Table 1.
Descriptive characteristics of algorithm studies13
| Study | Sample characteristics | Sample size and % depressed | PHQ-9 characteristics | Diagnostic standard | a) COI declaration b) Funding c) Relationship with original developers |
| (country, setting, age, sex) | |||||
| Diez-Quevedo et al22 | Country: Spain Setting: medical and surgical tertiary hospitals Age (years): M=43 (SD=14.2) Female: 45.6% |
n=1003 Depressed: 8.2% |
Administration: self-report Language: Spanish |
DSM-III-R SCID |
a) No COI declaration b) Funding acknowledged (academic institutions) c) Not acknowledged |
| Gräfe et al23 | Country: Germany Setting: psychosomatic walk-in clinics and family practices Age (years): male=41.9 (SD=13.8) Female: 67.8% |
n=528 Depressed: 29.2% psychosomatic patients; 6.16% medical patients |
Language: German Administration: self-report |
DSM-IV SCID |
a) No COI declaration b) Acknowledged funding from Pfizer c) Not acknowledged |
| Lowe et al24 | Country: Germany Setting: outpatient clinics and family practices Age (years): male=41.7 (SD=13.8) Female: 67.1% |
n=501 Depressed: 13.2% |
Administration: self-report Language: German |
DSM–IV SCID |
a) COI declaration ‘This study was supported by unrestricted restricted grants from Pfizer Germany and from the medical faculty of the University of Heidelberg Germany, and there are no COI’. b) Acknowledged funding from Pfizer and academic institution c) Not acknowledged |
| Muramatsu et al27 | Country: Japan Setting: primary care and general hospital Age (years): male=43.3 (SD=16.4) Female: 59.5% |
n=131 Depressed: 28.2% |
Administration: self-report Language: Japanese |
DSM–IV MINI |
a) No COI declaration b) Acknowledged funding from Pfizer c) Acknowledged one of the developers of the PHQ-9: ‘The authors acknowledge Dr RL Spitzer’ |
| Navinés et al28 | Country: Spain Setting: general hospital (patients with chronic HCV) Age (years): male=43.4 (SD=10.2) Female: 28.6% |
n=500 Depressed: 6.4% |
Administration: self-report Language: Spanish |
DSM–IV SCID |
a) All authors declared that they had no COI. b) Role of funding source declared c) Not acknowledged |
| Spitzer et al25 | Country: USA Setting: primary care Age (years): male=46 (SD=17.2) Female: 66% |
n=3000 (585 received SCID) Depressed: 10% |
Administration: self-report Language: English |
DSM-III-R SCID |
a) No COI declaration b) Acknowledged funding from Pfizer. ‘Drs Spitzer and Williams receive honoraria and consulting money from Pfizer, which has supported this work’. c) N/A |
| Thekkumpurath et al26 | Country: UK Setting: hospital (cancer patients) Age (years): male=61 Female: 63% |
n=782 Depressed: 6.3% (of the whole sample) |
Administration: not stated Language: English |
DSM-IV SCID |
a) COI declaration: ‘Supported by Cancer Research UK’ b) As in a) c) Not acknowledged |
| Ayalon et al43 | Country: Israel Age (years): male=75 (SD=8.1) Female: 40.5% |
n=153 Depressed: 3.9% |
Administration: researcher administered Language: Hebrew |
DSM-IV SCID |
a) COI declaration: ‘The project was funded by an Investigator’s Initiated Research Grant from Lundbeck International given to Dr Liat Ayalon. Lundbeck International had no other involvement in the project concept of design or in this paper. Per Bech has occasionally over the past 3 years until August 2008 received funding from and has been speaker or member of advisory boards for pharmaceutical companies with an interest in the drug treatment of affective disorders (AstraZeneca, Lilly, H Lundbeck A/S, Lundbeck Foundation and Organon)'. b) Acknowledged funding from Lundbeck International |
| Eack et al29 | Country: USA Setting: community mental health centres for children Age (years): male=39.20 (SD 9.63) Female: 100% |
n=50 Depressed: 28% |
Administration: self-report Language: English |
DSM-IV SCID |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Fann et al30 | Country: USA Setting: trauma hospital (inpatients with traumatic brain injury) Age (years): male=42 (SD=17.9) Female: 29.1% |
n=135 Depressed: 16.3% |
Administration: telephone-administered Language: English |
DSM-IV SCID |
a) No COI declaration b) Funding acknowledged (academic institutions) |
| Gelaye et al31 | Country: Ethiopia Setting: general hospital Age (years): 34.9 (SD=11.6) Female: 63.1% |
n=363 Depressed: 12.6% |
Administration: researcher-administered Language: Amharic |
DSM-IV SCAN |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Gjerdingen et al48 | Country: USA Setting: community Age (years): male=29.3 Female: 100% |
n=438 Depressed: 4.6% |
Administration: telephone or self-report Language: English |
DSM-IV SCID |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Henkel et al44 | Country: Germany Setting: primary care Age (years): not reported Female: 74% |
n=448 Depressed: 10% |
Administration: self-report Language: German |
DSM-IV CIDI |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Hyphantis et al32 | Country: Greece Setting: hospital – rheumatology patients Age (years): male=54.2 (SD=13.5) Female: 74% |
n=213 Depressed: 32.4% |
Administration: researcher administered Language: Greek |
DSM-IV MINI |
a) No COI declaration b) No funding acknowledgement |
| Inagaki et al33 | Country: Japan Setting: general hospital Age whole sample (years): male=73.5 (SD=12.3) Female: 59.3% |
n=104 out of 511 received MINI Depressed: 7.4% |
Administration: researcher administered Language: Japanese |
DSM-IV MINI |
a) COI declaration: ‘The authors declare that they have no competing interests’. b) Funding acknowledged (academic/health research institutions) |
| Khamseh et al34 | Country: Iran Setting: diabetes clinic Age (years): male=56.17 (SD=9.60) Female: 51.9% |
n=185 Depressed: 43.2% |
Administration:self report Language: Persian |
DSM-IV SCID |
a) COI declaration: the authors declared no competing interests b) Funding acknowledged (academic/health research institutions) |
| Lamers et al45 | Country: The Netherlands Setting: primary care (elderly) Age (years): male=71.4 (SD=6.90) Female: 48.2% |
n=713 Depressed: 10.7% |
Administration:self report Language: Dutch |
DSM-IV MINI |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Lotrakul et al46 | Country: Thailand Setting: primary care Age (years): male=45.0 (SD=14.30) Female: 73.7% |
n=279 Depressed: 6.8% |
Administration:self report Language: Thai |
DSM-IV MINI |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Persoons et al35 | Country: Belgium Setting: hospital (otolaryngology patients) Age (years): male=48.2 (SD=12.9) Female: 65.6% |
n=268 (97 received MINI) Depressed: 16.5% |
Administration: self-report Language: Dutch |
DSM-IV MINI |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) and Pfizer Belgium |
| Picardi et al36 | Country: Italy Setting: hospital (dermatology inpatients) Age (years): male=37.5 Female: 56% |
n=141 Depressed: 8.5% |
Administration: self-report Language: Italian |
DSM-IV SCID |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) Acknowledged Pfizer Italia SRL for providing the Italian version of the PHQ-9 and for permission to use it. |
| Stafford et al37 | Country: Australia Setting: hospital (cardiology patients) Age (years): male=64.1 (SD=10.3) Female: 66% |
n=193 Depressed: 18% |
Administration: self-report Language: English |
DSM-IV MINI |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Thombs et al38 | Country: USA Setting: hospital (outpatients with coronary heart disease) Age (years): male=67 (SD=11) Female: 18% |
n=1024 Depressed: 22% |
Administration: not stated Language: English |
DSM C-DIS |
a) COI declaration ‘None disclosed’ b) Funding acknowledged (academic/health research institutions) |
| Thompson et al39 | Country: USA Setting: patients with Parkinson’s disease Age (years): 72.5 (SD=9.6) Female: 42% |
n=214 Depressed: 14% |
Administration:self administered Language: English |
DSM-IV SCID |
a) No COI declaration b) Funding acknowledged (academic/health research institutions) |
| Turner et al40 | Country: Australia Setting: stroke patients Age (years): 66.7 (SD=13.1) Female: 47.2% |
n=72 Depressed: 18% |
Administration:self administered Language: English |
DSM-IV SCID |
a) COI declaration: disclosures ‘none’. b) Funding acknowledged (academic/health research institutions) |
| van Steenbergen-Weijenburg et al41 | Country: The Netherlands Setting: patients with diabetes Age (years): male=61.8 (SD=13.6) Female: 48.7% |
n=197 Depressed: 18.8% |
Administration: self administered Language: Dutch |
DSM-IV SCID |
a) COI declaration: ‘The authors declare that they have no competing interests’. b) Funding acknowledged (academic/health research institutions)—‘this had no influence on the content of this article’. |
| Zuitthoff et al47 | Country: The Netherlands Setting: primary care Age (years): male=51 (SD=16.7) Female: 63% |
n=1338 Depressed: 13% |
Administration: self-report Language: Dutch |
DSM-IV CIDI |
a) COI declaration ‘The authors declare that they have no competing interests’. b) Funding acknowledged (academic/health research institutions) |
CIDI, Composite International Diagnostic Interview,CIS-R, Clinical Interview Schedule;COI, conflict of interest; DSM, Diagnostic and Statistical Manual of Mental Disorders; MINI, Mini-International Neuropsychiatric Interview; N/A, not available; SCAN, Schedules for Clinical Assessments in Neuropsychiatry; SCID, Structured Clinical Interview for DSM Disorders.