However, because of the strong first factor, the substantial correlation of all items with this latent variable, and the low prevalence of the items related to the second factor, we considered perceived chewing ability as a construct that could be characterized by a summary score.
The prevalence of deleted items reported in the qualitative phase of the study was examined to assess the appropriateness of reinstating any removed items and to assist item merger decisions.
Table 3 shows the self-reported prevalence of the items relating to going from school to full-time education or university, and gaining qualifications through study as an adult.
The prevalence of six item ADL dependence and five item ADL dependence was estimated to allow comparison with prevalence of ADL disability reported in other studies.
In a first analysing step, four scientists independently evaluated the ratings a – e by patients and doctors, and additionally the prevalence of each item (f), and formed an individual opinion about recommendation of every single item for enclosure in MAGIC.
Table 1 shows the prevalence of each item as determined from the medical records and the comorbidity questionnaire and the level of agreement between them.
The lowest prevalence of the item "having permission to prepare a simple dish most of the time" was observed in Italy (8.9%), whereas in other countries this proportion exceeded 30%, with the highest percentage reported in Lithuania (51.2%).
Among people aged 60 years and over the prevalence of 5 item ADL disability was 11% in our study, similar to 12% in India (10% when age standardized) [ 15], and 8% in Shanghai, China[ 19].
Disability prevalence rates in Malaysia appear comparable to rates in other developing countries: For example, among people aged 65 and older, the prevalence of 5 item ADL disability in Sri Lanka was 10%17%7% when age standardised) which is almost identical to the 16% prevalence in our study [ 18].
However, the prevalence of six item ADL disability among r people age 60 years and above [ 12], and among people age 75 years and above, in Latin America and the Caribbean appears to be similar to the prevalence rates in our Malaysian study[ 13].
