Table 3.
Item parameters* and standard errors for the anchor items and studied items with DIF from the depression item bank: Comparison of age groups (age 65 and over vs. age 64 and under)
| Content | Group | a | b1 | b2 | aDIF | bDIF‡ |
|---|---|---|---|---|---|---|
| I felt that I had no energy | 65+ | 1.64 (0.12) | −1.55 (0.15) | −0.20 (0.15) | <0.1 (0.999) | 8.2 (0.017) |
| ≤64 | 1.64 (0.12) | −1.14 (0.10) | −0.12 (0.09) | |||
| I felt worthless | 65+ | 3.48 (0.28) | 0.00 (0.10) | 0.77 (0.16) | 0.2 (0.655) | 8.9 (0.012) |
| ≤64 | 3.48 (0.28) | 0.27 (0.06) | 0.93 (0.07) | |||
| I felt that I had nothing to look forward to | 65+ | 3.03 (0.25) | −0.23 (0.10) | 0.46 (0.12) | 3.6 (0.058) | 17.4 (<0.001) |
| ≤64 | 3.03 (0.25) | 0.15 (0.06) | 0.80 (0.07) | |||
| I felt helpless | 65+ | 4.59 (0.89) | −0.02 (0.09) | 0.61 (0.13) | 5.9 (0.015) | 0.7 (0.705) |
| ≤64 | 3.02 (0.29) | 0.10 (0.06) | 0.85 (0.08) | |||
| I withdrew from other people | 65+ | 2.22 (0.18) | −0.27 (0.06) | 0.51 (0.07) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt that nothing could cheer me up | 65+ | 3.14 (0.27) | −0.10 (0.11) | 0.91 (0.16) | <0.01 (0.999) | 7.6 (0.022) |
| ≤64 | 3.14 (0.27) | 0.13 (0.06) | 0.82 (0.07) | |||
| I felt that other people did not understand me | 65+ | 2.21 (0.19) | −0.72 (0.06) | 0.12 (0.07) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt that I was not as good as other people | 65+ | 2.32 (0.21) | −0.12 (0.06) | 0.69 (0.08) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt like crying | 65+ | 1.80 (0.14) | −0.08 (0.14) | 1.20 (0.23) | 1.6 (0.206) | 8.6 (0.014) |
| ≤64 | 1.80 (0.14) | −0.29 (0.08) | 0.70 (0.09) | |||
| I felt sad | 65+ | 2.68 (0.22) | −0.86 (0.05) | 0.14 (0.07) | NS, no DIF | |
| ≤64 | ||||||
| I felt that I wanted to give up on everything | 65+ | 3.10 (0.26) | 0.10 (0.12) | 0.88 (0.18) | 2.0 (0.157) | 9.5 (0.009) |
| ≤64 | 3.10 (0.26) | 0.42 (0.06) | 1.04 (0.08) | |||
| I felt that I was to blame for things | 65+ | 2.34 (0.20) | −0.32 (0.06) | 0.60 (0.07) | NS, no DIF | |
| ≤64 | ||||||
| I felt like a failure | 65+ | 3.26 (0.29) | −0.08 (0.05) | 0.56 (0.06) | NS, Anchor Item | |
| ≤64 | ||||||
| I had trouble feeling close to people | 65+ | 2.54 (0.19) | −0.58 (0.11) | 0.12 (0.13) | <0.01 (0.999) | 7.1 (0.029) |
| ≤64 | 2.54 (0.19) | −0.41 (0.07) | 0.38 (0.06) | |||
| I felt disappointed in myself | 65+ | 2.64 (0.21) | −0.69 (0.05) | 0.16 (0.07) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt that I was not needed | 65+ | 2.66 (0.20) | −0.28 (0.11) | 0.54 (0.16) | 1.0 (0.317) | 8.7 (0.013) |
| ≤64 | 2.66 (0.20) | 0.01 (0.06) | 0.77 (0.08) | |||
| I felt lonely | 65+ | 2.26 (0.18) | −0.42 (0.06) | 0.38 (0.07) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt depressed | 65+ | 3.25 (0.27) | −0.44 (0.05) | 0.40 (0.06) | NS, Anchor Item | |
| ≤64 | ||||||
| I had trouble making decisions | 65+ | 2.09 (0.18) | −0.48 (0.07) | 0.61 (0.08) | NS, no DIF | |
| ≤64 | ||||||
| I felt discouraged about the future | 65+ | 2.47 (0.18) | −0.62 (0.10) | −0.11 (0.11) | 2.3 (0.129) | 9.6 (0.008) |
| ≤64 | 2.47 (0.18) | −0.59 (0.07) | −0.20 (0.07) | |||
| I found that things in my life were overwhelming | 65+ | 2.50 (0.18) | −0.35 (0.13) | 0.70 (0.15) | 2.3 (0.129) | 7.9 (0.019) |
| ≤64 | 2.50 (0.18) | −0.44 (0.07) | 0.35 (0.07) | |||
| I felt unhappy | 65+ | 3.45 (0.29) | −0.76 (0.05) | 0.17 (0.05) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt I had no reason for living | 65+ | 2.44 (0.27) | 0.85 (0.08) | 1.55 (0.12) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt hopeless | 65+ | 3.82 (0.38) | 0.13 (0.05) | 0.88 (0.06) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt ignored by people | 65+ | 2.12 (0.18) | −0.38 (0.06) | 0.56 (0.08) | NS, no DIF | |
| ≤64 | ||||||
| I felt upset for no reason | 65+ | 2.30 (0.20) | −0.02 (0.06) | 0.83 (0.08) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt that nothing was interesting | 65+ | 2.26 (0.18) | −0.25 (0.06) | 0.76 (0.08) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt pessimistic | 65+ | 2.33 (0.18) | −0.66 (0.06) | 0.24 (0.07) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt that my life was empty | 65+ | 2.85 (0.22) | −0.13 (0.11) | 0.61 (0.16) | 0.3 (0.584) | 6.4 (0.041) |
| ≤64 | 2.85 (0.22) | 0.07 (0.06) | 0.56 (0.07) | |||
| I felt guilty | 65+ | 2.04 (0.17) | −0.22 (0.07) | 0.72 (0.08) | NS, Anchor Item | |
| ≤64 | ||||||
| I felt emotionally exhausted | 65+ | 2.64 (0.21) | −0.55 (0.05) | 0.27 (0.07) | NS, Anchor Item | |
| ≤64 | ||||||
| I had trouble enjoying things that I used to enjoy | 65+ | 2.48 (0.18) | −0.80 (0.10) | 0.06 (0.12) | 2.7 (0.100) | 36.3 (<0.001) |
| 64 | 2.48 (0.18) | −0.24 (0.07) | 0.53 (0.07) | |||
*
Parameter estimates are from the final MULTILOG run
‡
DIF significant after Bonferroni adjustment is bolded; NCDIF items are italicized.