Table 3.

Co-morbidity measures by baseline QIDS-SR₁₆

Measure					Analyses
	Baseline QIDS-SR16						Bonferroni Correction
	Mild N=81	Moderate N=238	Severe N=260	Very severe N=67	Test statistic	p- value	Mild vs. Moderate	Mild vs. Severe	Mild vs. Very severe	Moderate vs. Severe	Moderate vs. Very severe	Severe vs. Very severe
	%	%	%	%
PDSQ
Agoraphobia	1.2	8.4	12.7	22.4	χ2(3)=19.60	0.0002	0.0246	0.0027	<.0001	0.1211	0.0015	0.0455
Alcohol abuse	9.9	12.6	8.1	10.4	χ2(3)=2.75	0.4325
Bulimia	2.5	10.1	16.2	14.9	χ2(3)=12.52	0.0058	0.0305	0.0013	0.0057	0.0460	0.2660	0.8063
Drug abuse	2.5	3.8	6.2	11.9	p <0.01	0.0503
Generalized anxiety	3.7	15.5	24.6	37.3	χ2(3)=32.45	<.0001	0.0054	<.0001	<.0001	0.0119	<.0001	0.0373
Hypochondriasis	2.5	0.8	6.9	10.4	p <0.01	<.0001	0.2677	0.1792	0.0792	0.0006	0.0005	0.3330
Obsessive-compulsive	8.6	11.3	12.3	17.9	χ2(3)=3.18	0.3645
Panic disorder	2.5	6.3	11.2	28.4	χ2(3)=34.00	<.0001	0.2563	0.0176	<.0001	0.0567	<.0001	0.0004
Post-traumatic stress disorder	4.9	8.8	15.4	23.9	χ2(3)=17.04	0.0007	0.2611	0.0143	0.0008	0.0257	0.0009	0.0998
Social phobia	7.4	22.3	34.6	41.8	χ2(3)=33.21	<.0001	0.0029	<.0001	<.0001	0.0024	0.0014	0.2755
Somatoform		1.7	5.4	4.5	p <0.01	0.0244	0.5756	0.0472	0.0905	0.0270	0.1813	1.0000
Substance abuse	9.9	14.7	12.0	17.9	χ2(3)=2.86	0.4141
Number of psychiatric disorders					χ2(12)=63.54	<.0001	0.0076	<.0001	<.0001	0.0016	<.0001	0.1749
0	70.4	47.9	35.9	23.9
1	18.5	27.7	23.2	25.4
2	7.4	10.5	18.5	16.4
3	2.5	7.6	8.9	10.4
4+	1.2	6.3	13.5	23.9

Note: Chi-square for continuous measures indicates Kruskal-Wallis test.

Bold indicates significant (p <.05 for uncorrected analyses, p <.0083 for after Bonferroni correction.

QIDS-SR₁₆ categories: mild = 0–10, moderate = 11–15, severe = 16–20, very severe = 21–27.

Abbreviations: PDSQ, Psychiatric diagnostic screening questionnaire; QIDS-SR₁₆, 16 item quick inventory of depressive symptomatology – self-rated; SCQ, Self-administered comorbidity questionnaire.