3.1 Study design
3.1.1 Sampling frame Target population
The target population comprised adults aged 18–44 years who were registered with one or more disability service organisations that represent people with diabilities in South Australia.
There are twenty-one such organisations that range in scope from institutions that house and/or provide care for large numbers of people with disabilities (eg. Minda Inc., representing 255 adults with disabilities) through to self-help groups (eg. Community Living Project Inc., representing 26 adults with disabilities). The latter represent people with disabilities themselves and parents, family members and others who care for them, thereby reflecting the living arrangements of many people with disabilities who live at home. A two-stage sampling methodology was used, first to select appropriate organisations, and second to sample people with disabilities registered with those organisations.
Inclusion criteria
Organisations that represent specific disabling conditions were selected during the first stage of sampling. The conditions selected were those where partial or complete assistance for oral care typically is required from their carers. These conditions were also noted to be the most prevalent and needing more regular/daily support in the physical and intellectual disability categories among the 18–44 age-group in the South Australian Survey of Disability Prevalence 1996–1997 (Taylor et. al, 1998).
To achieve this, organisations interacting with care recipients with one or more of the following conditions were selected for inclusion in the study.
36 1. Autism
2. Brain injury 3. Cerebral palsy 4. Intellectual disability 5. Spina bifida
6. Quadriplegia
Exclusion criteria
Musculo-skeletal conditions like arthritis and muscular dystrophy were excluded as these conditions are more prevalent in individuals above the age of 44 years.
3.1.1.1 Sampling organisations associated with people with disabilities
As a sampling frame of people with physical and intellectual disabilities is not available in South Australia, information was obtained from the Disability Information and Resource Centre and Community Information Strategies Australia Inc. A list of all known disability organisations in Adelaide that provides accommodation and/or support services to adults with disabilities was constructed. Beginning in August, 2004, the chief administrator of each organisation was then contacted by phone to explain the purpose of the study and to seek assistance of the organisation in contacting people with disabilities registered with them as care recipients. Over a one-month period, twenty-one organisations were identified. They were approached with an introductory letter (Appendix 1) and were requested to provide information on the number and type of care recipients they interact with and indicate whether their organisation was willing to participate in the selection process. Twelve of them agreed to participate. From the information from the organisations, there were 1448 care recipients in the 18–44 years old age-group living in the community, institution or with families. They reported care recipient populations that ranged from 9 people (Individual Supported Accommodation Service Inc.) to 391 people (Autism SA). The organisations were categorised into three strata according to the type of care recipients they interact with: i) those living at family homes; ii) those living in community housing; or iii) those living in institutions.
3.1.1.2 Sampling people with disabilities for mail questionnaire
Beginning in February 2005, participating organisations were asked to send an information package to the primary carer of each registered care recipient in their database, with envelopes
37
headed “To the carer of” each care recipient. The cover letter specified that the questionnaire was to be completed by the primary (key) carer (Appendix 2).
The following materials were included inside the envelope:
• an information sheet on the study for the carer (Appendix 3)
• an information sheet on the study for the care recipient (Appendix 4)
• an information sheet on ‘Contact for information on project and independent complaints procedure’ from The University of Adelaide Human Research Ethics Committee (Appendix 5)
• a questionnaire for the carer (Appendix 6)
• consent forms for the care recipient (Appendix 7) and for the parent or guardian or person responsible (Appendix 8) for an oral examination of the care recipient (see further information in 3.2.2, below); and
• a reply-paid envelope addressed to the researchers at The University of Adelaide for the return of completed questionnaire and consent form.
When questionnaires were returned to the researchers, they were logged and on two-week intervals, organisations were sent a list of those respondents. Organisations then removed those names from their survey mailing list, and sent a reminder card (Appendix 9) after two weeks and a final follow-up letter (Appendix 10) after four weeks to any sampled care recipient for whom the carer had not responded. In a few cases there were two responses for the same care recipient from two carers at different organisations as the care recipient was associated with both the organisations. In such cases the “more complete” questionnaire was selected.
3.1.1.3 Sampling people with disabilities for oral epidemiological examinations
When all reminder and follow-up questionnaires had been returned, all respondents who provided consent were contacted to arrange an oral examination. This included calls at different times of the day and follow-up calls when they failed to attend, with up to five re- appointments.
Justification
Age was limited to 18 and 44 years of age to represent the adult population. Furthermore, selecting this age-group would provide access to a range of carers, including siblings, parents, partners and other carers and include care recipients living in different residential settings.
However, this sampling method excludes people who are not registered with a disability organisation, for example, people with disabilities who are cared for by a parent who is not a member of any of the listed organisations.
38 3.2 Data collection