Comparison of a single self-assessment item with the PHQ-9 for detecting depression in general practice.
Several factors need to be considered when selecting a screening tool for depression including accuracy, level of burden for patients and for staff to administer and follow-up.



This study aimed to explore the utility of a single self-assessment item in identifying possible cases of depression in primary care by examining sensitivity and specificity with the nine-item Patient Health Questionnaire (PHQ-9) at different thresholds.



Cross-sectional survey presented on a touchscreen computer.



Adult patients attending 12 urban general practices in Australia completed a health status questionnaire (n = 1004).



Depression was assessed by the PHQ-9 and a single self-assessment item. Sensitivity, specificity, and positive and negative predictive values were calculated for the single item using a PHQ-9 score of 10 or more as the criterion value.



A total of 1004 participants (61% female, 48% aged 55 years or older) completed both the PHQ-9 and a single self-assessment item. When using a threshold of mild depression or greater, the single item had adequate specificity (76%, 95% CI: 71-80%), with 76 out of every 100 people defined as non-depressed by the PHQ-9 also identified as not depressed by the single item. Sensitivity was high (91%, 95% CI: 84-95%), with the single item identifying 91 out of every 100 true cases (as defined by the PHQ-9).



The single self-assessment item has high sensitivity and moderate specificity to identify possible cases of depression when used at a threshold of mild depression or greater.
Priority Research Centre for Health Behaviour (PRCHB), University of Newcastle, Callaghan, New South Wales, Australia, Hunter Medical Research Institute, New Lambton, New South Wales, Australia, mariko.carey@newcastle.edu.au.
Mariko
M
Carey
Priority Research Centre for Health Behaviour (PRCHB), University of Newcastle, Callaghan, New South Wales, Australia, Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
Kimberley A
KA
Jones
Priority Research Centre for Health Behaviour (PRCHB), University of Newcastle, Callaghan, New South Wales, Australia, Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
Sze Lin
SL
Yoong
National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australian Capital Territory, Australia and.
Catherine
C
D'Este
Priority Research Centre for Health Behaviour (PRCHB), University of Newcastle, Callaghan, New South Wales, Australia, Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
Allison W
AW
Boyes
Priority Research Centre for Health Behaviour (PRCHB), University of Newcastle, Callaghan, New South Wales, Australia, Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
Christine
C
Paul
Hunter Medical Research Institute, New Lambton, New South Wales, Australia, NHMRC Centre for Research Excellence in Mental Health and Substance Use, Centre for Translational Neuroscience and Mental Health, University of Newcastle, New South Wales, Australia.
Kerry J
KJ
Inder
Priority Research Centre for Health Behaviour (PRCHB), University of Newcastle, Callaghan, New South Wales, Australia, Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
Rob
R
Sanson-Fisher
Primary care; depression/mood disorder; mental health; psychiatry.; screening