Survey ID Number
IND_2004_NSS60-SCH25_v01_M
Title
National Sample Survey 2004 (60th Round) - Schedule 25 - Morbidity and Healthcare
Sampling Procedure
Sample Design
Outline of sample design
A stratified multi-stage design has been adopted for the 60th round survey. The first stage units (FSU) will be the 1991 census villages in the rural sector and Urban Frame Survey (UFS) blocks in the urban sector. The ultimate stage units (USU) will be households in both the sectors. In case of large villages/blocks requiring hamlet-group (hg)/sub-block (sb) formation, one intermediate stage will be the selection of two hgs/sbs from each FSU.
Sampling Frame for First Stage Units
For the rural sector, the list of Census 1991 villages (panchayat wards for Kerala) and Census 1981 villages for J & K will constitute the sampling frame. For the urban sector, the list of latest available Urban Frame Survey (UFS) blocks will be considered as the sampling frame.
Stratification
Rural sector: Two special strata will be formed at the State/ UT level, viz.
Stratum 1: all FSUs with population between 0 to 50 and
Stratum 2: FSUs with population more than 15,000.
Special stratum 1 will be formed if at least 50 such FSUs are found in a State/UT. Similarly, special stratum 2 will be formed if at least 4 such FSUs are found in a State/UT. Otherwise, such FSUs will be merged with the general strata.
From FSUs other than those covered under special strata 1 and 2, general strata will be formed and its numbering will start from 3. Each district of a State/UT will normally be treated as a separate stratum. However, if the census rural population of the district is greater than or equal to 2.5 million as per population census 2001 or 2 million as per population census 1991, the district will be split into two or more strata, by grouping contiguous tehsils to form strata. However, in Gujarat, some districts are not wholly included in an NSS region. In such cases, the part of the district falling in an NSS region will constitute a separate stratum.
Urban sector: In the urban sector, strata will be formed within each NSS region on the basis of size class of towns as per Population Census 2001. The stratum numbers and their composition (within each region) are given below.
stratum 1 : all towns with population less than 50,000
stratum 2 : all towns with population 50,000 or more but less than 2 lakhs
stratum 3 : all towns with population 2 lakhs or more but less than 10 lakhs
stratum 4, 5, 6,...: each town with population 10 lakhs or more
The stratum numbers will remain as above even if, in some regions, some of the strata are not formed.
Total sample size (FSUs)
7612 FSUs have been allocated at all-India level on the basis of investigator strength in different States/UTs for central sample and 8260 for state sample.
Allocation of total sample to States and UTs
The total number of sample FSUs is allocated to the States and UTs in proportion to provisional population as per Census 2001 subject to the availability of investigators ensuring more or less uniform work-load.
Allocation of State/UT level sample to rural and urban sectors
State/UT level sample is allocated between two sectors in proportion to provisional population as per Census 2001 with 1.5 weightage to urban sector subject to the restriction that urban sample size for bigger states like Maharashtra, Tamil Nadu etc. should not exceed the rural sample size. Earlier practice of giving double weightage to urban sector has been modified considering the fact that there has been considerable growth in urban population. A minimum of 8 FSUs will be allocated to each state/UT separately for rural and urban areas.
Allocation to strata:
Within each sector of a State/UT, the respective sample size will be allocated to the different strata in proportion to the stratum population as per census 2001. Allocations at stratum level will be adjusted to a multiple of 4 with a minimum sample size of 4.
Selection of FSUs
FSUs will be selected with Probability Proportional to Size With Replacement (PPSWR), size being the population as per Population Census 1991 in all the strata for rural sector except for stratum 1. In stratum 1 of rural sector and in all the strata of urban sector, selection will be done using Simple Random Sampling Without Replacement (SRSWOR). Within each stratum, samples will be drawn in the form of two independent sub-samples in both the rural and urban sectors.
Selection of hamlet-groups/sub-blocks/households - important steps
Proper identification of the FSU boundaries: The first task of the field investigators is to ascertain the exact boundaries of the sample FSU as per its identification particulars given in the sample list. For urban samples, the boundaries of each Urban Frame Survey (UFS) block may be identified by referring to the map corresponding to the frame code specified in the sample list (even though map of the block for a latter period of the UFS might be available).
Criterion for hamlet-group/sub-block formation: After identification of the FSU, it is to be determined whether listing will be done in the whole sample FSU or not. In case the population of the selected village or block is found to be 1200 or more, it will be divided into a suitable number (say, D) of „hamlet-groups? in the rural sector and „sub-blocks? in the urban sector as stated below.
less than 1200 (no hamlet-groups/sub-blocks) 1
1200 to 1799 3
1800 to 2399 4
2400 to 2999 5
3000 to 3599 6
…………..and so on
For rural areas of Himachal Pradesh, Sikkim, Nagaland and Poonch, Rajouri, Udhampur, Doda districts of Jammu and Kashmir and Idukki district of Kerala, the number of hamlet-groups will be formed as follows.
approximate present population of the sample village no. of hgs to be formed
less than 600 (no hamlet-groups) 1
600 to 899 3
900 to 1199 4
1200 to 1499 5
.………..and so on
Two hamlet-groups/sub-blocks will be selected from a large village/UFS block wherever hamlet-groups/sub-blocks have been formed, by SRSWOR. Listing and selection of the households will be done independently in the two selected hamlet-groups/sub-blocks.
Formation of hamlet-groups/sub-blocks: In case hamlet-groups/sub-blocks are to be formed in the sample FSU, the same should be done by more or less equalizing population (details are in Chapter Two). Note that while doing so, it is to be ensured that the hamlet-groups/sub-blocks formed are clearly identifiable in terms of physical landmarks.
Listing of households: Having determined the hamlet-groups/sub-blocks, i.e. area(s) to be considered for listing, the next step is to list all the households (including those found to be temporarily locked after ascertaining the temporariness of locking of households through local enquiry). The hamlet-group/sub-block with sample hg/sb number 1 will be listed first and that with sample hg/sb number 2 will be listed next.
Formation of Second Stage Strata and allocation of households for Schedule 25.0
In each selected village/block/hamlet-group/sub-block, four second stage strata (SSS) will be formed as given below.
SSS 1: households with at least one member hospitalised during last 365 days
SSS 2: from the remaining households, households having at least one child of age below 5 years
SSS 3: from the remaining households, households with at least one member of age 60 years or above
SSS 4: other households
Selection of households for Schedules 1.0, 10 and 25.0
From each SSS the sample households for all the schedules will be selected by SRSWOR. If a household is selected for more than one schedule only one schedule will be canvassed in that household in the priority order of Schedule 1.0, Schedule 10 and Schedule 25.0 and in that case the household will be replaced for the other schedule. If a household is selected for Schedule 1.0 it will not be selected for Schedule 10 or Schedule 25.0. Similarly, if a household is not selected for Schedule 1.0 but selected for Schedule 10 it will not be selected for Schedule 25.0. However, for the household, selected from SSS1 of Schedule 25.0, the Schedule 25.0 will be canvassed even if the household is selected for other schedules.