Table 3: SF-36 total scale Rasch analysis summary Item and Person Infit and Outfit statistics for six waves of data collection.

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

PersonsMean-.69-.68-.72-.75-.80-.85
S.D..24.22.24.23.23.24
MAX.82.29.64.67.03.15
MIN-4.33-2.70-2.60-2.59-2.54-2.76
Infit-MNSQ1.031.021.031.041.041.03
Infit-ZSTD-.30-.40-.30-.20-.20-.10
Outfit-MNSQ1.011.011.001.00.99.99
Outfit-ZSTD-.40-.40-.30-.30-.30-.20
Person separation.8.6.7.7.7.7
Person reliability.4.2.3.3.3.3

ItemsMean.00.00.00.00.00.00
S.D.1.111.191.201.211.221.26
MAX1.941.962.052.082.092.31
MIN-2.64-2.92-2.98-3.01-2.86-2.89
Infit-MNSQ.98.99.98.98.98.99
Infit-ZSTD-2.30-2.30-2.20-1.90-1.40-.90
Outfit-MNSQ.991.00.98.98.98.98
Outfit-ZSTD-2.30-2.30-2.30-2.00-1.50-1.10
Item separation93.4089.7282.8176.4567.4358.09
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.