QOF depression tool causing over-diagnosis
By Georgie Hobbs
GPs using a ‘blunt' QOF assessment tool for depression may be dramatically over-diagnosing patients, with fears that large numbers of patients are being inappropriately treated with drugs.
Researchers are calling for a review of QOF guidance after finding that diagnostic rates varied dramatically depending on the assessment tool used.
The most commonly used NICE-backed tool to diagnose depression, the Patient Health Questionnaire (PHQ-9), classified twice as many patients with moderate or severe depression as a second tool, the Hospital Anxiety and Depression Scale (HADS).
In the study, both tools were used on the same 544 patients, with PHQ-9 diagnosing 74% of patients as moderately to severely depressed, compared with 37% using HADS.
The University of Aberdeen researchers warned that if GPs who used the PHQ-9 strictly adhered to the NICE stepped-care model, three quarters of depressed patients would be offered an antidepressant.
Half would be offered one if tested via HADS.
Ms Isobel Cameron, who led the research – published in January's British Journal of General Practice - said GPs should ‘exercise caution' in interpreting the test scores.
‘The measures endorsed by the QOF may well have a place but we need to find out more about how well they categorise the severity of depression. At the moment we don't know whether both or one of them is getting this wrong.'
Ms Campbell called the huge disparity in results ‘disappointing' while GPs said it was ‘worrying' - particularly because GPs are incentivised to use PHQ-9 since it is free.
Dr Chris Manning, chief executive of Primary Care Mental Health and Education, called the tools ‘blunt' and warned ‘Often GPs don't act on the findings because they don't know what to do next. The QOF has unskilled a lot of people - they seem to be forgetting their holistic skills.'
But Dr Peter Stott, a GP in Tadworth, said that no matter what tool was used, there was not enough evidence base for QOF inclusion to treat the majority of patients.
‘By and large we use the depression indicators within a population with chronic illness
Anti-depressants or cognitive treatment have never been proven to work with patients with diabetes, heart disease and other chronic illnesses. No matter what test is used, what's the point if you can't treat it?'Choosing a depression toolChoosing a depression tool Choosing a depression tool
Three depression severity measures are endorsed in QOF
Patient Health Questionnaire (PHQ-9)
• Free to download
• Nine patient-reported questions
• Take around three minutes
• Uses DSM IV criteria to categorise severity as minimal, mild, moderate, moderately severe and severe
Hospital Anxiety and Depression Scale (HADS-D)
• Costs £60 for manual and recording forms
• Seven patient-reported questions
• Takes around five minutes
• Categorises depression as normal, mild, moderate and severe
Beck Depression Inventory II (BDI-II)
• Costs $140 (£70) for manual and recording forms
• 21 patient-reported items
• Takes around five minutes
• Uses DSM-IV criteria to categorise severity as minimal, mild, moderate and severe
This study compared PHQ-9 and HADS-D and found:
• Both scales accurately measured changes in severity
• Both reliably identified depressed individuals
• PHQ-9 identified 74% of 544 patients as needing antidepressants compared to 37% using HADS