Research Article
Evaluating the Longitudinal Item and Category Stability of the SF-36 Full and Summary Scales Using Rasch Analysis
Table 7
SF-36 Physical health scale Rasch analysis item statistics for six waves of data collection.
| | Wave 1 | Wave 2 | Wave 3 | SF36 ITEM | MEASURE | MODEL S.E. | PTMEA CORR. | MEASURE | MODEL S.E. | PTMEA CORR. | MEASURE | MODEL S.E. | PTMEA CORR. |
| 1:Q1 | -0.84 | 0.01 | -0.21 | -0.92 | 0.01 | -0.24 | -0.91 | 0.01 | -0.18 | 3:Q3A | 1.62 | 0.02 | 0.37 | 1.58 | 0.02 | 0.44 | 1.63 | 0.02 | 0.43 | 4:Q3B | 0.02 | 0.01 | 0.59 | 0.00 | 0.01 | 0.61 | 0.13 | 0.01 | 0.60 | 5:Q3C | -0.05 | 0.01 | 0.59 | -0.08 | 0.01 | 0.60 | -0.08 | 0.01 | 0.59 | 6:Q3D | 0.52 | 0.01 | 0.60 | 0.48 | 0.01 | 0.63 | 0.55 | 0.01 | 0.62 | 7:Q3E | -0.24 | 0.01 | 0.65 | -0.27 | 0.01 | 0.67 | -0.19 | 0.01 | 0.67 | 8:Q3F | 0.21 | 0.01 | 0.57 | 0.26 | 0.01 | 0.58 | 0.33 | 0.01 | 0.54 | 9:Q3G | 0.11 | 0.01 | 0.64 | 0.15 | 0.01 | 0.66 | 0.34 | 0.01 | 0.63 | 10:Q3H | -0.34 | 0.01 | 0.67 | -0.34 | 0.01 | 0.68 | -0.19 | 0.01 | 0.67 | 11:Q3I | -0.57 | 0.01 | 0.59 | -0.62 | 0.01 | 0.59 | -0.54 | 0.01 | 0.61 | 12:Q3J | -0.74 | 0.01 | 0.43 | -0.84 | 0.01 | 0.40 | -0.80 | 0.01 | 0.40 | 13:Q4A | 0.96 | 0.01 | 0.42 | 0.95 | 0.01 | 0.41 | 1.02 | 0.02 | 0.38 | 14:Q4B | 1.32 | 0.01 | 0.42 | 1.37 | 0.02 | 0.43 | 1.46 | 0.02 | 0.39 | 15:Q4C | 1.16 | 0.01 | 0.46 | 1.17 | 0.01 | 0.50 | 1.20 | 0.02 | 0.42 | 16:Q4D | 1.20 | 0.01 | 0.44 | 1.22 | 0.02 | 0.47 | 1.28 | 0.02 | 0.42 | 21:Q7 | -0.74 | 0.01 | -0.05 | 0.99 | 0.01 | -0.19 | -0.95 | 0.01 | -0.02 | 22:Q8 | 0.36 | 0.01 | -0.18 | -0.78 | 0.01 | -0.15 | 0.04 | 0.01 | -0.14 | 33:Q11A | -2.22 | 0.01 | 0.34 | -2.49 | 0.01 | 0.34 | -2.46 | 0.01 | 0.32 | 34:Q11B | -0.07 | 0.01 | 0.02 | 0.04 | 0.01 | -0.07 | -0.09 | 0.01 | 0.02 | 35:Q11C | -1.24 | 0.01 | 0.38 | -1.42 | 0.01 | 0.38 | -1.27 | 0.01 | 0.37 | 36:Q11D | -0.42 | 0.01 | -0.09 | -0.45 | 0.01 | -0.18 | -0.50 | 0.01 | -0.08 |
| | Wave 4 | Wave 5 | Wave 6 | SF36 ITEM | MEASURE | MODEL S.E. | PTMEA CORR. | MEASURE | MODEL S.E. | PTMEA CORR. | MEASURE | MODEL S.E. | PTMEA CORR. |
| 1:Q1 | -1.10 | 0.01 | -0.14 | -1.21 | 0.01 | -0.13 | -1.32 | 0.02 | -0.06 | 3:Q3A | 1.64 | 0.02 | 0.42 | 1.63 | 0.03 | 0.42 | 1.79 | 0.04 | 0.39 | 4:Q3B | 0.26 | 0.02 | 0.60 | 0.33 | 0.02 | 0.60 | 0.47 | 0.02 | 0.57 | 5:Q3C | 0.02 | 0.01 | 0.60 | 0.05 | 0.02 | 0.58 | 0.09 | 0.02 | 0.56 | 6:Q3D | 0.59 | 0.02 | 0.62 | 0.67 | 0.02 | 0.62 | 0.77 | 0.02 | 0.59 | 7:Q3E | -0.16 | 0.01 | 0.65 | -0.09 | 0.02 | 0.65 | -0.02 | 0.02 | 0.64 | 8:Q3F | 0.32 | 0.02 | 0.57 | 0.30 | 0.02 | 0.57 | 0.34 | 0.02 | 0.53 | 9:Q3G | 0.46 | 0.02 | 0.63 | 0.62 | 0.02 | 0.61 | 0.76 | 0.02 | 0.60 | 10:Q3H | -0.07 | 0.01 | 0.66 | 0.04 | 0.02 | 0.65 | 0.17 | 0.02 | 0.63 | 11:Q3I | -0.50 | 0.01 | 0.58 | -0.43 | 0.02 | 0.58 | -0.40 | 0.02 | 0.58 | 12:Q3J | -0.76 | 0.01 | 0.42 | -0.75 | 0.01 | 0.41 | -0.79 | 0.02 | 0.39 | 13:Q4A | 1.01 | 0.02 | 0.37 | 1.03 | 0.02 | 0.34 | 0.99 | 0.03 | 0.34 | 14:Q4B | 1.47 | 0.02 | 0.38 | 1.47 | 0.03 | 0.35 | 1.45 | 0.03 | 0.33 | 15:Q4C | 1.27 | 0.02 | 0.43 | 1.29 | 0.02 | 0.40 | 1.29 | 0.03 | 0.35 | 16:Q4D | 1.31 | 0.02 | 0.41 | 1.33 | 0.02 | 0.39 | 1.32 | 0.03 | 0.36 | 21:Q7 | -1.08 | 0.01 | -0.01 | -1.17 | 0.01 | 0.01 | -1.31 | 0.02 | 0.08 | 22:Q8 | -0.19 | 0.01 | -0.13 | -0.35 | 0.01 | -0.06 | -0.53 | 0.02 | -0.02 | 33:Q11A | -2.45 | 0.01 | 0.28 | -2.43 | 0.02 | 0.26 | -2.49 | 0.02 | 0.21 | 34:Q11B | -0.20 | 0.01 | 0.01 | -0.38 | 0.02 | 0.06 | -0.53 | 0.02 | 0.11 | 35:Q11C | -1.19 | 0.01 | 0.34 | -1.08 | 0.01 | 0.33 | -1.08 | 0.02 | 0.31 | 36:Q11D | -0.68 | 0.01 | -0.09 | -0.85 | 0.01 | -0.04 | -0.98 | 0.02 | 0.02 |
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Note. MODEL S.E. = model standard error; PTMEA CORR = point measure correlation.
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