Table 1.

Characteristics of the Included Studies.

AUTHOR	YEAR	COUNTRY	INTERVENTION LENGTH	FEMALES IN TOTAL SAMPLE, N (%)	SAMPLE SIZE OF CC VS UC/EUC	METHOD OF DEPRESSION DIAGNOSIS	FOLLOW-UP	OUTCOME ASSESSMENT	CC=(baseline)		UC=(baseline)
									MEAN DEPRESSION SCORE	MEAN HBA1C (%)	MEAN DEPRESSION SCORE	MEAN HBA1C (%)
Kathleen Ell	2005	USA	12-month	318(82.2)	193/194	PHQ-9≥10	6, 12, 18 month	SCL-20	1.7	9.01	1.41	9.05
de Vries McClintock	2014	USA	12-week	59(75.6)	37/41	Not clear	6, 12 week	CES-D	Not clear	7.5	Not clear	7.6
Ali	2015	India	12-month	239(59.2)	196/208	PHQ-9≥10	6, 12, 18, 24 mo	SCL-20	1.3	9.3	1.4	9
Naik	2012	USA	6-month	23 (10.2)	136/89	PHQ-9≥10	6, 12 mo	PHQ-9	15.8	9.2	16.2	9.3
Williams Jr	1999	USA	12-month	223(53.5)	205/212	structured clinical interview	6, 12 mo	SCL-20	1.67	7.3	1.72	7.3
Bogner	2010	USA	12-week	(102)56.7	92/88	a current prescription for an antidepressant	6, 12 week	PHQ-9	10.6	7.2	9.9	7
Bogner	2007	USA	12-week	49(84.5)	29/29	a current prescription for an antidepressant	2, 4, 6, 12 week	CES-D	15.6	7.3	19.7	7.3
Kathleen Ell	2005	USA	12-month	317(82)	193/194	PHQ-9≥10 and structured clinical interview	6, 12, 18, 24 month	SCL-20 and PHQ-9	Not clear	Not clear	Not clear	Not clear
Katon	2001	USA	12-month	214(65.1)	164/165	PHQ-9≥10 and SCL-20 ≥1.1	3, 6, 9, 12 month	SCL-90	1.7	8	1.6	8
Kathleen Ell	2013	USA	12-month	296(85)	178/170	PHQ-9≥10 and structured clinical interview	6, 12 month	SCL-20	1.01	8.91	1.06	8.84
Cummings	2017	USA	12-month	108(77.7)	67/72	DDS-2≥3 and/or PHQ-2 ≥ 3	6, 12 month	PHQ-12	9.7	9.88	8.8	9.35
Johnson	2010	Canada	12-month	87(55.4)	95/62	PHQ≥10	6, 12 month	PHQ-9	14.5	7.5	14.6	7.8

Abbreviations: CC, collaborative care; UC, Usual Care; eUC, enhanced Usual Care; PHQ-9, Patient Health Questionnaire–9; SCL-20, 20-item Symptom Checklist Depression Scale; CES-D, Center for Epidemiologic Studies Depression Scale; DDS-2, Diabetes Distress Scale-2; PHQ-2, Patient Health Questionnaire–2; PHQ-12, Patient Health Questionnaire–12; USA, United States.