Chapter 8. Design of the Main Survey Instruments
The process of designing the NDA Questionnaire involved at the outset carrying out an in depth literature search of international instruments and methodological papers of recent years. The literature search produced many papers addressing methodological issues in the area of disability/activity limitation, which served to aid our design and planning process. A key aspect to the design process for us was how best to link the newest ICF Classification into our questionnaire in terms of the elements to choose and the level of detail necessary.
8.2 Review of Surveys
Initial designing of the disability questionnaire began with an analysis of international questionnaires. (A list of the instruments consulted is provided in Appendix 1). Three surveys were particularly important in the design of our questionnaire. These were the Survey of Disability, Ageing and Carers 2001, undertaken by the Australian Bureau of Statistics; the PALS 2001 Survey, undertaken by Statistics Canada and the New Zealand Household Disability Survey 2001, undertaken by Statistics New Zealand. A flavour of these surveys is provided below. All three surveys were analysed based on their content with regard to ICF chapters and domains and question typology. Broad categories based on the ICF domains were developed including:
- Learning and Mental Functioning
- Self Care & Domestic Life
- Main Health Condition
- Use of aids or specialised equipment
- Social Participation
- Transport and Education
The ICF was used as a conceptual framework in this design process. With the help of the consultation process decisions were made on the broad levels to be included.
For each category each survey was examined in terms of its inclusion/omission/ ICF classification and question typology. The questions spanned the components of functioning (Body Functions, Activities, Participation and Environmental Factors). As we wanted to target children (up to 15) influenced by international practices in this regard it was decided that this information would best be captured by devising a separate questionnaire for children.
Australian Bureau of Statistics – Survey of Disability, Ageing and Carers, 2001.
This survey measures information on people with disabilities, older people and people who provide assistance to others because of their disabilities. Information was recorded for adults and children. Information collected with regard to disability included such activities as self-care, mobility, communication, impairments and restrictions.
In 1998, 3.6 million people in Australia had a disability (19% of the total population). A further 3.1 million had an impairment or long-term condition that did not restrict their everyday activities. Of those with a disability, 87% (3.2 million) experienced specific restrictions in core activities, schooling or employment.
Statistics New Zealand – Household Disability Survey 2001
Statistics New Zealand carried out a second national household survey of disability in 2001. The first survey was carried out in 1996-1997. The new ICF disability classification was not used in the 2001 survey rather the older definition which had been used in the previous round was used instead for comparability purposes.
The sample size for the 2001 Household Disability Survey was 38,508 people. The achieved response rate was 73 percent. The total number of respondents with disabilities was 7,256; these were: 2,055 children; 3,483 adults aged 15 to 64 years; and 1,718 seniors aged 65 years and over.
The 2001 Household Disability Survey used four questionnaires. Adult and child screen questionnaires were firstly carried out to establish whether or not they had a disability according to the definition applied. Adults (aged 15 and over) and children (under 15) who fulfilled the criteria then completed an adult or child questionnaire. The questions related to services and assistance, employment, education, transport, accommodation, special equipment and economic characteristics. Two similar, but separate, questionnaires were completed for children aged 0 to 14 years who were selected to participate in the survey.
Statistics Canada Participation and Activity Limitation Survey (PALS) 2001
PALS is a post-censal survey, using the 2001 Census as a sampling frame to identify its population, designed in the light of the ICF. Two general questions on activity limitations were included on the 2001 Census and a sample of individuals who answered ‘yes’ to the activity limitation questions on the census form was selected.
The PALS sample was 43,000, consisting of approximately 35,000 adults and 8,000 children. The interviews were conducted by telephone. Two questionnaires were used, one for adults aged 15 and over and one for children under 15. The interviews for the children’s questionnaire were conducted with the parent or guardian of the child. The overall response rate was 82.5%.
8.3 Structure of Adult and Child Questionnaires
The structure of the adult and child questionnaires we developed were broadly similar. Both questionnaires contained each of the seven sections as outlined in Table 14 below. (The full questionnaires are given in Appendix 3 and 4 respectively) The main areas of differences between the two instruments related to issues such as marital status; labour market experience; transportation and driving; and intellectual development (extra questions added on this latter point on the child questionnaire).
|Section||Questions||Component||Adult Questionnaire||Child Questionnaire|
|1||A1 to A10||Activities & Aids||Seeing||Seeing|
|1||B1 to B12||Activities & Aids||Hearing||Hearing|
|1||C1 to C8||Activities & Aids||Speaking||Speaking|
|1||D1 to D12||Activities & Aids||Mobility / agility||Mobility / agility|
|1||E1 to E5||Activities & Aids||Pain||Pain|
|1||F1 to F6||Activities & Aids||Breathing||Breathing|
|1||G1 to G9||Activities & Aids||Learning||Learning|
|1||H1 to H3||Activities & Aids||Intellectual / development||2 extra questions|
|1||J1 to J3||Activities & Aids||Memory||Memory|
|1||K1 to K3||Activities & Aids||Emotional, psychological, mental health||Emotional, psychological, mental health|
|1||L1 to L4||Activities & Aids||Any other difficulty (specify)||Any other difficulty (specify)|
|2||M1 to M18||Help from other people & attitudes of other people|
|3||N1 to N15||Background to reduction in activities|
|4||P1 to P14||Major Life Areas||Education||Education - extra questions on educational needs assessment|
|4||Q1 to Q35||Major Life Areas||Employment||Employment - no questions|
|4||R1 to R7||Major Life Areas||Leisure & social participation||Leisure & social participation|
|4||S1 to S17||Major Life Areas||Transport||Transport - driving questions excluded|
|4||T1 to T17||Major Life Areas||Housing||Housing|
|5||U1 to U16||Demographic Information||Marital status excluded|
|6||V1 to V6||Feedback from Respondent|
|7||W1 to W6||Feedback from Interviewer|
As well as using the ICF as a conceptual framework to guide our design we also use it as a set of classifications. From Table 15 one can see the domains under each of the main components (Body functions and Structure A &P and Environmental Factors) the chapter, block and the broad 2 level 3 digit code.
On the main questionnaires, the ICF classification (without the qualifier) is printed in small font after each item that has a clear ICF counterpart (see Appendix 3 and Appendix 4). Since the relevant environmental factors tend to be specific to a particular set of circumstances, they are distributed throughout the questionnaire rather than forming a clear block of items. For instance, items A8 to A10 deal with aids or services that might be used by someone with a visual impairment; items D10 to D12 cover aids or services likely to be of benefit to someone with a mobility impairment.
|Component||Sub-component||Chapter||2nd Level Code||Classification|
|Body functions & structures||Vision||2||b210-b220||Seeing & Related Functions|
|Body functions & structures||Hearing||2||b230-b240||Hearing & Vestibular Functions|
|Body functions & structures||Speech||3||b310-b340||Voice & Speech Functions|
|Body functions & structures||Breathing||4||b440-b460||Functions of Respiratory System|
|Body functions & structures||Pain||2||b280||Pain|
|Activities & participation||Communication||3||d310 - d345||Communication Receiving-Producing|
|Activities & participation||Mobility||4||d450-d465||Walking and moving|
|Activities & participation||Agility||4||d430 - d445||Carrying, Moving & Handling Objects|
|Activities & participation||Self care||5||d510 - d570||Self Care|
|Activities & participation||Major life areas - education||8||d810 - d839|
|Activities & participation||Major life areas - employment||8||d840 - d859|
|Activities & participation||Leisure & social participation||9||d920|
|Environmental factors||Products & technology||1||e110 - e199|
|Environmental factors||Support & relationships||3||e310 - e399|
|Environmental factors||Attitudes||4||e410 - e499|
|Environmental factors||Services, systems & policies||5||e510 - e599|
As can be seen in Table 16, of the 143 people who said in the filter that they would take part 43 individuals (30 per cent) did not actually participate for a variety of reasons (mostly refusals) while 106 individuals (74 per cent) went on to complete the main survey. This figure was made up of 93 adults and 13 children.
* 93 adults and 13 children
8.4 Piloting the Main Questionnaires
The main survey was implemented on a personally administered basis by interviewers visiting the respondents in their own home. In general, the experience of the pilot indicated a very positive response to the survey with very few problems arising.
Profile of (93) Adults
Table 17 indicates that the gender breakdown of adults interviewed was 58 per cent females, 42 per cent males.
An analysis of the age breakdown of the 93 participating adults is shown in Table 18. This indicates that 79 per cent of the sample was 45 yrs or over. The 45 to 64 age cohort accounted for the largest proportion overall (44 per cent), while the youngest age category (22 to 34yrs) accounts for the smallest proportion of adults surveyed (9 per cent).
Table 19 shows that 60 per cent of respondents were married. Widow/widowers account for 17 per cent of the sample, while single people make up 16 per cent, 5 per cent are separated and only one person was recorded as divorced.
Results from the Profile Sheet for Adults
In the course of each questionnaire the interviewer filled out a profile sheet which summarised the 11 broad categories in which the respondent reported having some level of difficulty. These broad categories are as follows:
- emotional/psychological/mental health and
- any other activity limitation.
From Table 20 one can see that in general the type of activity limitation recorded most frequently was that of generic pain (77 per cent); this is followed closely by limitations in terms of mobility/agility, just one third of respondents identify breathing as a cause of activity limitation, nearly 30 per cent identified difficulties in hearing, 26 per cent can be seen to have some form of emotional psychological or mental health difficulty, while 24 per cent have difficulties in seeing. Between 4 to 11 per cent of adult respondents record difficulty with intellectual, developmental, learning and speaking.
|Emotional, Psychological, Mental Health||24||26|
|Any other difficulty||27||29|
Number of Activity Limitations experienced
As can be seen from the Table 21 a total of 3 per cent of respondents record no activity limitation. This can be explained by the fact that, as in the filter questionnaire, the main instrument recorded details on activity limitations and also participation restrictions; in effect this meant that a respondent could experience a) an activity limitation only; b) a participation restriction only or c) a combination of both. The 3% who reported experiencing no limitation in any of the 11 categories fall into the group - i.e. those who experience only participation restrictions. Just under half of respondents record an incidence of between 2 to 3, just over a quarter of respondents record the incidence of between 4 to 6 activity limitations, only 4 per cent (2) of respondents recorded between 7 or 8.
|Number of Activity Limitations||Number of Respondents||% of Respondents|
In order to take account of the degree or intensity of difficulty experienced by respondents an intensity scale was developed. Altogether we had 11 disability types (10 distinct types and one miscellaneous “other” category). If the respondent recordedhaving a difficulty in any of the 11 disability types, the respondent was then asked to rate the level of difficulty which he/she experienced under one or more functional limitation categories associated with that disability. The nature of functional limitations varied as between one disability and the other.
For example, in the adult questionnaire 3 types of functional limitation was assessed for ‘hearing’ namely:
- B2: Hearing what is said in a conversation with ONE other person
- B3: Hearing what is said in a conversation with at least three other people, and
- B4: Hearing what is said in a telephone conversation.
Another example is provided in the area of ‘Mobility/Agility’ where a total of 7 functional limitations were assessed:
- D1: walking for short distances, such as walking around rooms or hallways or for short distances outside
- D2: walking up and down a flight of stairs, about 12 steps without resting
- D3: moving form one room to another
- D4: getting into and out of bed
- D5: lifting or carrying something like a cup or a bag of groceries
- D6: bending down and picking up an object from the floor
- D7: difficulty using your fingers to grasp or hold an object
Table 22 provides a breakdown of the number of functional limitations measured in each activity limitation category. A total of 20 functional limitations was assessed in terms of the respondents perception of their level of difficulty.
|Activity Limitation||Functional Limitations|
|Emotional, Psychological, Mental Health||1|
|Any other difficulty||1|
The respondent could choose one from the response scale below (none to cannot do) to indicate the level of difficulty experienced in each of the 20 functional limitation categories:
|Response Scale||Points attributed to each response|
|a little difficulty;||1|
|a moderate level of difficulty;||2|
|a lot of difficulty;||3|
A score ranging from 0 – 4 was attributed in relation to each of the 20 functional limitations depending on the response given. The intensity score for each functional limitation across all respondents was then calculated as the mean score across each functional limitation. For adult respondents the intensity scale ranged from 0 to 2.3 points. These can be grouped into 4 categories as follows:
|Mild||between 0.01 to 0.30|
|Moderate||between 0.31 to 0.60|
|Severe||between 0.61 +|
The results are outlined in Table 23. From this one can see that 9 per cent of adults (representing 8 persons) record a zero score on the intensity scale. These are individuals who recorded no activity limitation but who did indicate some form of participation restriction. The table shows that 24 per cent of respondents had “mild” score on the intensity scale (between 0.01 to 0.3); 29 per cent had a moderate score and the remaining 38 per cent had a “severe” score .
Intensity of Adult Activity Limitation by Gender and Age
Tables 25 and 26 provide a breakdown of adult respondents in terms of intensity scores according to gender, and age cohort. The breakdown by gender indicates little difference in intensity between males and females. As one might expect, intensity increases with age.
|Male||4 (10%)||7 (18%)||13 (33%)||15 (38%)||39 (100%)|
|Female||4 (7%)||15 (28%)||14 (26%)||21 (39%)||54 (100%)|
|Total||8 (8%)||22 (24%)||27 (29%)||36 (39%)||93 (100%)|
|22-34||0 (0%)||2 (25%)||3 (38%)||3 (38%)||8 (100%)|
|35-44||1 (9%)||6 (54%)||2 (18%)||2 (18%)||11 (100%)|
|45-64||3 (7%)||9 (22%)||11 (27%)||18 (44%)||41 (100%)|
|65+||4 (12%)||5 (15%)||11 (33%)||13 (39%)||33 (100%)|
|Total||8 (9%)||22 (24%)||27 (29%)||36 (39%)||93 (100%)|
Profile of Children
Nine of the children interviewed in the main survey were male and 4 were female. With regard to age, Table 27 shows that the largest age cohort represented was 10-15 yrs, this was followed closely by 6-9 yr olds the lowest age cohort 3-5yrs accounted for the smallest proportion.
Table 28 shows that disabilities/difficulties associated with children were more generally characterised as being related to hearing and developmental issues as well as communications.
|Emotional, Psychological, Mental Health||3|
|Any other difficulty||6|