Table 2 Results of Rasch analyses
From: Measuring engagement in deliberate self-harm behaviours: psychometric evaluation of six scales
Analysis | Overall model fit | Item fit residual mean (SD) | Person fit residual mean (SD) | % significant t-tests | Coefficient Alpha (Grading) | Person locations |
|---|---|---|---|---|---|---|
SIQTR-5 | Â | Â | Â | Â | Â | Â |
Initial fit | χ 2 = 6.639 (d f= 5), p = .249 | -0.786 (0.922) | -0.136 (0.548) | na | 0.705 | M = -1.238 |
| Â | Â | Â | Â | Â | Moderate | SD = 1.131 |
Final fit | χ 2 = 7.320 (d f= 6), p = .292 | -0.503 (0.928) | -0.069 (0.583) | na | na | M = -1.324 |
| Â | Â | Â | Â | Â | Â | SD = 1.161 |
SITBI-11 | Â | Â | Â | Â | Â | Â |
Initial fit | χ 2 = 52.463 (d f= 22), p = .0003 | -0.271 (1.384) | -0.186 (0.649) | 0.42% | 0.716 | M = -1.662 |
| Â | Â | Â | Â | Â | Fair | SD = 1.295 |
Final fit | χ 2 = 46.978 (d f= 26), p = .007 | -0.254 (1.162) | -0.202 (0.649) | na | na | M = -1.629 |
| Â | Â | Â | Â | Â | Â | SD = 1.325 |
DSHI-16 | Â | Â | Â | Â | Â | Â |
Initial fit | χ 2 = 33.957 (d f= 32), p = .373 | -0.278 (1.165) | -0.185 (0.351) | 1.69% | 0.783 | M = -3.117 |
| Â | Â | Â | Â | Â | Fair | SD = 1.159 |
Final fit | χ 2 = 30.790 (d f= 24), p = .160 | -0.127(1.209) | -0.254 (0.560) | na | na | M = -2.495 |
| Â | Â | Â | Â | Â | Â | SD = 1.136 |
ISAS-12 | Â | Â | Â | Â | Â | Â |
Initial fit | χ 2 = 38.299 (d f= 24), p = .032 | -0.278 (0.962) | -0.123 (0.713) | 1.81% | 0.826 | M = -1.872 |
| Â | Â | Â | Â | Â | Fair | SD = 1.358 |
Final fit | χ 2 = 23.441 (d f= 18), p = .174 | -0.171 (0.883) | -0.164 (0.700) | na | na | M = -1.802 |
| Â | Â | Â | Â | Â | Â | SD = 1.185 |
SHIF-16 | Â | Â | Â | Â | Â | Â |
Initial fit | χ 2 = 150.982 (d f= 64), p = .000 | -0.731(1.951) | -0.210 (0.454) | 1.6% | 0.794 | M = -2.484 |
Fair | SD = 1.195 | |||||
Final fit | χ 2 = 70.304 (d f= 46), p = .012 | -0.708 (1.174) | -0.290 (0.676) | na | na | M = -1.828 |
SD = 1.012 | ||||||
SHI-22 | Â | Â | Â | Â | Â | Â |
Initial fit | χ 2 = 289.355 (d f= 154), p = .000 | -0.537 (1.740) | -0.179 (0.712) | 5.50% (3.7-7.3) | 0.814 | M = -2.051 |
Fair | SD = 1.280 | |||||
Final fit | χ 2 = 201.992 (df =153), p = .005 | -0.460 (1.220) | -0.215 (0.764) | na | na | M = -1.944 |
SD = 1.201 | ||||||
Ideal Values | Probabilities greater than Bonferroni adjusted p values (i.e., 0.05 divided by the number of significance tests) | Mean = 0.0 | Mean = 0.0 | Less than 5% | Fair or bettera | M = 0.0 |
| Â | Â | (SD = 1.0) | (SD = 1.0) | Â | Â | Â |