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SLDHS（斯利曼尼亚人口与健康调查）收集了关于生育水平、婚姻状况、性行为、生育偏好、计划生育方法的认识和使用、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/HIV和其他性传播感染的认知和行为等信息。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、地区和地区层面的生育、死亡率、计划生育、孕产妇和儿童健康、营养、疟疾和艾滋病/HIV等健康和人口指标数据，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；
• 衡量生育和避孕使用率的变化；
• 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、产前和分娩服务使用情况、近期儿童疾病的治疗、疫苗接种服务使用情况、蚊帐使用和儿童及孕产妇疟疾治疗；
• 描述与艾滋病/HIV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割礼的广泛程度和模式；
• 估计全国、地区和地区层面的艾滋病感染率，以及城市和农村居住情况。

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进一步细分至地区层面。该调查从15-49岁生育年龄妇女的样本以及从15-59岁男性的家庭样本中收集了人口和健康问题信息。

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样本旨在为国家整体、城市和农村地区以及塞拉利昂的四个地区和14个地区提供重要变量的可靠估计。样本首先分层，以提供城市和农村地区以及所有地区和地区的充分代表性。然后，样本分两阶段选择。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枚举区域名单选择一级抽样单位（PSU），也称为聚类。枚举区域为绘制435个聚类（277个农村和158个城市）提供了主框架，这些聚类按其规模的大小以概率比例选择。抽样框架排除了集体住房单位（如酒店、医院、工作营、监狱或寄宿学校）中居住的人口。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岁年龄的女性，只要她们是常驻家庭成员或调查前一夜在所选家庭中过夜，都有资格接受个人访谈。此外，在每两个被选中的家庭样本中，所有15-59岁的男性都被选中进行访谈。在这个子样本中，所有符合个人调查资格的妇女和男性都有资格进行艾滋病测试。此外，在这个家庭样本子样本中，所有符合调查资格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，在这个相同的家庭样本子样本中，所有符合调查资格的妇女和男性以及所有5岁以下的儿童都有资格进行体格测量（身高和体重）以确定其营养状况。

有关详细信息的更多信息，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，但对该模型问卷进行了补充和修改，以适应特定情况和塞拉利昂的词汇。

家庭问卷用于列出所有常驻家庭成员以及前一晚在所选家庭中过夜的非常驻成员。收集了关于列出的每个人特征的某些基本信息，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童工的模块。此外，还包括了几个问题，以确定住宅的物理特征，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个人访谈的资格，即15-49岁的妇女和15-59岁的男性。此外，家庭问卷还用于登记有资格进行体格测量和收集贫血和艾滋病测试血液样本的人员。

妇女问卷用于收集所有生育年龄妇女（15-49岁）的信息。关于家庭暴力的问卷旨在获取妇女的暴力经历信息。这些问题在未选中男性调查的家庭样本中向每个家庭的一名妇女进行。在有多名符合资格的妇女的家庭中，遵循了特殊程序（使用“基什网格”），以确保关于家庭暴力的访谈是随机选择的。

男性问卷用于样本中每两个家庭中的所有15-59岁男性。在每户选中男性问卷的家庭中，随机选择一名男性接受关于家庭暴力的问卷。

数据清理
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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，在那里办公室编辑人员审查了它们，并手动记录了少数没有预先编码答案的问题的代码。数据使用CSPro（人口和调查处理计算机包）进行处理。数据录入和编辑几乎在实地工作开始后立即开始。包括编辑、数据录入、100%双录入、最终编辑和验证在内的数据处理于2013年11月完成。

响应率
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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个被成功访谈，响应率为99%。

在访谈的家庭中，确定了17,132名符合资格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，响应率为97%。在为男性调查选择的子样本家庭中，确定了7,537名符合资格的男性，其中7,262名被成功访谈，响应率为96%。

抽样误差估计
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样本调查的估计受到两种类型误差的影响：非抽样误差和抽样误差。非抽样误差是由于在实施数据收集和处理过程中出现的错误造成的，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年塞拉利昂人口与健康调查（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。

与抽样误差相反，抽样误差可以统计评估。2013年SLDHS中选中的受访者样本只是从同一人口中可能选择出的许多样本之一，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。虽然差异程度不完全可知，但可以从调查结果中估计出来。

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，在此区间内可以合理地假设人口的真实值。

例如，对于从样本调查计算出的任何给定的统计量，该统计量的值将在95%的所有可能样本中，与相同大小和设计的实际样本选定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来计算抽样误差。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。此程序使用泰勒线性化方法进行方差估计，该方法用于均值或比例的估计。对于更复杂的统计量，如生育率和死亡率，使用Jackknife重复复制方法进行方差估计。

关于抽样误差计算的更详细信息，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
- 符合资格和被访谈的妇女年龄分布
- 符合资格和被访谈的男性年龄分布
- 报告的完整性
- 日历年度出生情况
- 死亡年龄报告（按天数）
- 死亡年龄报告（按月份）
- 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
- 兄弟姐妹的家族大小和性别比

注意：这些表格在最终报告的附录C中呈现。