failed to meet this criterion (Ethnibus: items 1, 2, 5, 17, 18; ONS: item 6). Fourteen of the 24 WHOQOL-OLD items failed this criterion in the Ethnibus sample only. As expected, all items correlated more highly with similar, than dissimilar, items in the scales. Cronbach’s a for the OPQOL in all three samples satisﬁed the 0.70<0.90 threshold for internal consistency: a 0.748 (Ethnibus survey), a 0.876 (ONS Omnibus survey), a 0.901 (QoL follow- up survey). The CASP-19 and the WHOQOL-OLD satisﬁed the threshold for Cronbach’s a in the ONS sample (a 0.866 and a 0.849 respectively), but neither met this in Ethnibus (a 0.553 and a 0.415 respectively) (see earlier, neither were administered in the QoL follow-up sample). The 4 week test‑retest correlations, assessed among QoL follow-up survey respondents, ranged from moderate to high (r 0.403e0.782). Lower correlations were explained by reported life changes in the intervening month, demonstrating the difﬁ- culties of test‑retest exercises in older populations. Respondents’ comments at follow-up about life changes in the last 4 weeks illustrate this: ‘About 4 days ago the plaster was taken off my left hand so now I can go on buses again ‑ my only means of regular transport apart from volunteer drivers, a few friends and taxis. Anyway it means I am free’; ‘My husband of nearly 60 years was told he has lung cancer so it has changed very much how I feel. We are trying to be as normal as possible but it’s very hard’; ‘My daughter and her young son have now left our home and acquired her own house. We miss them a lot’; ‘My husband has just come home after spending another 2 weeks in hospital (suspected heart attack)’. Validity In order to test the criterion (also known as concurrent) validity of the QoL scales, all respondents were asked to rate the ‘QoL of their lives overall’ and by area of life (‘QoL domain’), using ﬁve- point scales from ‘Very good’ to ‘Very bad’. The criterion validity of all three QoL scales was indicated by their moderate to strong, signiﬁcant correlations with global self-rated QoL: the Spear- man’s r correlations for the OPQOL by self-rated QoL overall in each sample were Ethnibus 0.347, ONS 0.602 and QoL follow-up 0.659. For the CASP, in the two cross-sectional samples, they were Ethnibus 0.273, ONS 0.577, and for the WHOQOL-OLD, in the two cross-sectional samples, they were Ethnibus 0.128 and ONS 0.466. All correlations were signiﬁcant at least at p<0.01, with the exception of WHOQOL- OLD in the Ethnibus sample which was p<0.05. (Minus signs simply reﬂect opposite coding directions). The validity of the OPQOL was further supported by signif- icant correlations between its subscales and the independent QoL domain ratings, in theoretically expected, similar direc- tions7 (eg, OPQOL health and functioning subscale correlated with self-rated health: Spearman’s r Ethnibus 0.122 (p<0.05), ONS Omnibus 0.679 (p<0.01) and QoL follow-up 0.713 (p<0.01). There were no signiﬁcant correlations with dissimilar pairs (eg, health and religion), again as expected. The CASP-19 Control and Autonomy subscales and the WHOQOL-OLD Autonomy subscale also correlated signiﬁcantly, as expected in similar directions, with self-rated independence, control over life and freedom in the ONS sample (r 0.472, p<0.01; r 0.466, p<0.01 respectively), but not in the Ethnibus J Epidemiol Community Health 2011;65:273e280. doi:10.1136/jech.2009.087668 ADL, activities of daily living; NS, not signiﬁcant; OPQOL, Older People’s Quality of Life; QOL, Quality of Life. 275 sample. The WHOQOL-OLD Sensory Abilities subscale corre- lated signiﬁcantly, again as expected, with self-rated health in the ONS (r 0.322, p<0.01), but not the Ethnibus sample. The WHOQOL-OLD Intimacy subscale correlated signiﬁcantly, also as expected, with the social relationships domain in the ONS sample (r 0.330, p<0.01), but not in the Ethnibus sample. Table 1 Multiple regression of predictors of OPQOL: QoL follow-up sample (ﬁnal model) Unstandardised B 95% CI (Two-tailed t test) Standardised b p Value Research report 4.071 to 1.203 ( 3.626) 0.0001 3.759 to 0.172 ( 2.162) 0.032 2.988 to 0.306 ( 1.606) 0.110 NS 3.194 to 0.144( 2.158) 0.032 3.660 to 0.556 ( 2.679) 0.008 4.768 to 1.749( 4.257) 0.0001 6.669 to 3.777 ( 7.124) 0.0001 2.320 to 0.957 ( 0.820) 0.413 NS 0.375 to 1.842 (2.981) 0.003 0.032 to 0.297(1.586) 0.114 NS 2.141 to 1.018 ( 0.701) 0.484 NS 0.166 to 0.642 (1.163) 0.246 NS 0.157 to 0.173 (0.095) 0.925 NS 1.279 to 5.328 (3.219) 0.002 0.250 to 1.768 (1.484) 0.140 NS 1.831 to 0.237 ( 1.520) 0.130 NS Independent predictor variables Block 1 Self-rated active ageing Block 2 QoL domain self-ratings QOL: health QoL: social relationships QoL: independence, control over life, freedom QoL: home and neighbourhood QoL: psychological and emotional well-being QoL: ﬁnancial circumstances QoL: leisure and social activities Block 3 Total number of different social activities done in last month (out of listed eight) Total number of relatives, friends, neighbours who would help with practical tasks Block 4 Self-rated health status, compared to others of same age ADL total score (sum of ability to: walk 400 yards, do heavy housework, shop/carry heavy bags, steps/stairs) Block 5 Age Sex Marital status Housing tenure Constant R2 Adjusted R2 Anova F statistic; p value 2.637 0.184 1.965 0.122 1.341 0.080 1.669 0.106 2.108 0.106 3.258 0.193 5.223 0.273 0.681 0.043 0.562 0.041 1.108 0.150 0.132 0.060 0.238 0.062 0.008 0.004 3.303 0.118 0.759 0.055 0.797 0.053 153.985 0.791 0.774 45.794; 0.0001