Survey ID Number
Demographic and Health Survey 2001-2002
The 2001-2002 Zambia Demographic and Health Survey (ZDHS) is a comprehensive nationally representative population and health survey carried out by the Central Statistical Office in partnership with the Central Board of Health. ORC Macro provided financial and technical assistance for the survey through the USAID-funded MEASURE DHS+ programme. Additional funding for the ZDHS was received from the Government of Japan, UNFPA, and DANIDA. The principal objective of the ZDHS is to provide current and reliable data on fertility and family planning behaviour, child mortality, children's nutritional status, the utilization of maternal, child health services, knowledge and prevalence of HIV and syphilis.
The Zambia DHS collected demographic and health information from a nationally representative sample of women and men age 15-49 and 15-59, respectively. The primary focus of the 2001 Zambia DHS is to provide estimates of key population and health indicators, including fertility and mortality rates, for the country as a whole, and for urban and rural areas separately. Also, the sample was designed to provide estimates of key variables for the nine provinces, namely, 1) Central, 2) Copperbelt, 3) Eastern, 4) Luapula, 5) Lusaka, 6) Northern, 7) North-Western, 8) Southern, and 9) Western. In addition, the sample provides basic information for a total of 12 combined districts (not each separately) that are the special focus of the Zambia Integrated Health Programme (Livingstone, Kalomo, Chibombo, Kabwe Urban, Ndola Urban, Kitwe, Chipata, Lundazi, Chama, Kasama, Samfya, and Mwense).
Zambia is divided into nine provinces. In turn, each province is subdivided in districts, each district into constituencies, and each constituency into wards. In addition to these administrative units, during the 2000 population census, each ward was subdivided into convenient areas called census supervisory areas (CSAs), and in turn each CSA into standard enumeration areas (SEAs). In total Zambia has 72 districts, 150 constituencies, 1,289 wards, about 4,400 CSAs, and about 16,400 SEAs. Preliminary information on the counts of households and population, as well as cartographic materials were available from the 2000 population census for the SEAs. Therefore, the sample frame for this survey was the list of SEAs developed from the 2000 population census.
In the preliminary census frame, the SEAs were grouped by CSAs, by CSAs within a ward, by wards within a constituency, by constituencies within a district and by districts within a province for purposes of the ZDHS. The SEAs were further stratified separately by urban and rural areas within each province.
The primary sampling unit (PSU), the cluster for the 2001-2002 ZDHS, is defined on the basis of SEAs from the census frame. A minimum requirement of 85 households for the cluster size was imposed in the design. If an SEA did not have 85 households, it was combined with an adjacent SEA; thus, the ZDHS cluster comprised one or more SEAs. The number of clusters in each district was not allocated proportional to the total population due to the need to present estimates by each of the nine provinces. Zambia is a country where two-thirds of the population reside in rural areas, and one-third in urban areas.
The target for the 2001-2002 ZDHS sample was 8,000 completed interviews. Based on the level of non-response found in the 1996 ZDHS, to achieve this target, approximately 8,200 households were selected, with all women age 15-49 being interviewed. The target was to reach a minimum of 750 completed interviews per province. In each province the number of households was distributed proportionately among the urban and rural areas. Table A.2 shows the distribution of about 8,200 households by province.
The urban-rural distribution was also considered in distributing the sample. The selected households were distributed in 320 clusters in Zambia, 100 clusters in the urban areas, and 220 clusters in the rural areas.
Under this final allocation, the 12 combined districts of the Zambia Integrated Health Programme have 77 selected clusters, 36 in urban areas and 41 in rural areas.
The 2001-2002 ZDHS sample was selected using a stratified two-stage cluster design consisting of 320 clusters, 100 in urban and 220 in rural areas. Once the number of households was allocated to each combination of province by urban and rural areas, the number of clusters was calculated based on an average sample take of 25 completed interviews among women 15-49 years. In each urban or rural area in a given province, clusters were selected systematically with probability proportional to the number of households in each cluster.
Data Collection Notes
The ZDHS involved a number of activities to address various methodological and ethical concerns raised by the inclusion of HIV and syphilis testing as well as to pilot the ZDHS questionnaires. A total of three formal pretests were conducted during this phase of the survey. The training and fieldwork for the first pretest took place May 14-25, 2001. In addition to pretesting the survey questionnaires, the pretest included syphilis and HIV testing using a simple finger prick procedure from which blood spots were collected on filter paper. Four medical laboratory technicians, nine female interviewers, seven male interviewers, and six nurse counselors, were trained, forming seven teams, one for each local language. The pretest fieldwork was conducted in four areas, three urban and one rural. In total, 65 household questionnaires, 79 women's questionnaires and 106 men's questionnaires were completed in the course of three days. A total of 81 persons were identified as eligible for the blood collection. Of these, 52 persons voluntarily agreed to give a sample of blood.
After the first pretest was completed, it was decided that venous rather than capillary blood samples should be collected to be consistent with existing syphilis testing protocols in Zambia. To pilot all of the testing procedures, a second pretest was carried out July 18-24, 2001. Four medical laboratory technicians, five female interviewers and five male interviewers took part in the second pretest. The staff was selected from those individuals who had participated in the first pretest. In the second pretest, 130 questionnaires (38 household, 57 women's and 35 men's questionnaires) were administered. Sixty-nine persons were selected for the venous blood collection. Out of these, 67 (32 males and 35 females) agreed to have their blood tested. In the second pretest, RPR was used as the screening test for syphilis and Abbot Determine test strip as the confirmatory test. The pretest included follow-up treatment or referral for those who tested positive for syphilis. The laboratory technicians also tested the procedures for obtaining dried blood spots from the venous blood samples for later HIV testing.
Using the same staff who took part in the second pretest, a third pretest of the HIV/syphilis protocol was conducted July 26 though August 1, 2001. This pretest focused mainly on gaining additional experience with the informed consent statement in a variety of settings. Five areas were covered, three high-density areas (low income earners areas) and two low-density areas (high income earners areas). In the third pretest, 98 households and 286 individuals were covered. More than 85 percent of respondents agreed to HIV and syphilis testing.
In addition to the three pretests, an additional field exercise was conducted as part of the ZDHS to validate the use of dried blood spots for the HIV testing. In this study, matched DBS and plasma samples were collected and tested. The results of the testing of the matched DBS and plasma samples were similar, leading to the decision to collect DBS samples.
A total of 88 interviewers and 36 nurse/nurse counselors and laboratory technicians participated in the main survey training that took place August 20 through September 16, 2001. All participants were trained in interviewing techniques and the contents of the ZDHS questionnaires. The training was conducted following the standard DHS training procedures, including class presentations, mock interviews, and tests using the Women's Questionnaire. Special training was given to interviewers on the collection of the domestic violence data, especially on issues relating to informed consent and privacy. Male participants were additionally trained on the content of the men's questionnaire. The nurse/nurse counselors were trained to use the scales and height boards to collect anthropometric measurements of women and young children. All of the interviewers were trained in taking height and weight measurements so that they could assist the nurse/nurse counselors in performing these tasks.
During the last week of the training, the nurse/nurse counselors and laboratory technicians, who already had experience in blood collection and testing, were separated and trained on the specific procedures for drawing blood samples in the field and on syphilis testing using RPR. Additionally, they received training specifically focused on the internationally accepted procedures to minimise risk (“universal precautions”) and confidentiality. Finally, in addition to the classroom instruction, the ZDHS training included practice interviews using the questionnaire in English and the participants' local languages.
Data collection for the 2001-2002 ZDHS took place over a seven-month period from November 2001 to May 2002. Twelve interviewing teams carried out data collection. Each team consisted of one team supervisor, one field editor, three to four female interviewers, one male interviewer, one nurse/nurse counselor, one lab technician, and one driver. Six staff assigned from the CSO coordinated and supervised fieldwork activities. They were assisted by staff from the TDRC and the University of Zambia Demography Division. ORC Macro participated in field supervision for interviews, height and weight measurements, and blood collection and testing.
SYPHILISSYPHILIS AND HIV TESTING
In households selected for the male survey, the ZDHS involved the collection of blood specimens from all eligible women and men who voluntarily consented to the syphilis and HIV testing. The initial protocol for the blood specimen collection and testing as well as modifications made in the protocol during the course of the study were reviewed and approved by both the Institutional Review Board of ORC Macro and the Ethical Review Committee of the University of Zambia which approves research studies on human subjects conducted in Zambia.
A total of 3,961 samples were collected in the ZDHS, of which 710 tested positive using the GACELISA. When these positive samples were retested using BIONOR, 570 tested positive and 140 tested negative. Western Blot was then performed for the 140 samples for which the results were discordant, i.e., the GACELISA result was positive and the BIONOR result was negative. Only one of the samples was confirmed as positive and 139 were confirmed as negative with Western Blot.