QOF driving depression drug use
By Lilian Anekwe
Patients are being systematically overdiagnosed with severe depression because of flaws in the most commonly used QOF assessment tool, new research suggests.
The Patient Health Questionnaire (PHQ-9) was found to classify twice as many patients with moderate or severe depression as a second tool, the Hospital Anxiety and Depression Scale (HADS).
Researchers warned GPs to be 'very cautious' over use of the PHQ-9, claiming it could be responsible for mass over-medicalisation of depression. Although both scales performed well at diagnosing depression, the PHQ-9 was less sensitive to the different gradations – categorising 74% of patients as moderately to severely depressed, compared with 37% using HADS.
Isobel Cameron, a research fellow at the department of mental health, University of Aberdeen, said: 'GPs should be very cautious about using the PHQ-9. If GPs are rigidly following the NICE guidelines then the implication is many patients may be being prescribed antidepressants when they should not be.'
Ms Cameron admitted it was also possible HADS was overassessing severity and said research needed to be done in the UK to test the validity of all depression diagnostic tools, and the clinical relevance of the severity cut-off bands.
The study, presented at the Society for Academic Primary Care conference in London last week, assessed 544 patients at the beginning and end of treatment to measure each tool's reliability and consistency.
Dr Simon Gilbody, senior lecturer in mental health services research at the University of York, said that although the PHQ-9 was a good instrument, GPs would need to be careful not to set cut-off points too low. The real debate, he added, was how patients were treated once diagnosed. 'GPs often don't have the resources, so the danger is that they might start to overmedicalise.'
Dr Relton Cummings, chair of Newcastle and North Tyneside LMC, said he relied more on clinical experience than PHQ-9 to diagnose depression. 'I'm not a great believer that it's a useful tool – it's a hoop to be jumped through,' he said.