Table 9: SF-36 physical health scale Rasch analysis summary Item and Person Infit and Outfit statistics for six waves of data collection.

Wave 1 Wave 2 Wave 3Wave 4 Wave 5 Wave 6

PersonsMEAN-1.77-1.85-1.90-1.92-1.95-2.07
S.D..38.37.40.39.39.40
MAX1.54-.37.40.92-.52.40
MIN-5.13-4.11-.09-5.08-4.52-.79
Infit-MNSQ1.051.041.051.051.051.05
Infit-ZSTD-.10-.20-.10.00.00.00
Outfit-MNSQ1.001.01.98.97.96.96
Outfit-ZSTD-.30-.30-.30-.20-.20-.20
Person separation.8.8.9.9.9.9
Person reliability.4.4.4.4.4.4

ItemsMEAN.00.00.00.00.00.00
S.D..91.99.981.001.021.08
MAX1.621.581.631.641.631.79
MIN-2.22-2.49-2.46-2.45-2.43-2.49
Infit-MNSQ.95.98.95.94.94.95
Infit-ZSTD-3.00-3.00-3.10-3.40-3.40-3.30
Outfit-MNSQ.981.00.96.95.94.94
Outfit-ZSTD-3.10-3.40-3.50-3.60-3.70-3.60
Item separation71.2469.3763.2559.4152.8745.77
Item reliability1.001.001.001.001.001.00

Notes. Person or item reliability <0.8; Item separation <3.0; Person separation <2.0; values in italic for Infit or Outfit MnSq > 1.34; values underlined for Infit or Outfit MnSq < 0.64.