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. Author manuscript; available in PMC: 2011 Mar 28.
Published in final edited form as: Arch Gen Psychiatry. 2008 Jan;65(1):28–37. doi: 10.1001/archgenpsychiatry.2007.3

Table 4.

Prediction Statistics for 5 Uniquely Associated Predictors and Their Combinations

Predictora No. of Patients χ2 Testb P Value Base Rate Hazard Ratio PPP Sensitivity Specificity
1. Genetic risk with functional decline 291 17.76 <.001 48 1.96 52 66 59
2. Unusual thought content (>3) 291 9.43 .002 43 1.98 48 56 62
3. Suspicion/paranoia (>2) 291 7.59 .006 32 2.12 43 79 37
4. Social functioning (<7) 290 4.99 .03 36 1.79 46 80 43
5. Any substance abuse 270 8.85 .003 20 2.08 43 29 83
1 and 2c 291 23.88 <.001 21 3.08 69 38 85
1 and 3c 291 23.05 <.001 36 2.93 57 56 72
1 and 4c 290 26.39 <.001 33 3.14 61 55 75
1 and 5c 270 9.97 .002 10 2.64 41 18 93
2 and 3c 291 15.35 <.001 30 2.39 52 45 76
2 and 4c 290 10.92 .001 31 2.09 51 44 74
2 and 5 270 7.03 .008 9 2.31 52 17 93
3 and 4c 290 19.48 <.001 45 2.83 53 67 63
3 and 5 270 8.18 .004 13 2.29 41 21 90
4 and 5 270 7.26 .007 11 2.23 42 19 91
1, 2, and 3c 291 29.27 <.001 18 3.58 74 34 89
1, 2, and 4c 290 25.42 <.001 16 3.41 81 30 90
1, 2, and 5 270 9.11 .003 4 3.33 53 10 97
1, 3, and 4c 290 30.77 <.001 26 3.43 67 48 82
1, 3, and 5c 270 14.05 <.001 7 3.44 51 15 96
1, 4, and 5c 270 14.03 <.001 19 3.44 51 15 96
2, 3, and 4c 290 19.19 <.001 22 2.72 58 38 84
2, 3, and 5c 270 9.85 .002 6 3.26 60 11 96
2, 4, and 5c 270 13.88 <.001 6 3.82 62 13 97
3, 4, and 5 270 7.36 .007 9 2.44 46 15 93
1, 2, 3, and 4c 290 29.18 <.001 13 3.84 81 28 92
1, 2, 3, and 5c 270 15.71 <.001 3 5.53 78 8 98
1, 2, 4, and 5c 270 17.11 <.001 4 5.23 67 10 98
1, 3, 4, and 5c 270 11.72 <.001 6 3.41 55 13 96
2, 3, 4, and 5c 270 12.41 <.001 4 4.12 71 10 97
1, 2, 3, 4, and 5c 270 15.71 <.001 3 5.53 79 8 98

Abbreviation: PPP, positive predictive power.

a

Parenthetical numbers represent the value of the scale exceeded by people who were counted as positive for that indicator.

b

Significant at a Bonferroni-corrected α of P<.002 (.05/26).

c

Prediction statistics reflect cumulative conversation status at the final follow-up as generated by the Lifetest procedure.43 The false-positive rate for each predictor is 1-specificity, and the false-negative rate is 1-sensitivity.