Table 1

Characteristics of studies included in the systematic review

Study authors (year)Country (time period)Study design (data source)Sample sizeDepression diagnosisOutcome diagnosis amputation
Black et al (2003)23USA (baseline interview 1993–1994; follow-up waves in 1995–1996, 1998–1999, 2000–2001)Prospective cohort (longitudinal data from the EPESE survey)3050 community-dwelling Mexican Americans aged ≥65 years with type 2 diabetesCESD scale (validated) and CIDI criteria (validated)Self-reported in interview, grouped ‘microvascular complications’ outcome (amputation, nephropathy, retinopathy, neuropathy)
Gendelman et al (2009)24USA (2006–2008)Cross-sectional (data from the CACTI study)1004 participants (n=458 type 1 diabetics)BDI-II scale (validated) and/or self-reported use of antidepressant medicationSelf-reported in interview
Lin et al (2010)25USA (baseline survey 2000–2002; follow-up telephone call 2005–2007)Prospective cohort (data from the PEFS study)4623 participants with type 2 diabetes (3723 included in analysis)PHQ-9 self-reported questionnaire (validated)Medical record review using ICD-9 codes, physician diagnosed. Grouped ‘microvascular outcome’ (amputation, end-stage renal disease, eye complications, foot ulcers)
Pearson et al (2014)26Australia (February–August 2012)Cross-sectional survey of patients attending podiatry clinic60 patients with type 1 or 2 diabetesPHQ-9 self-reported questionnaire (validated)Medical record review
Salmi et al (2011)27Sweden (2006), follow-up 2007–2009National register-based cohort229 956 patients prescribed antidiabetic drugsNot reported (abstract only) but most likely ICD codesNot reported (abstract only) but most likely ICD codes
Williams et al (2011)13USA (2000), follow-up until 2004Prospective cohort (Diabetes Epidemiology Registry)531 973 veterans with diabetes (type unknown)ICD-9 codesICD-9 codes
Winkley et al (2007)28UK (2001–2003), follow-up 18 monthsProspective cohort253 type 1 or 2 diabetic patients attending a podiatry clinicSCAN 2.1 diagnostic interviewRecorded by trained podiatrist
  • BDI-II, Beck Depression Inventory—version two; CACTI, Coronary Artery Calcification in Type I Diabetes Study; CESD, Center for Epidemiologic Studies Depression Scale; CIDI, Composite International Diagnostic Interview; EPESE, Established Population for the Epidemiologic Study of the Elderly Survey; ICD, International Classification of Diseases; PEFS, Pathways Epidemiologic Follow-Up Study; PHQ-9, Patient Health Questionnaire version 9; SCAN, Schedules for Clinical Assessment in Neuropsychiatry.