
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面对面 [f2f]

研究工具
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2013年SLDHS使用了三个问卷，即家庭问卷、妇女问卷和男性问卷。这些问卷基于MEASURE DHS项目开发的模型，但对其进行了补充和修改，以适应特定情况和塞拉利昂的词汇表。

家庭问卷用于列出所有常规家庭成员以及在前一天晚上在所选家庭过夜的非成员。收集了有关每个列出的人的特征的基本信息，包括年龄、性别、教育和与户主的关系。家庭问卷还包括一个关于儿童劳动的模块。此外，还包含了一些问题，以确定住宅的物理特征，例如水源、卫生设施的存在和耐用品的可用性。家庭问卷还用于确定符合个人访谈资格的人员，即15-49岁的妇女和15-59岁的男性。此外，家庭问卷用于注册符合人体测量和收集贫血和HIV测试血液样本资格的人员。

妇女问卷用于收集所有生育年龄妇女（15-49岁）的信息。关于家庭暴力的调查问题旨在获取妇女遭受暴力的信息。这些问题在未选为男性调查的子样本家庭中的一户妇女中进行。在有多名符合条件的妇女的家庭中，遵循了特殊程序（使用“基什网格”），以确保被访谈关于家庭暴力的妇女是随机选择的。

男性问卷对样本中每两个家庭中的所有15-59岁男性进行。在每户被选为男性问卷的家庭中，随机选择一名男性接受关于家庭暴力的调查问题。

清理操作
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所有2013年SLDHS问卷都发送到弗里敦的SSL中央办公室，在那里办公室编辑审查了它们，并手动记录了少数没有预先编码答案的问题的代码。使用CSPro（人口普查和调查处理计算机包）处理数据。数据录入和编辑在实地工作开始后几乎立即开始。包括编辑、数据录入、100%双重录入、最终编辑和验证在内的数据处理在2013年11月完成。

应答率
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共选择了13,006个家庭作为样本，其中12,724个被占用。在这些被占用的家庭中，12,629个家庭被成功访谈，应答率为99%。

在访谈的家庭中，确定了17,132名符合条件的妇女进行个人访谈；其中，对16,658名妇女进行了完整的访谈，应答率为97%。在为男性调查选择的子样本家庭中，确定了7,537名符合条件的男性，其中7,262名被成功访谈，应答率为96%。

抽样误差估计
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样本调查的估计受两种类型误差的影响：非抽样误差和抽样误差。非抽样误差是数据收集和处理过程中所犯错误的结果，例如未能找到和访谈正确的家庭、访谈员或受访者对问题的误解以及数据录入错误。尽管在实施2013年塞拉利昂人口与卫生调查（SLDHS）期间采取了众多努力以最大限度地减少此类错误，但非抽样误差不可避免且难以进行统计评估。

相反，抽样误差可以评估。2013年SLDHS中选定的受访者样本只是从同一人口中可能选出的许多样本之一，使用相同的设计和预期规模。这些样本中的每一个都会产生与实际选定的样本结果略有不同的结果。抽样误差是衡量所有可能样本之间差异的指标。尽管变异性程度无法确切知晓，但可以从调查结果中估计。

抽样误差通常以特定统计量（均值、百分比等）的标准误差来衡量，它是方差的平方根。标准误差可用于计算置信区间，其中可以合理假设真实值落在其中。例如，对于从样本调查中计算出的任何给定统计量，该统计量的值将在95%的所有可能样本中落在该统计量的标准误差的两倍范围内。

如果受访者样本被选为简单随机样本，则可以使用简单的公式计算抽样误差。然而，2013年SLDHS样本是分层多阶段设计的产物，因此有必要使用更复杂的公式。用于计算2013年SLDHS抽样误差的计算机软件是SAS程序。该程序使用泰勒线性化方法估计调查估计的方差，该方法适用于均值或比例。使用Jackknife重复复制方法对更复杂的统计量，如生育率和死亡率进行方差估计。

关于抽样误差计算的进一步详细信息，请参阅最终报告的附录B。

数据评估
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制作了表格以审查数据的质量：
- 家庭年龄分布
- 符合条件和被访谈的妇女的年龄分布
- 符合条件和被访谈的男性的年龄分布
- 报告的完整性
- 日历年度出生
- 死亡年龄以天为单位报告
- 死亡年龄以月为单位报告
- 基于NCHS/CDC/WHO国际参考人群的儿童营养状况
- 已故姐妹信息的完整性
- 兄弟姐妹的家族规模和性别比

注意：表格在最终报告的附录C中呈现。