Table 2.
Original | DIF adjusted | N | |||||||
HRS | ELSA | SHARE | HRS | ELSA | SHARE | HRS | ELSA | SHARE | |
Total | 1.09a,b | .81a,c | .68b,c | 1.70a,b | 1.46a,c | 1.17b,c | 10,905 | 5,437 | 13,408 |
Age | |||||||||
65–74 | 0.55b | 0.59c | 0.31b,c | 0.99a,b | 1.10a,c | 0.63b,c | 5,879 | 3,152 | 8,022 |
75–84 | 1.17a,b | 0.96a | 0.92b | 1.90a,b | 1.75a,c | 1.59b,c | 3,668 | 1,859 | 4,390 |
85+ | 3.17a,b | 1.80a,c | 2.55b,c | 4.24a,b | 2.96a,c | 3.66b,c | 1,358 | 426 | 996 |
Gender | |||||||||
Men | 0.85a,b | 0.72a,c | 0.53b,c | 1.39b | 1.30c | 0.93b,c | 4,620 | 2,423 | 6,070 |
Women | 1.26a,b | 0.89a,c | 0.80b,c | 1.93a,b | 1.60a,c | 1.36b,c | 6,285 | 30,140 | 7,338 |
Men | |||||||||
65–74 | 0.52b | 0.54c | 0.28b,c | 0.93b | 1.01c | 0.55b,c | 2,678 | 1,462 | 3,805 |
75–84 | 1.00b | 0.85 | 0.75b | 1.65b | 1.53c | 1.33b,c | 1,503 | 792 | 1,929 |
85+ | 2.37a | 1.67a | 2.07 | 3.29a | 2.67a | 2.90 | 439 | 171 | 336 |
Women | |||||||||
65–74 | 0.57b | 0.64c | 0.34b,c | 1.05b | 1.17c | 0.70b,c | 3,201 | 1,692 | 4,217 |
75–84 | 1.29a,b | 1.04a | 1.06b | 2.07b | 1.91 | 1.79b | 2,165 | 1,067 | 2,461 |
85+ | 3.55a,b | 1.89a,c | 2.80b,c | 4.69a,b | 3.16a,c | 3.99b,c | 919 | 255 | 660 |
Educationd | |||||||||
Secondary/high school or less | 1.26a,b | 0.90a,c | 0.72b,c | 1.95a,b | 1.59a,c | 1.24b,c | 7,197 | 4,070 | 11,548 |
Beyond secondary/high school | 0.74a,b | 0.49a,c | 0.38b,c | 1.22a,b | 0.96a,c | 0.73b,c | 3,705 | 843 | 1,744 |
Notes. ADL = activities of daily living; DIF = differential item functioning; ELSA = English Longitudinal Study of Aging; HRS = Health and Retirement Survey; IADL = instrumental activities of daily living; IRT = item response theory; SHARE = Survey of Health, Ageing and Retirement in Europe; Original scores = sum of 11 ADL and IADL items where difficulty was reported; DIF-adjusted IRT scores = linear transformation of DIF-adjusted IRT scores so that range = 0–11.
HRS and ELSA different at p ≤ .05.
HRS and SHARE different at p ≤ .05.
ELSA and SHARE different at p ≤ .05.
Missing cases in Education due to Don’t Know responses or inability to classify; 3 in HRS; 524 in ELSA (mostly in a “foreign education category” that could not be classified); 116 in SHARE.