Malaria Indicators Survey 2005 - Liberia

Abstract
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The overall objective of the Liberia Malaria Indicators Survey (LMIS) was to updae the baseline core indicators of malaria in Liberia.

Specific objectives were to:
1. Obtain data on malaria prevention in households (use of ITNs; IPT for Pregnant Women)
2. Obtain data on fever management in HH
3. Obtain data on prevalence of malaria, anemia
4. Explore Knowledge, Attitude, Practice (KAP)
5. Assess the performance of health workers in the management of malaria
6. Establish the proportion of malaria among patients
7. Establish malaria mortality rate among in-patients

The survey was conducted both in the community and in health facilities. Two types of questionnaires were developed.: the household questionaire and the woman's questionnaire. A portable photospectometer to detect anemia and a rapid diagnostic test to detect plasmodium falciparum malaria were used.

Geographic coverage
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National

Analysis unit
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- Household
- Children age 0-5
- Women age 15 to 49
- Health Facilities

Universe
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All the 15 counties were included in the study, hence the entire population of Liberia constituted the study universe.
Health Facilities.

Kind of data
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Sample survey data [ssd]

Sampling procedure
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The last Population and Housing Census for Liberia was conducted in 1984. At that time, a National Sampling Frame comprising of 4,800 EAs was constructed for the Census. Not only is this frame 20 years old, but there has also been many undocumented changes in the size, structure and distribution of population and dwellings. During the 20 years period, many new communities were established, while existing ones had expanded or contracted due to migration and changes in socio-economic development. Additionally, the civil war led to the destruction of many communities and dwellings and massive displacements of the population of certain communities, as well as the death of thousands of people. These new developments have not been documented, what makes the existing sampling frame to be outdated and obsolete to be used in selecting samples for the Liberia Malaria Indicators Survey (LMIS) without undertaking a major verification exercise.
In 1999/2000, the Government of Liberia and its partners conducted a Demographic and Health Survey (DHS) using the 1984 National Sampling Frame to select and verify 600 EAs. Even though these 600 EAs are more than 5 years old now and were affected by recent civil wars, they have been considered a National Sampling Frame for the LMIS, since in fact they were nationally selected, verified and can be easily identified and verified at this point of time, thereby saving cost.

A two-stage (EAs at first stage and households at second stage) stratified sample design was developed for the 2005 LMIS. At the first stage, the 600 EAs were stratified by county and rural-urban residence. There are 15 counties and 2 rural-urban strata. The urban stratum comprised all county capitals/headquarters plus the City of Monrovia and was divided into 2 domains: (1) City of Monrovia and (2) the county capitals/headquarters. The rural stratum included the rest of the country, that is, all areas outside of the City of Monrovia and the county capitals/headquarters.
Hence, a total of 17 sampling strata were identified, that is, the City of Monrovia, all county capitals/headquarters grouped together as one stratum, and the reminder (rural parts) of the 15 counties. In view of the foregoing and based on the availability of funds, a total of 360 EAs (60%) were selected out of the 600 EAs with probability proportional to size, that is, to the number of households/structures in 1999/2000 DHS Sampling Frame.
In addition to identification and updating of EAs, a complete listing of dwellings/households in the EAs was necessary prior to the selection of households. The listing operation consisted of visiting each of the selected clusters, recording on listing forms a description of every structure together with the names of the heads of the households found in the structure, and drawing a location map of the cluster as well as a sketch map of the structures in the cluster. Twenty field workers (4 teams of 8 interviewers, 4 cartographers and 4 supervisors) completed household listing exercises of the 360 EAs in approximately 40 days (February 25-first week in April, 2005). At the end of the exercise a total of 9000 households were statistically selected for the LMIS from a total of 29,198 households

The selection of EAs within each stratum was undertaken through the following steps:

i) Assign measures of size (MoS) to sample EAs based on the 1999/2000 number of households/structures listed. Let the MoS for the ith EA in the hth stratum = Mhi
ii) Cumulate the Mhi values, i.e., = Mh
iii) Compute the sampling interval (I) as given in the formula below:
Where:
ah = assigned number of sample EAs (see column 3, table 1) for the hth strata,

iv) Using a random number table, find a random number, R, between one and I.
v) Compute the sequence of sampling numbers:
R; R+I; R+2I; R+3I; etc.

B. Cluster Selection Probabilities:
The cluster selection probability for the ith cluster in the hth stratum will be given by:
where: fhi = 1st stage selection probability for the ith PSU in the hth stratum

Since the EAs are sub-samples of the LDHS, the actual selection probability for the ith EA will be given by:
Where phi = LDHS selection probability for the ith Cluster in the hth stratum

See more on sampling in the final report.

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

Research instrument
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The LMIS technical committee used existing DHS, WHO & MACRO Survey instruments (manuals, questionnaires, etc references to add) to produce the LMIS survey tools. Two types of structured questionnaires were developed in english: the Household questionnaire and the women's questionnaire.

It comprises 6 sections :
- Section 0 : Introduction and the interviewee's consent
- Section 1: HH information
- Section 2 : Knowledge , Attitude and Practice
- Section 3: Preventive measures
- Section 4: Fever in children under 5 years old
- Section 5: Mortality data

The women's questionnaire was aimed at collecting information on the use of IPT as part of antenatal service during the last pregnancy that ended in a life birth, prevalence of fever/convulsion among children under five years of age and type/promptness of anti-malarial treatment given to these children. Three sections are noted:
- Section 6: Introduction and woman's consent
- Section 7: Malaria and pregnancy
- Section 8: Fever in children under five years old

Cleaning operations
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The entire filled out questionnaire forms were collected and centralized atthe National Malaria Control Programme in Monrovia. The cleaning process consisted of verifying that sampled HH were visited, that all forms were fully and correctly filled out and that responses were relevant to questions. A control of coherance of variables within a section and between different sections of the questionaires was performed.

Response rate
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Population type Targeted Actual Achieved
Household 9,000 8,226
Overall Sample size All members of sampled HH 40,757
Women (15-49) All wom. aged 15-49 in sampled HH 9,181
Pregnant women All Preg. women in sampled HH 755
Children <5 All children <5 in sampled HH 8,933

On 9,000 targeted HH only 8,226 representing 91, 4 % were reached.

摘要
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利比里亚疟疾指标调查（LMIS）的整体目标是为利比里亚疟疾的基线核心指标进行更新。

具体目标包括：
1. 获取关于家庭疟疾预防的数据（使用蚊帐；孕妇的预防性治疗）
2. 获取家庭中发热管理的数据
3. 获取疟疾和贫血的患病率数据
4. 探索知识、态度和习惯（KAP）
5. 评估卫生工作者在疟疾管理中的表现
6. 确定患者中疟疾的比例
7. 确定住院患者的疟疾死亡率

调查在社区和医疗设施中进行。开发了两种类型的问卷：家庭问卷和妇女问卷。使用便携式分光光度计检测贫血和快速诊断测试检测恶性疟原虫疟疾。

地理覆盖范围
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全国

分析单元
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- 家庭
- 0-5岁儿童
- 15-49岁妇女
- 医疗设施

总体
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研究包括所有15个县，因此利比里亚的整个人口构成了研究总体。医疗设施。

数据类型
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样本调查数据 [ssd]

抽样程序
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利比里亚最后一次人口和住房普查是在1984年进行的。当时，为普查构建了一个包含4,800个选举单位的国家级抽样框架。这个框架不仅已经20年之久，而且人口和居住规模、结构和分布也发生了许多未经记录的变化。在20年的时间里，许多新的社区建立起来，而现有的社区由于移民和社会经济发展的变化而扩张或收缩。此外，内战导致许多社区和住宅被破坏，某些社区的居民大规模流离失所，以及数千人死亡。这些新变化尚未得到记录，使得现有的抽样框架变得过时，无法在没有进行重大验证的情况下用于利比里亚疟疾指标调查（LMIS）的样本选择。

1999/2000年，利比里亚政府和其合作伙伴使用1984年的国家级抽样框架进行了一次人口和健康调查（DHS），以选择和验证600个选举单位。尽管这些600个选举单位现在已经超过5年，并受到近期内战的影响，但它们被考虑为LMIS的国家级抽样框架，因为实际上它们是全国选择的、经过验证的，并且目前可以轻松识别和验证，从而节省了成本。

2005年LMIS开发了一种两阶段（第一阶段为选举单位，第二阶段为家庭）分层抽样设计。在第一阶段，600个选举单位按县和城乡居住地进行了分层。共有15个县和2个城乡分层。城市层包括所有县首府/总部以及蒙罗维亚市，并分为两个领域：（1）蒙罗维亚市和（2）县首府/总部。农村层包括该国其余地区，即蒙罗维亚市和县首府/总部以外的所有地区。因此，总共确定了17个抽样层，即蒙罗维亚市、所有县首府/总部作为一个层，以及剩余的15个县的农村部分。鉴于上述情况，根据资金的可用性，从600个选举单位中选出了360个选举单位（60%），其抽样概率与大小成比例，即与1999/2000年DHS抽样框架中家庭/结构数量成比例。
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