CardiovascularGPs Have Difficulty Separating Those With And Without Depression In Primary Care
A meta-analysis of more than 50,000 patients has shown that general practitioners (GPs) continue to have difficulty separating those with and without depression, with substantial numbers missed and misidentified. GPs looking for depression make more misidentifications (false positives of depression) than the number of depressions they correctly spot following an initial consultation but accuracy could improved by re-assessment of people suspected of having depression. These are the conclusions of an Article published Online First and in an upcoming edition of The Lancet, written by Dr Alex Mitchell, Dr Amol Vaze, and Dr Sanajay Rao of Leicester Partnership Trust and University of Leicester, Leicester, UK.
The study pooled 41 trials with a robust outcome standard of a semi-structured interview to assess depression. The researchers found that GPs were able to recognize about half of people who had clinical depression. For a typical GP trying to spot depression in an urban practice and seeing 100 cases over two days, there would be 20 true cases of depression. The GP would correctly diagnose 10 people as depressed but miss about the same number with depression. Of the remaining 80 non-depressed patients, he/she would be likely to over-diagnose 15 people (around 20%) and correctly reassure a further 65 (around 80%). In a rural setting, false positives per 100 cases would outnumber true positives by around three to one (17 vs 5). At a national level where 78% of the population see their GP over the course of a year, about 12% would be suffering from clinical depression and about half of those cases would be picked up; of the remaining 66% of the population who are not depressed and consult their GP, up to 12% would be at risk being misdiagnosed as depressed if GPs relied upon a single clinical assessment.
In asking why GPs have difficulty diagnosing depression, the authors say that since only 1 in 5 people have depression this "low" rate lends itself to higher rates of false positives. Also, more severe cases of depression are diagnosed more reliably than less severe forms. A third factor-the short appointments most people have at a GP surgery-could also contribute, since they might be inhibited from fully discussing their problems. The authors say GPs must be prepared to ask anyone in difficulty about depression. If clinicians evaluated people who might have symptoms of depression over two appointments instead of one, the authors calculate the overall diagnostic accuracy of GPs would increase to 90%.
The authors say: "Our results should not be interpreted as a criticism of GPs for failing to diagnose depression but rather a call for better understanding of the problems that non-specialists face. No data suggest that GPs do worse than other non-psychiatric medical colleagues."
They conclude: "Because one-off brief assessments only facilitate identification of about half of those with depression, we suggest that additional consultation time should be available for those likely to have depression. Repeated assessments by the GP or other professional in a collaborative model with a case manager might help to reduce diagnostic errors and improve overall quality of care."
In an accompanying Comment, Professor Peter Tyrer, Head of Department of Psychological Medicine, Imperial College London, UK, says: "If the diagnosis of depression cannot be agreed satisfactorily by the best minds in psychiatry, why should we expect the general practitioner to be a reliable assessor of the condition?"
He concludes: "It would be better to enhance the treatments available for common mental disorders in primary care. This intervention [psychosocial intervention for depression] is effective, but does cost more and will have to compete with other priorities. In the meantime, one can only hope that the new revisions of the International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders revise the nosology* of mood disorders in such a way that the current labels can be cast into oblivion."
Link to article
The Lancet