Table 3.
Factor loadings in exploratory factor analysis of the PQ-16 scores among pregnant Peruvian women (N=2059)
| Factor loadings |
||||
|---|---|---|---|---|
| Items | Unstable sense of reality | Ideas of reference/ paranoia | Sensitivity to sensory experiences | Other |
| 1. I feel uninterested in the things I used to enjoy. | 0.315 | 0.085 | −0.219 | 0.509 |
| 2. I often seem to live through events exactly as they happened before (de ja vu). | −0.027 | −0.003 | 0.159 | 0.717 |
| 3. I sometimes smell or taste things that other people can’t smell or taste. | 0.070 | 0.125 | 0.135 | 0.635 |
| 4. I often hear unusual sounds like banging, clicking, hissing, clapping or ringing in my ears. | 0.222 | 0.055 | 0.584 | 0.298 |
| 5. I have been confused at times whether something I experienced was real or imaginary. | 0.547 | −0.084 | 0.462 | 0.075 |
| 6. When I look at a person, or look at myself in a mirror, I have seen the face change right before my eyes. | 0.506 | −0.077 | 0.268 | −0.012 |
| 7. I get extremely anxious when meeting people for the first time. | 0.575 | 0.071 | −0.004 | −0.016 |
| 8. I have seen things that other people apparently can’t see. | 0.109 | 0.340 | 0.609 | 0.026 |
| 9. My thoughts are sometimes so strong that I can almost hear them. | 0.513 | 0.146 | 0.223 | 0.127 |
| 10. I sometimes see special meanings in advertisements, shop windows, or in the way things are arranged around me. | 0.137 | 0.558 | −0.351 | 0.226 |
| 11. Sometimes I have felt that I’m not in control of my own ideas or thoughts. | 0.651 | 0.208 | 0.055 | 0.076 |
| 12. Sometimes I feel suddenly distracted by distant sounds that I am not normally aware of. | 0.446 | 0.231 | 0.122 | 0.084 |
| 13. I have heard things other people can’t hear like voices of people whispering or talking. | 0.100 | 0.708 | 0.328 | −0.028 |
| 14. I often feel that others have it in for me. | 0.352 | 0.485 | 0.149 | −0.004 |
| 15. I have had the sense that some person or force is around me, even though I could not see anyone. | 0.089 | 0.733 | 0.035 | 0.124 |
| 16. I feel that parts of my body have changed in some way, or that parts of my body are working differently than before. | 0.471 | 0.150 | −0.095 | 0.154 |
| % of the variance | 0.221 | 0.084 | 0.072 | 0.063 |
•
Kaiser’s Measure of Sampling Adequacy: Overall MSA = 0.83654312
•
Bartlett’s test of sphericity: p<0.0001
•
PCA with varimax rotation
•
“The 16-item PQ consists of 9 items out of the perceptual abnormalities/hallucinations subscale, 5 items including unusual thought content/delusional ideas/paranoia, and 2 negative symptoms.” (Ising, H.K. et al., 2012. The validity of the 16-item version of the Prodromal Questionnaire (PQ-16) to screen for ultra-high risk of developing psychosis in the general help-seeking population. Schizophrenia bulletin, 38(6), pp.1288–1296.)