Indoor Residual Spraying (IRS) Impact Evaluation Survey 2009 - Eritrea

Geographic coverage
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The sample covers 150 villages in the Gash Barka region that were randomly assigned to treatement and control groups.

Analysis unit
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Household, Individual

Universe
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The survey covered all household members (usual residents).

Kind of data
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Sample survey data [ssd]

Sampling procedure
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Sampling design
A two-stage cluster design will be used to generate a probability sample of households within the study area for each of the survey domains (control versus intervention groups). Detailed sampling frames consisting of a count of all households within primary sampling unit (PSU - village) are currently available from the NMCP. PSUs will consist of villages within the study area of Gash Barka, divided into intervention and control villages. To maximize sampling efficiency, 58 PSUs will be selected for each survey domain at the first stage, with 15 households selected from each PSU at the second stage, thereby obtaining a total sample size of 1,740 houses (after adding non-response, the total number of houses is equal to 1,914). The list of eligible PSUs for the study was provided by the NMCP. All households within each selected PSU will be enumerated by the Orotta School of Medicine to create the second stage sampling frames for households. Enumeration of households within each PSU will also allow data to be weighted during analysis if needed. For the second stage, 17 households (ultimate sampling units) will be systematically (systematic random sampling) selected within each enumerated PSU. Data will then be collected at the household level. Survey fieldwork will be conducted just following/during the rainy season in September, 2009.

Sample Size and Power Calculations
A sample size of 870 households in the treatment group (58 villages, 15 households per village) and the same number in the control group will allow the detection (at a 5% level of significance) of a reduction of 10.47% points in malaria parasite prevalence from a baseline of about 15-20% with 80% power. This assumes that the intra-cluster correlation is 0.2. The total sample size is 1,740 households. Adding 10% to account for non-response yields a total sample size of 1,914 houses. Given that there are approximately 4.5 individuals per household, the total sample of individuals will be 8,613.

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

Research instrument
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A household questionnaire for the IRS Impact Evaluation Survey was administered in each household, which collected various information on household members including sex, age, relationship, marital status, health condition, education level and employment status. The household questionnaire includes housing, mosquito avoidance practices, malaria knowledge, fever and cosumption.

The questionnaire is provided as external resources.

地理覆盖范围
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本样本涵盖加什巴卡地区150个村庄，这些村庄被随机分配到治疗组和对照组。
分析单元
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家庭，个人
总体
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调查涵盖了所有家庭成员（常住居民）。
数据类型
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样本调查数据 [ssd]
抽样程序
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抽样设计
将采用两阶段聚类设计，以生成每个调查领域（对照组与干预组）研究区域内家庭的概率样本。目前，从国家疟疾控制项目（NMCP）可获得详细抽样框架，其中包含所有初级抽样单位（PSU - 村庄）内家庭的数量。PSU将由加什巴卡研究区域内的村庄组成，分为干预村和对照组村庄。为了最大化抽样效率，每个调查领域在第一阶段将选择58个PSU，第二阶段从每个PSU中选择15户家庭，从而获得总计1,740户家庭的样本量（考虑非响应后，总户数为1,914户）。NMCP提供了研究适用的PSU清单。奥罗塔医学院将对每个选定的PSU内的所有家庭进行编制，以创建第二阶段的家庭抽样框架。每个PSU内家庭的编制还将允许在分析中根据需要加权数据。在第二阶段，将在每个编制的PSU内系统性地（系统随机抽样）选择17户家庭（最终抽样单位）。数据将在家庭层面收集。调查现场工作于2009年9月雨季期间进行。
样本量和效力计算
在治疗组（58个村庄，每村15户）和控制组中各有870户家庭的样本量将允许检测（在5%的显著性水平下）从约15-20%的基线疟原虫感染率减少10.47个百分点，效力为80%。这假设簇内相关系数为0.2。总样本量为1,740户。增加10%以应对非响应，总样本量为1,914户。鉴于每户约有4.5人，总个体样本量为8,613。
数据收集方式
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面对面 [f2f]
研究工具
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在每个家庭中实施了用于IRS影响评估调查的家庭问卷，该问卷收集了关于家庭成员的各种信息，包括性别、年龄、关系、婚姻状况、健康状况、教育水平和就业状况。家庭问卷包括住房、蚊虫预防措施、疟疾知识、发热和消费情况。
问卷作为外部资源提供。