In-flight upset - 154 km west of Learmonth, WA, 7 October 2008,

The questionnaire respondents were compared to the other adult passengers todetermine the extent to which the survey sample was representative. 226 Thecomparison indicated that:• There was no apparent difference between survey respondents and other adultpassengers in terms of the proportion of males and females.• There was no statistical difference between the proportion of adult passengerswho responded to the questionnaire from the front (12/27, 44%), centre (48/141,34%) or rear sections (38/109, 35%) of the aircraft. After accounting for the24 adults who were not contacted (1, 13 and 10 in front, centre and rear), theresponse rates were 46%, 38% and 38%.• A higher proportion of the adult passengers completed the questionnaire fromAustralia (43%) and European countries (39%) compared to passengers fromAsian countries (26%). After accounting for the 24 adults who were notcontacted, the response rates were 42%, 47% and 29% respectively.• A higher proportion of passengers aged over 45 (44%) completed thequestionnaire compared to passengers aged 18 to 45 (26%). Most of those whowere not contacted were above 45.• Overall, there were reasonable proportions of survey respondents from eachsection of the aircraft, and there were reasonable proportions of respondentsfrom the major demographic groups present on the occurrence flight.There was no evidence that passengers who were injured were more likely tocomplete the questionnaire. The proportion of questionnaire respondents whoreceived hospital medical treatment (18%) was no different to the proportion ofother adult passengers who received hospital medical treatment (17%).226Statistical comparisons were done using the χ 2 (Chi squared) test for independent groups. In thisreport, ‘statistically significant’ means that the chance of the difference being present due tochance alone was less than 5%.- 270 -