Table 1. Data extraction and outcomes of the four included studies.
| Authors (publication year) | Number of patients | Age | Gender, female (%) | Depression assessment 1) Baseline 2) Follow-up | Illness assessment | Outcome measures | Results |
| Wells, Rogers, Burnam & Camp (1993) | 554 total (3.8% SI, 96.2% NSI) | - | 73.8% (IDDM) 72.8% (non-IDDM) | 1) Eight- item depression symptom scale, DSM III criteria 2) Course of depression interview over the phone, based on DIS | Screening and structured somatic history interview | Percentage of patients with more than two depressive spells during follow -up 9.9 years | 1 year: SI: 14.9% NSI: 29.3% 2 year: SI: 36.0% NSI: 27.8% |
| Gerrits, van Oppen, van Marwijk, van der Horst & Penninx (2013) | 715 total (44.5% SI 55.5% NSI) | 42.1a | 66% | 1)CIDI, DSM IV 2) CIDI, DSM IV and Life Chart Inventory | Self-report | Percentage of patients with remission with recurrence of symptoms (at least three months symptom-free interval) | 2 year: SI: 6.0% NSI: 8.0% |
| Kovacs, Goldston, Obrosky & Drash (1997) | 54 total (44.4% SI, 55.6% NSI) | 11.2a | 61.9% | 1) ISCA, DSM-III 2) ISCA, DSM-III | Diagnoses at hospital | Recurrence rates: cumulative proportion of developing a new episode of depression after recovery | 1 year: SI: 26% NSI: 22% 2 year: SI:30% NSI: 32% 6.5 year: SI: 47% NSI: 47% |
| Hardeveld, Spijker, De Graaf Nolen & Beekman, 2012 | 687 total (48.2% SI, 51.8% NSI) | 40.7b | 68.0% | 1) CIDI, DSM-III-R 2) CIDI, DSM-III-R retrospectively and prospectively at T1 or T2 | Self-report, list of 31 mostly chronic somatic conditions | MDE recurrence between baseline and follow-up (one-or three years) for patients in partial or complete remission for at least six months | SI: 21.1% NSI: 18.3% |
Note, SI = Somatically Ill; NSI = Non-Somatically Ill; a = mean age; b = median age; IDDM = Insulin-Dependent Diabetes Mellitus; DSM III/III-R/IV criteria = Diagnostic and Statistical Manual of Mental Disorders, third edition, third edition revised; fourth edition; DIS = Diagnostic Interview Schedule; CIDI = Composite International Diagnostic Interview; ISCA = Interview schedule for children and adolescents; MDE = Major Depressive Episode.