The 2018 Tonga National Disabiltiy Survey was conducted jointly by the Tonga Department of Statistics (TDS) and the Ministry of Internal Affairs, Social Protection and Disability. It is the first population-based comprehensive disability survey in the country. Funding was provided through number of bodies including UNICEF, DFAT and Tonga Government. The Pacific Community provided technical supports through out different stages of the survey.

The main purpose of the survey is to desctibe demographic, social and economic characteristics of persons with disabilities and detemine the prevalence by type of disability in Tonga, and thus help the government and decision makers in formulating more suitable national plans and policies relevant to persons with disabilities.

The other objectives of the Disability survey were collect data that would determine but not limited to the following: a. Disability prevalence rate at the national, urban and rural based on the Washington Group recommendations; b. degree of activity limitations and participation restrictions and societal activities for persons with disability: c. ascertain the specific vulnerabilities that children and adults with disability face in Tonga d. establish the accessibility of health and social services for persons with disability in Tonga e. generate data that guides the development of policies and strategies that ensure equity and opportunities for children and adults with disabilities.

An additional module was included to collect information on people's perception/experiences of service delivery of Goverment to the public.

Version 01: Clean, labelled and de-identified version of the Master file.

The scope of the study involves Disability. Various sections of the Questionnaire are listed below.

HOUSEHOLDS:
-Basic household characteristics of the private dwellings, including sanitation, water, electricity, households materials and household wealth;

INDIVIDUALS:
-Basic demographic characteristics of individuals in a particular household dwelling, including age, sex, ethnicity, religion, marital status, educational attainment, and economic activity

(Children aged 2-4 years:
-Level of difficulty functioning by domain, tools and supports, age of onset of difficulty, cause of difficulty, health, transport;)

(Children aged 5-17 years:
-Level of difficulty functioning by domain, tools and supports received, age of onset of difficulty, cause of difficulty, health, transport, education, employment, income, participation and accessibility)

(Adult aged 18 years and older:
-Level of difficulty functioning by domain, tools and supports received, age of onset of difficulty, cause of difficulty, health, transport, education, employment, income, participation and accessibility).

• Collection start: 2018
• Collection end: 2018

Abstract

The 2018 Tonga National Disabiltiy Survey was conducted jointly by the Tonga Department of Statistics (TDS) and the Ministry of Internal Affairs, Social Protection and Disability. It is the first population-based comprehensive disability survey in the country. Funding was provided through number of bodies including UNICEF, DFAT and Tonga Government. The Pacific Community provided technical supports through out different stages of the survey.

The main purpose of the survey is to desctibe demographic, social and economic characteristics of persons with disabilities and detemine the prevalence by type of disability in Tonga, and thus help the government and decision makers in formulating more suitable national plans and policies relevant to persons with disabilities.

The other objectives of the Disability survey were collect data that would determine but not limited to the following: a. Disability prevalence rate at the national, urban and rural based on the Washington Group recommendations; b. degree of activity limitations and participation restrictions and societal activities for persons with disability: c. ascertain the specific vulnerabilities that children and adults with disability face in Tonga d. establish the accessibility of health and social services for persons with disability in Tonga e. generate data that guides the development of policies and strategies that ensure equity and opportunities for children and adults with disabilities.

An additional module was included to collect information on people's perception/experiences of service delivery of Goverment to the public.

Geographic coverage

National and island division coverage.

There are six statistical regions known as Divisions in Tonga namely Tongatapu urban area, Tongatapu rural area, Vava'u, Ha'apai, Eua and the Niuas.Tongatapu Urban refers to the capital Nuku'alofa is the urban area while the other five divisions are rural areas. Each Division is subdivided into political districts, each district into villages and each village into census enumeration areas known as Census Blocks.

Analysis unit

• Individuals
• Households.

Universe

The survey covers all usual residents of selected households, all children 2-17 years and adults 18 years and above and undertake comparisons between persons with and without disability.

Kind of data

Sample survey data [ssd]

Sampling procedure

SAMPLE SIZE: the total number of households to interview approximates 5,500 households based on the budget allocation available

SELECTION PROCESS: the selection of the sample is based on different steps (see previous section)

Stratification: this sample design is a stratified multi stage random survey. Stratification happened based on the disability status of the households and their geographical residence.

STAGES OF SELECTION: - the first stage of selection focussed on the selection of Enumeration Areas or Census Blocks as Primary Sampling Unit for households with disability. In total 334 PSUs have to be selected in order to cover the expected sample size. - the stage 2 of the selection concerns only the households with no disability as all households with disability from the selected EA are selected for interview

Level of representation: The survey will provide a comparison of the status between households with and without disability at the island group level.

REPLACEMENT: All non-response have been replaced according to the disability status of the household. Disable households that had to be replaced were replaced by another household with disability from the closest block.

SAMPLING FRAME: The sampling frame used was the 2016 population census. No additional listing were conducted.

The Sampling strategy is designed consistently with the purpose of the survey. The purpose of the 2018 Tonga Disability Survey is not to estimate the prevalence of disability in Tonga, which has been done on a very accurate way in the 2016 Population Census, but to compare the situation of the household with disability with the situation of households with not disability across the 6 geographical zones of Tonga.

The sampling strategy of the 2018 Tonga Disability Survey is based on 2 stages stratified random sample.

The stratification carried out in this survey is based on the disability status of the household: - strata 1: households who declared at least 1 member in disability (according to Washington Group list of question) - strata 2: households who did not report any disability member

The sampling frame used in this survey is the 2016 National Population Census that included the set of question on disability (from the Washington Group). In addition to the first set of stratification, the geographical breakdown of Tonga (by 6 island groups) has to be taken into consideration.

The overall idea is to equally split the total sample in both strata (1 & 2), which has been allocated to approximatively 5,500 households.

A replacement procedure is implemented in case of non -response.

The first step is to identify the households with disability from the population census. Households with disability are the households who reported at least 1 member as disable according to the 6functionning domains recommended by the Washington Group (see, hear, walk, remember, self-care, communicate).

In the strata 1, the sample distribution of approximatively 2,750 households was allocated using the square roots distribution of households across the 6 island groups. The next step consists in determining the number of blocks (Enumeration Areas) to select as Primary Sampling Unit. Again, by getting from the census frame the average number of households with disability in each block by island group will generate the number of blocks to select as PSU. Within each selected block, all households with disability will be selected for interview.

The strategy for strata 2 (non disable households) is to use the same blocks that have been selected for households in strata 1 and interview within those blocks the same number of households as strata 1.

Here is the final sample - after selection: Tongatapu urban: 1336
Tongatapu rural: 1884
Vava'u: 1060
Ha'apai: 550
Eua: 352
Niua: 54
TOTAL: 334

EA SELECTION (Primary Sampling Units labelled as blocks in the 2016 Tonga census): The EA were selected using probability proportional to size (size means number of households with disability within the EA). Within all selected EAs, all households with disability are selected for interview, and the same number of household with no disability. Households with no disability to interview in the EA were randomly selected, using uniform probability of selection.

Sampling deviation

Deviation from the original sampling plan was observed due to challenges in the field: The main fieldwork challenge was to trace the selected households (that were selected from the 2016 census frame) especially after cyclone Gita that hit Tonga before the field operation. Geography and composition of households have changed (and the household listing was not updated).

Under those circumstances, the total number of households interviewed has changed. Here is the percentage of modification between the original sampling plan and the survey achievements for each of the 2 stratas:

-STRATA 1: Tongatapu urban: 5% Tongatapu rural: 3% Vava'u: 6% Ha'apai: 0% Eua: -10% Niua: 103% Total: 4%

-STRATA 2 Tongatapu urban: 6% Tongatapu rural: 5% Vava'u: 2% Ha'apai: 1% Eua: 1% Niua: 133% Total: 5%.

Mode of data collection

Computer Assisted Personal Interview [capi]

Research instrument

Tonga Disability Survey 2018 used the CAPI system for the interview. However, the questionnaire was developed manually using excel and word software. The questionnaire was then converted to the CAPI using the Survey Solutions software. The questionnaire has two parts - the household and personal questions.

The Household questionnaire containing questions asking about characteristics of all household members of and about the household characteristics. It contains the following parts: · Household schedule/roster - listing all members and recording other social and economic information · Household characteristics - ask about household structure, characteristics, goods, assets and income.

The Personal questionnaire contains questions asking about child functioning among young children (aged 2-4 years) and older children (aged 5-17 years). Questions on adult functioning are also asked of adult aged 18 years and above. The personal questionnaire includes the following sections: · Young Child functioning for children aged 2-4 years old · Older child functioning for children aged 5-17 years old · Adult functioning for persons aged 18 years and older · Tools and service (2 years and above) · Needs and availability (2 years and above) · Transport (2 years and above) · Health care and support (5 years and above) · Education (5 years and above) · Employment and income (15 years and above) · Participation and accessibility (15 years and above) · Other social issues (18 years and above).

The development of the questionnaire went through several consultations and review from key partners and stakeholders within and outside Tonga including Tonga National Statistics Office, Non disability and disability offices in Tonga, UNICEF, WG, PDF, UNESCAP and SPC. Though the questionnaire was originally developped in English, it was also translated to Tongan local language. The first draft of the questionnaire was tested during the Pilot training and fieldwork. The questionnaire is provided as an external resource.

The draft questionnaire was pre-tested during