APHRC Online Microdata Library
    Home / Central Data Catalog / POPULATION_DYNAMICS_AND_URBANIZATION_IN_AFRICA / APHRC-NCSS2-2014-V1.0
Population_Dynamics_and_Urbanization_in_Africa

Nairobi Cross-sectional Slums Survey (NCSS), 2012, 2nd Survey

KENYA, 2012
Population Dynamics and Urbanization in Africa (PDAU)
African Population & Health Research Center
Last modified January 05, 2016 Page views 2326377 Documentation in PDF Metadata DDI/XML JSON

Identification

IDNO
APHRC-NCSS2-2014-v1.0
Title
Nairobi Cross-sectional Slums Survey (NCSS), 2012, 2nd Survey
Subtitle
2nd Survey
Translated Title
English
Country
Name Country code
KENYA KEN
Abstract
The overarching goal of NCSS 2012 was to strengthen the evidence base to guide policies and programs aimed at improving the wellbeing of the urban poor. Specifically, the survey pursued three main objectives:

1. To document current population and health challenges among the residents of Nairobi's informal settlements.

2. To take stock of the changes (or the lack thereof) in health outcomes, livelihood conditions and demographic behavior among slum dwellers in Nairobi, ten years after the NCSS 2000.

3. To compare indicators among slum dwellers in Nairobi to other urban population sub-groups and rural dwellers in Kenya.

Version

Version number
APHRC-NCSS2-2012-v1.0
Version Date
2012-11-30
Version Notes
Version 1.0, February 2015, with anonymised datasets and study materials.

Coverage

Geographic Coverage
Informal settlements (slums) in Nairobi county, Kenya.
Unit of Analysis
Individuals, Households
Universe
The survey covered all de jure household members (usual residents), all women aged 12-49 years resident in the household, and men aged 12-54 years resident in every other household.

Producers and sponsors

Authoring entity/Primary investigators
Agency Name Affiliation
African Population & Health Research Center APHRC
Producers
Name Affiliation Role
Blessing Mberu APHRC Investigator
Donatien Beguy APHRC Investigator
Funding Agency/Sponsor
Name Abbreviation Role
Bill and Melinda Gates Foundation Gates Foundation Funder
Other Identifications/Acknowledgments
Name Role
Residents of Nairobi Informal Settlements (Slums) Study Subjects
Community leaders - chiefs and village elders Support to field teams
Kenya National Bureau of Statistics (KNBS) Providing a sampling frame and for offering their expertise in mapping and other field logistics

Sampling

Sampling Procedure
The sample for the NCSS 2012 was designed to allow estimation of key indicators in the slums of Nairobi with a margin of error of 2-5 points (95% level of confidence). The following indicators were considered in the sample size calculation: under-5 mortality rate, percentage of under-5 children who had diarrhea in the 2 weeks preceding the survey, percentage of children aged 12-23 months who have been vaccinated against measles, and percentage of children aged 12-23 months who have been fully immunized.

The number of households required to estimate each indicator was then obtained by adjusting the resulting sample size according to the proportion of the target population to the entire population, non-response rate and average household size. And since the number of households required to estimate the percentage of children 12-23 months who are fully immunized is large enough to allow estimation of the other indicators with the specified precision, we therefore used the proportion of fully immunized children in the poorest wealth quintile (65.9% according to KDHS 2008-09) as an estimate of the proportion of full immunization coverage in Nairobi informal settlements (slums). Using a sampling formula, we estimated that a minimum of 518 children was required to estimate full immunization coverage in the slums. Then by adding to the above formula the proportion of children aged 12-23 months living in the slum (3.52% according NUHDSS, 2006-2010 in Korogocho and Viwandani slums), it was estimated that 14,714 individuals (=518/0.0352) would need to be interviewed to be able to reach 518 children aged 12-23 months. Given an estimated average household size of 2.5 in the NUHDSS slums, 5,886 (=14,714/2.5) households would need to be visited to reach 14,714 individuals. Assuming a 10 percent household non-response rate, an initial 6,540 households (5,886 / (1-0.10)) were sampled.

The distribution of the sample by clusters or Enumeration Areas (EAs) was estimated according to the relative size of each administrative location. The list of administrative locations containing at least one EA categorized as an informal settlement or slum was obtained from the 2009 Kenya Population and Housing Census. A total of 42 administrative locations comprising 3,939 slum EAs were identified. A two-stage sampling methodology was then used to select the 6,540 households.

At the first stage, 30% of the sampled EAs were selected using the probability proportional to population size (PPP) sampling methodology and this yielded 220 EAs (6540/ (100/0.3)) distributed across the 42 administrative locations. A household listing carried out within each cluster found that a total of 188 EAs still existed, four years after the 2009 national census and that 32 EAs were no longer in existence due to demolitions and flooding.

At the second stage, to reduce intra-cluster correlation, a random sample of only 35% of the households in each cluster was drawn based on the household listing and this produced 6,583 households. A total of 314 vacant structures were dropped from the initial number of sampled households, which reduced the sample size to 6,269 households. Of these, 5,490 households were successfully interviewed yielding a household response rate of 88 percent.
Deviations from the Sample Design
None
Response Rate
Households: 6583 sampled, 6269 eligible, 5490 completed, 88% response rate

Women (12-49): 4912 sampled, 4912 eligible, 4240 completed, 86% response rate

Men(12-54): 3137 sampled, 3137 eligible, 2377 completed, 76% response rate

Adolescent Girls (12-24): 1964 sampled, 1964 eligible, 1963 completed, 100% response rate

Adolescent Boys (12-24): 937 sampled, 937 eligible, 807 completed, 86% response rate
Weighting
The data are weighted as follows:

Household datasets: hhd_weight

Women datasets: wom_weight

Men datasets: man_weight

Women+Men datasets: wom_man_weight

Data Collection

Dates of Data Collection (YYYY/MM/DD)
Start date End date
2012-06-01 2012-11-30
Time periods (YYYY/MM/DD)
Start date End date
2012-07-01 2013-01-31
Mode of data collection
Face-to-face [f2f]
Supervision
The main survey data collection exercise was carried out by 8 teams comprising a field supervisor and between 5-7 interviewers.



Field supervisors:

1. Were in charge of the general administration of their teams and served as the link between the project management and the field teams.

2. They also ensured that their teams had all the necessary survey materials and organized for community guides and security when required.

3. They supported in the collection of anthropometric data of under 5 children.

4. They were in charge of quality control through back-checks on 10 percent of completed questionnaires, spot-checks, sit-ins during interviews and editing of all completed questionnaires.



Project management staff also carried out field-visits, conducted spot-checks, verified interviews and discussed areas of concern with field teams.
Type of Research Instrument
Data were collected using both netbooks and paper questionnaires, where it was not possible to use the netbooks. Three questionnaires were administered: a household questionnaire and separate questionnaires for women and men.

The Household Questionnaire collected data on the socio-demographic characteristics of household members and visitors who slept in the house the previous night. The questionnaire included modules on household characteristics, household poverty and wellbeing including food security, transfers and remittances, and under-5 children anthropometric measurements. The questionnaire was administered to the head of the household or any other adult/credible household member. A list of household members was used to identify persons eligible for the individual interviews.

The Women's Questionnaire was administered to females aged 12 to 49 years in the sampled households. This questionnaire had several modules including socio-demographic characteristics, migration history, reproduction, contraception, pregnancy, ante-natal and post-natal care, child immunization and child health, marriage, fertility preferences, husband's background and the woman's work/livelihood activities, HIV/AIDS and other sexually transmitted infections, general health issues and maternal mortality. Women aged 12-24 years completed an additional module that addressed issues relevant to young people's health and wellbeing including unintended pregnancy and abortion and drug and alcohol use.

The Men's Questionnaire was administered to eligible males aged 12 to 54 years in the sampled households. The questionnaire had several modules including socio-demographic characteristics, reproduction, contraception, marriage, fertility preferences, work/livelihood activities and gender roles, HIV/AIDS and other sexually transmitted infections and general health issues. Males aged 12-24 years completed an additional module on issues relevant to young people's health and wellbeing.



NB: All questionnaires and modules are provided as external resources.

Data Processing

Cleaning Operations
Data editing took place at a number of stages throughout the processing, including:

1. Quality control through back-checks on 10 percent of completed questionnaires, spot-checks, sit-ins during interviews and editing of all completed questionnaires by supervisors and project management staff.

2. A research assistant performed internal consistency checks for all questionnaires and edited all paper questionnaires coming from the field before their submission for data entry with return of incorrectly filled questionnaires to the field for error-resolution.

3. During data entry.

4. Data cleaning and editting was carried out using STATA Version 12.1 software.
Other Processing
Data were entered as follows:

1. Using Netbooks.

2. Typed based on paper questionnaires, where it was not possible to use the netbooks.



In both cases, data were captured using in-house software developed with a Visual Basic. Net front-end and a Microsoft Structured Query Language (SQL) Server back-end.

Data access

Contact
Name Affiliation Email
Head Statistics and Surveys Unit APHRC info@aphrc.org
Conditions
All non-APHRC staff seeking to use data generated at the Center must obtain written approval to use the data from the Director of Research. This form is developed to assess applications for data use and facilitate responsible sharing of data with external partners/collaborators/researchers. By entering into this agreement, the undersigned agrees to use these data only for the purpose for which they were obtained and to abide by the conditions outlined below:

1. Data Ownership: The data remain the property of APHRC; any unauthorized reproduction and sharing of the data is strictly prohibited. The user will, therefore, not release nor permit others to use or release the data to any other person without the written authorization from the Center.

2. Purpose: The provided data must be used for the purpose specified in the Data Request Form; any other use not specified in the form must receive additional or separate authorization.

3. Respondent Identifiers: The Center is committed to protecting the identity of the respondents who provide information in its research. All analytical data sets (both qualitative and quantitative) released by the Data Unit MUST are stripped of respondent identifiers to protect the identity of the respondents. By accepting to use APHRC data, the user is pledging that he/she will not, under any circumstance, regenerate the identifiers or permit others to use the data to learn the identity of any individual, household or community included in any data set.

4. Confidentiality pledge: The user will not use nor permit others to use the data to report any information in the data sets that could identify, directly or by inference, individuals or households.

5. Reporting of errors or inconsistencies: The user will promptly notify the Head of the Statistics and Survey Unit any errors discovered in the data as soon as the errors are discovered.

6. Publications resulting from APHRC data: The Center requires external collaborators to work with APHRC staff on all publications resulting from its data. In order to facilitate this, lead authors should send a detailed concept note of the paper (including the background, rationale, data, analytical methods, and preliminary findings) to the Principle Investigator (or Theme Leader) for the project (with a copy to the Director of Research), who will circulate the abstract to concerned researchers for possible expression of interest in participating in the publication as co-authors. Any exception to the involvement of APHRC staff should be approved by the Director of Research, APHRC.

7. Security: The user will take responsibility for the security of the data by ensuring that the data are used and stored in a secure environment where access is password protected. This will ensure that non-authorized people should not have access to the data.

8. Loss of privilege to use data: In the event that APHRC determines that the data user is in violation of the conditions for using the data, or if the user wishes to cancel this agreement, the user will destroy the data files provided to him/her. APHRC retains the right to revoke this agreement or informs publishers to withhold publication of any work based wholly or in part on its data if the conditions for using the data are violated.

9. Acknowledgement: Any work/reports from this data must acknowledge APHRC as the source of these data. For example, the suggested acknowledgement for NUHDSS data is:

“This research uses livelihoods data collected under the longitudinal Nairobi Urban Health and Demographic Surveillance System (NUHDSS) since 2006. The NUHDSS is carried out by the African Population and Health Research Center in two slums settlements (Korogocho and Viwandani) in Nairobi City.”

Additionally all funders, the study communities that provided the data, and staff who collected and analyzed or processed the data should be acknowledged.

10. Deposit of Reports/Papers: The user should submit electronic and paper copies of all publications generated using APHRC data to the Policy Engagement and Communications Department, with copies to the Director of Research.

11. Change of contact details: The user will promptly inform the Director of Research of any change in your personal details as contained on this data request form.
Citation requirement
African Population and Health Research Center, Nairobi Cross-sectional Slums Survey 2012, February 2015.APHRC, Nairobi, Kenya. doi:11239/176-2014-026-1.0

Contacts

Contact
Name Affiliation Email URI
Director of Research African Population & Health Research Center info@aphrc.org www.aphrc.org

Metadata production

Document ID
APHRC-NCSS2-2014-v1.0
Producers
Name Abbreviation Affiliation Role
African Population & Health Research Center APHRC APHRC Metadata Producer
Date of Production
2014-07-01
Document version
Version 1.0