TABLE 3.

Estimates of Exposure Rates, Incident Risk Ratios, Attributable Fractions, and Number Needed to Treat for Highest-Risk Predictors of Incident Major Depression in Elderly Primary Care Patients

Independent Variable	Exposure Rate	Incident Risk Ratio		Attributable Fraction		Number Needed to Treat
		Ratio	95% CI	%	95% CI
All study subjects
Caucasian race	90.11	4.23	0.57 to 31.32	74.06	−67.53 to 95.98	31
Minor or subsyndromal depression	37.44	2.86	1.33 to 6.15	41.40	11.13 to 61.36	23
Poor or fair self-rated health	11.67	1.82	0.79 to 4.20	10.91	−4.41 to 23.98	29
Physical Self-Maintenance Scale total score >0	53.00	2.86	1.19 to 6.84	51.23	9.09 to 73.84	31
Duke Social Support Index perceived social support subscale score ≤20	44.89	1.73	0.84 to 3.55	25.68	−8.41 to 49.06	48
Family Emotional Involvement and Criticism total score <7	86.87	3.57	0.83 to 15.35	67.62	−18.44 to 91.15	32
History of major or minor depression	23.18	2.47	1.12 to 5.44	18.05	0.46 to 32.53	21
Other psychiatric disordera	12.80	2.67	1.22 to 5.86	17.07	1.41 to 30.24	19
Total attributable fraction				98.95	85.71 to 99.92
Subjects with minor or subsyndromal depression
Caucasian race	90.04	2.88	0.37 to 22.01	62.15	−1.31 to 93.80	17
Poor or fair self-rated health	19.91	1.64	0.61 to 4.39	11.18	−11.09 to 28.99	20
Physical Self-Maintenance Scale total score >0	65.80	2.22	0.71 to 7.02	44.61	−26.30 to 75.70	22
Duke Social Support Index perceived social support subscale score ≤20	54.11	1.81	0.71 to 4.60	27.99	−19.92 to 58.87	21
Family Emotional Involvement and Criticism total score <7	80.09	3.05	0.68 to 13.56	60.79	−36.33 to 88.72	17
History of major or minor depression	11.69	3.26	1.13 to 9.37	16.50	−0.73 to 30.78	7
Other psychiatric disordera	17.75	2.34	0.87 to 6.32	16.38	−0.82 to 33.29	12
Total attributable fraction				96.71	47.86 to 99.79
Subjects with minor or subsyndromal depression and functional disability (Physical Self-Maintenance Scale score >0)
Caucasian race	94.12	3.05	0.39 to 23.55	63.26	−11.43 to 93.62	14
Poor or fair self-rated health	29.41	1.46	0.51 to 4.18	9.21	−14.86 to 28.24	27
Duke Social Support Index perceived social support subscale score ≤20	70.59	1.98	0.69 to 5.73	34.97	−20.57 to 64.93	16
Family Emotional Involvement and Criticism total score <7	94.12	5.76	0.74 to 44.87	77.78	−36.05 to 96.37	11
History of major or minor depression	23.53	4.73	1.37 to 16.33	18.56	2.01 to 32.30	5
Other psychiatric disordera	35.29	3.55	1.18 to 10.68	25.35	1.36 to 43.50	7
Total attributable fraction				97.54	48.75 to 99.88

^aData represent a SCID diagnosis of any current alcohol-related or anxiety disorder.