Electronic Supplementary Material
Appendix 1 Deletions by criterion: their rationale and distribution
Screening responses for quality data from online surveys is best done using a mixture of methods [1]. The first exclusion criterion was that the answers provided to any of the three questions differed by more than one level on the four response level scale. This criterion was used as consistency of response to duplicate questions is an accepted indicator of respondent veracity. A one level difference in responses was deemed to be acceptable as the questions asked in between duplicates may have altered a person’s perception (a ‘priming’ effect).
People whose utility scores differed by more than 0.5 on the two instruments were also excluded. Both instruments were calibrated using the time trade off (TTO) method. A reduction in the TTO of 0.5 is therefore equivalent to a preference to sacrifice 50 percent of life. If a person varies the evaluation of themselves by this amount the probable explanation is the unreliability of the response, not the difference in the instruments which correlate highly (see Appendix 4).
Respondents claiming an educational attainment of ‘part primary school’ were also excluded. This response category was included as an addendum to the ASCED levels used by the Australian Bureau of Statistics [2]. Putting an illegitimate response category in a survey is an accepted technique for identifying poor quality data [1].
Table A1.1 reports the number of cases deleted by criterion. Table A1.2 reports the total number of respondents by demographic and AQoL-4D cell and the distribution of the deletions, which are shown in brackets.
Table A.1.1 Cases deleted by criterion (original n=3408)
Criterion / Number / Action1.Comparison of 3 questions reported in AQoL-4D, AQoL-8D (family role, communication, pain)
All 3 answers inconsistent
2 of 3 answers inconsistent
1 answer inconsistent by more than 1 response level / 53
179
189 / Deleted
Deleted
Deleted
2.AQoL-8D and AQoL-4D differed more than 0.5 / 7 / Deleted already by Criterion 1
3. Age and year of both inconsistent (more than +1 year) / 69 / Deleted
4. Stated education part primary (legally impossible) / 7 / Deleted
Total deletions
Retained n
Percent deletions / 497
2731
15.4
Note: 180 participants indicated they were aged over 75 and were not analysed for the norms - analysed n=2731
Table A1.2 Cell count by retained and deleted responses
Aqol4Dscore Range-0.04 thru <0.2 / 0.2 thru <0.4 / 0.4 thru < 0.6 / 0.6 thru <0.8 / 0.8 thru <1 / 1
Male / <18 / 1 (1) / 2 (3) / 4 / 3 (1) / 2 / 4 (2)
18-24 / 6 (16) / 6 (6) / 11 (7) / 15 (12) / 31 (6) / 20 (6)
25-34 / 10 (17) / 32 (19) / 22 (17) / 41 (9) / 45 (6) / 45 (5)
35-44 / 24 (7) / 37 (8) / 27 (9) / 41 (9) / 48 (3) / 45 (5)
45-54 / 35 (15) / 27 (10) / 41 (9) / 43 (7) / 48 (2) / 35 (2)
55-64 / 42 (8) / 46 (4) / 41 (9) / 45 (5) / 50 / 47 (3)
65-74 / 19 (17) / 35 (9) / 40 (10) / 45 (5) / 48 (2) / 49
Female / <18 / 3 / 4 (1) / 1 / 17 / 11 / 1
18-24 / 16 (5) / 15 (3) / 36 (8) / 43 (7) / 46 (6) / 15 (3)
25-34 / 33 (15) / 37 (13) / 42 (9) / 50 / 46 (4) / 42 (8)
35-44 / 29 (10) / 46 (4) / 44 (6) / 46 (4) / 47 (3) / 48 (2)
45-54 / 40 (9) / 45 (5) / 40 (10) / 47 (3) / 49 (1) / 48 (2)
55-64 / 41 (9) / 46 (5) / 47 (4) / 46 (3) / 48 / 45 (1)
65-74 / 12 (4) / 33 (2) / 46 (4) / 47 (3) / 50 / 25 (1)
Note: numbers in brackets are deleted cases
Appendix 2
Table A2.1 Dimension norms by age and gender weighted only to correct for self-selection (ie unweighted by utilities)
Physical DimensionsAge / Gender / Independent Living / Senses
Mean / Std. Err. / Std. Dev. / Mean / Std. Err. / Std. Dev.
16-24 / Female / 0.962 / 0.005 / 0.066 / 0.935 / 0.007 / 0.087
Male / 0.966 / 0.006 / 0.050 / 0.947 / 0.008 / 0.055
Total / 0.964 / 0.004 / 0.059 / 0.941 / 0.005 / 0.072
25-34 / Female / 0.959 / 0.005 / 0.090 / 0.935 / 0.006 / 0.084
Male / 0.955 / 0.005 / 0.080 / 0.938 / 0.006 / 0.085
Total / 0.957 / 0.004 / 0.085 / 0.937 / 0.004 / 0.085
35-44 / Female / 0.946 / 0.005 / 0.100 / 0.922 / 0.006 / 0.085
Male / 0.947 / 0.005 / 0.092 / 0.924 / 0.006 / 0.092
Total / 0.946 / 0.004 / 0.096 / 0.923 / 0.004 / 0.089
45-54 / Female / 0.938 / 0.006 / 0.117 / 0.885 / 0.006 / 0.095
Male / 0.930 / 0.007 / 0.124 / 0.880 / 0.008 / 0.107
Total / 0.934 / 0.005 / 0.121 / 0.883 / 0.005 / 0.101
55-64 / Female / 0.918 / 0.007 / 0.143 / 0.894 / 0.005 / 0.092
Male / 0.919 / 0.007 / 0.149 / 0.880 / 0.006 / 0.113
Total / 0.918 / 0.005 / 0.146 / 0.887 / 0.004 / 0.103
65-74 / Female / 0.898 / 0.009 / 0.177 / 0.886 / 0.006 / 0.110
Male / 0.910 / 0.008 / 0.169 / 0.871 / 0.007 / 0.130
Total / 0.904 / 0.006 / 0.174 / 0.878 / 0.005 / 0.120
Total / Male / 0.941 / 0.003 / 0.106 / 0.911 / 0.003 / 0.099
Female / 0.940 / 0.002 / 0.113 / 0.912 / 0.003 / 0.094
Total / 0.941 / 0.002 / 0.110 / 0.911 / 0.002 / 0.097
Pain / Physical Super Dimension (PSD)
16-24 / Female / 0.912 / 0.010 / 0.127 / 0.877 / 0.010 / 0.126
Male / 0.937 / 0.011 / 0.080 / 0.904 / 0.011 / 0.082
Total / 0.925 / 0.008 / 0.104 / 0.891 / 0.008 / 0.105
25-34 / Female / 0.900 / 0.010 / 0.166 / 0.871 / 0.010 / 0.156
Male / 0.906 / 0.010 / 0.133 / 0.874 / 0.010 / 0.134
Total / 0.903 / 0.007 / 0.149 / 0.872 / 0.007 / 0.145
35-44 / Female / 0.856 / 0.013 / 0.199 / 0.826 / 0.011 / 0.173
Male / 0.882 / 0.011 / 0.160 / 0.847 / 0.011 / 0.158
Total / 0.869 / 0.008 / 0.181 / 0.836 / 0.008 / 0.166
45-54 / Female / 0.841 / 0.012 / 0.220 / 0.795 / 0.011 / 0.194
Male / 0.836 / 0.014 / 0.208 / 0.787 / 0.013 / 0.195
Total / 0.839 / 0.009 / 0.214 / 0.791 / 0.008 / 0.195
55-64 / Female / 0.806 / 0.014 / 0.243 / 0.767 / 0.012 / 0.218
Male / 0.833 / 0.013 / 0.249 / 0.778 / 0.012 / 0.224
Total / 0.819 / 0.010 / 0.247 / 0.772 / 0.008 / 0.221
65-74 / Female / 0.771 / 0.015 / 0.274 / 0.732 / 0.013 / 0.243
Male / 0.805 / 0.014 / 0.264 / 0.749 / 0.012 / 0.245
Total / 0.788 / 0.010 / 0.271 / 0.740 / 0.009 / 0.245
Total / Male / 0.873 / 0.005 / 0.180 / 0.831 / 0.005 / 0.174
Female / 0.854 / 0.005 / 0.206 / 0.818 / 0.005 / 0.187
Total / 0.864 / 0.004 / 0.193 / 0.825 / 0.004 / 0.181
Psycho-social Dimensions
Age / Gender / Mental health / Relationships
Mean / Std. Err. / Std. Dev. / Mean / Std. Err. / Std. Dev.
16-24 / Female / 0.665 / 0.017 / 0.168 / 0.781 / 0.014 / 0.141
Male / 0.758 / 0.020 / 0.116 / 0.836 / 0.015 / 0.094
Total / 0.713 / 0.013 / 0.148 / 0.809 / 0.010 / 0.120
25-34 / Female / 0.667 / 0.013 / 0.166 / 0.793 / 0.012 / 0.153
Male / 0.706 / 0.013 / 0.151 / 0.803 / 0.012 / 0.141
Total / 0.686 / 0.009 / 0.160 / 0.798 / 0.008 / 0.147
35-44 / Female / 0.652 / 0.012 / 0.158 / 0.776 / 0.011 / 0.153
Male / 0.676 / 0.012 / 0.145 / 0.778 / 0.010 / 0.133
Total / 0.664 / 0.008 / 0.152 / 0.777 / 0.007 / 0.143
45-54 / Female / 0.650 / 0.011 / 0.164 / 0.767 / 0.010 / 0.156
Male / 0.697 / 0.013 / 0.174 / 0.783 / 0.012 / 0.166
Total / 0.673 / 0.009 / 0.171 / 0.775 / 0.008 / 0.162
55-64 / Female / 0.681 / 0.010 / 0.157 / 0.790 / 0.010 / 0.171
Male / 0.714 / 0.011 / 0.183 / 0.797 / 0.010 / 0.180
Total / 0.697 / 0.007 / 0.171 / 0.793 / 0.007 / 0.176
65-74 / Female / 0.720 / 0.010 / 0.169 / 0.807 / 0.010 / 0.178
Male / 0.744 / 0.010 / 0.187 / 0.827 / 0.010 / 0.187
Total / 0.732 / 0.007 / 0.179 / 0.817 / 0.007 / 0.183
Total / Male / 0.713 / 0.006 / 0.164 / 0.802 / 0.005 / 0.150
Female / 0.668 / 0.005 / 0.167 / 0.784 / 0.005 / 0.158
Total / 0.691 / 0.004 / 0.167 / 0.793 / 0.003 / 0.155
Coping / Self Worth
16-24 / Female / 0.817 / 0.013 / 0.146 / 0.795 / 0.015 / 0.160
Male / 0.899 / 0.011 / 0.074 / 0.881 / 0.014 / 0.089
Total / 0.859 / 0.009 / 0.114 / 0.839 / 0.010 / 0.129
25-34 / Female / 0.803 / 0.012 / 0.159 / 0.818 / 0.012 / 0.166
Male / 0.849 / 0.011 / 0.124 / 0.852 / 0.012 / 0.134
Total / 0.826 / 0.008 / 0.143 / 0.835 / 0.008 / 0.151
35-44 / Female / 0.799 / 0.010 / 0.149 / 0.829 / 0.010 / 0.155
Male / 0.815 / 0.009 / 0.128 / 0.846 / 0.010 / 0.135
Total / 0.807 / 0.007 / 0.139 / 0.838 / 0.007 / 0.146
45-54 / Female / 0.794 / 0.011 / 0.167 / 0.821 / 0.011 / 0.171
Male / 0.812 / 0.011 / 0.147 / 0.860 / 0.010 / 0.149
Total / 0.803 / 0.007 / 0.157 / 0.840 / 0.007 / 0.161
55-64 / Female / 0.824 / 0.009 / 0.151 / 0.855 / 0.009 / 0.153
Male / 0.839 / 0.009 / 0.163 / 0.889 / 0.008 / 0.150
Total / 0.831 / 0.006 / 0.157 / 0.871 / 0.006 / 0.153
65-74 / Female / 0.845 / 0.008 / 0.154 / 0.899 / 0.008 / 0.144
Male / 0.851 / 0.008 / 0.160 / 0.916 / 0.007 / 0.147
Total / 0.848 / 0.006 / 0.157 / 0.907 / 0.005 / 0.146
Total / Male / 0.844 / 0.004 / 0.135 / 0.870 / 0.005 / 0.139
Female / 0.811 / 0.004 / 0.157 / 0.831 / 0.005 / 0.165
Total / 0.827 / 0.003 / 0.147 / 0.850 / 0.003 / 0.153
Happiness / Mental Super Dimension (MSD)
16-24 / Female / 0.803 / 0.012 / 0.141 / 0.473 / 0.026 / 0.243
Male / 0.855 / 0.014 / 0.088 / 0.605 / 0.029 / 0.170
Total / 0.829 / 0.009 / 0.117 / 0.540 / 0.020 / 0.216
25-34 / Female / 0.791 / 0.011 / 0.153 / 0.475 / 0.019 / 0.244
Male / 0.810 / 0.011 / 0.130 / 0.526 / 0.021 / 0.229
Total / 0.800 / 0.008 / 0.142 / 0.500 / 0.014 / 0.239
35-44 / Female / 0.788 / 0.011 / 0.155 / 0.458 / 0.017 / 0.227
Male / 0.766 / 0.010 / 0.136 / 0.463 / 0.016 / 0.204
Total / 0.777 / 0.007 / 0.146 / 0.461 / 0.011 / 0.216
45-54 / Female / 0.771 / 0.009 / 0.157 / 0.444 / 0.015 / 0.228
Male / 0.777 / 0.012 / 0.163 / 0.498 / 0.019 / 0.246
Total / 0.774 / 0.007 / 0.161 / 0.471 / 0.012 / 0.240
55-64 / Female / 0.792 / 0.010 / 0.158 / 0.483 / 0.015 / 0.240
Male / 0.799 / 0.010 / 0.181 / 0.528 / 0.016 / 0.261
Total / 0.795 / 0.007 / 0.170 / 0.505 / 0.011 / 0.251
65-74 / Female / 0.828 / 0.008 / 0.147 / 0.538 / 0.014 / 0.242
Male / 0.848 / 0.007 / 0.147 / 0.576 / 0.015 / 0.276
Total / 0.838 / 0.005 / 0.148 / 0.556 / 0.010 / 0.260
Total / Male / 0.806 / 0.005 / 0.147 / 0.529 / 0.009 / 0.239
Female / 0.793 / 0.004 / 0.155 / 0.473 / 0.008 / 0.241
Total / 0.799 / 0.003 / 0.151 / 0.501 / 0.006 / 0.242
Appendix 3
Table A3.1 Mean weighted norms by gender and education
AQoL Measure / Gender / Level of Education / Mean / Std. Err. / Std. Dev.AQoL-6D / Male / High School / 0.840 / 0.010 / 0.180
TAFE/Diploma/Trade qualifications / 0.855 / 0.007 / 0.165
Graduate/postgraduate / 0.876 / 0.006 / 0.118
Female / High School / 0.814 / 0.008 / 0.192
TAFE/Diploma/Trade qualifications / 0.818 / 0.008 / 0.196
Graduate/postgraduate / 0.851 / 0.007 / 0.133
AQoL-8D / Male / High School / 0.793 / 0.012 / 0.203
TAFE/Diploma/Trade qualifications / 0.815 / 0.009 / 0.188
Graduate/postgraduate / 0.833 / 0.007 / 0.137
Female / High School / 0.770 / 0.010 / 0.219
TAFE/Diploma/Trade qualifications / 0.767 / 0.009 / 0.213
Graduate/postgraduate / 0.807 / 0.008 / 0.152
Appendix 4 Relationship between AQoL-4D, AQoL-6D and AQoL-8D
A more detailed description of the relationship between the three AQoL instruments is given in Iezzi, Richardson [3]. Statistics below were based upon 6,848 observations collected in the Multi Instrument Comparison (MIC) survey of patients and the public in 6 countries. The methods and data are described in Richardson et al. [4].
Correlation between the three instruments is given in Table A4.1 and geometric mean squares (GMS) regressions reported in Table A4.2. GMS regressions do not differ with the choice of dependent and independent variables, X and Y. They are derived from the geometric mean of coefficients derived from the OLS regressions of Y on X and X on Y.
Correlations are high. With two exceptions R2 statistics in Table A4.2 exceed the R2 from the regression of every pairwise combination of the EQ-5D-5L, SF-6D, HUI 3, 15D, QWB and AQoL-8D multi attribute utility instruments using the same data. The two exceptions are the R2 coefficients from the regression of the 15D upon the EQ-5D-5L and upon the AQoL-8D where the R2 of 0.69 equals the lowest R2 in Table A4.2. Table A4.3 indicates that, despite similarities, AQoL-6D and AQoL-8D have greater psycho-social content than AQoL-4D.
Table A4.1 Pearson correlation coefficients
AQoL / 4D / 6D / 8D / PSD (1) / MSD (2)4D / 0.83 / 0.85 / 0.77 / 0.73
6D / 0.97 / 0.76 / 0.86
8D / 0.76 / 0.92
(1) Physical super dimension of the AQoL-8D
(2) Mental (psycho-social) super dimension of the AQoL-8D
Table A4.2 GMS Regressions (n=6,848)
AQoL-6D / = 0.22+0.81 AQoL-4D / R2 = 0.69AQoL-8D / = 0.14+0.85 AQoL-4D / R2 = 0.72
AQoL-6D / -= 0.69+0.95 AQoL-8D / R2 = 0.94
Table A4.3 Regression upon AQoL-8D dimensions*(n=6,848) Beta coefficients
Dimensions / AQoL-8D / AQoL-6D / AQoL-4DPhysical
Independent living / 0.09 / 0.10 / 0.19
Pain / 0.20 / 0.19 / 0.23
Senses / 0.09 / 0.12 / 0.19
Psycho-social
Mental health / 0.20 / 0.18 / 0.05
Happiness / 0.14 / 0.08 / 0.13
Coping / 0.15 / 0.40 / 0.03
Relationships / 0.19 / 0.05 / 0.28
Self worth / 0.20 / 0.10 / 0.05
R2 (Adj) / 0.99 / 0.96 / 0.77
* All coefficients are significant at 0.00 level
References
1.Meade, A. W., & Craig, B. S. (2012). Identifying careless responses in survey data. Psychological Methods, 17(3), 437-455.
2.Trewin, D. (2001). Australian Standard Classification of Education (ASCED) (Vol. ABS Catalogue no. 1272.0). Canberra: Australian Bureau of Statistics.
3.Iezzi, A., & Richardson, J. (2016). A comparison of AQoL-4D, AQoL-6D, AQoL-7D and AQoL-8D multi attribute utility instruments, Research Paper 93. Melbourne: Centre for Health Economics, Monash University.
4.Richardson, J., Khan, M. A., Iezzi, A., & Maxwell, A. (2012). Cross-national comparison of twelve quality of life instruments: MIC Paper 1: Background, questions, instruments, Research Paper 76. Melbourne: Centre for Health Economics, Monash University [accessed 29 July 2013].