Study finds no value in depression screening
By Emma Wilkinson
Screening questionnaires for depression are not only inaccurate but completely fail to improve management of the condition, say a team of UK Cochrane researchers.
A new review concludes use of the questionnaires is practically worthless and that there is no justification for their controversial inclusion in the QOF.
Previous studies have found depression screening picks up huge number of false positives, and have questioned its benefits for control of physical illness in patients with heart disease and diabetes.
But the new study goes further – finding screening for depression only modestly increases its detection, and has no benefits for its management.
A meta-analysis of 16 studies – 12 in primary care – found the questionnaires increased recognition of depression only slightly, and not at all when given to all patients and the results made available to clinicians irrespective of baseline score.
Use of screening or case-finding increased the likelihood that any intervention would be used by 30%, but did not appear to increase the prescribing of antidepressants. Only seven of the studies provided data on outcomes of depression, and there was no evidence of any benefit for symptom scores.
The research included data on 7,500 patients and was published in the latest issue of the Canadian Association Medical Journal.
Study leader Professor Simon Gilbody, professor of psychological medicine and health services research at Hull-York Medical School, said many healthcare systems were introducing forms of depression screening despite the lack of evidence.
‘If used alone, case-finding or screening questionnaires for depression appear to have little or no impact on the detection and management of depression,' he said. ‘Recommendations to adopt screening strategies using standardised questionnaires without organisational enhancements are not justified.'
Dr Chris Manning, chief executive of Primary Care Mental Health and Education, said he was not surprised by the results. ‘If you have a GPS system and you're only picking up one satellite, you don't have much to rely on. Likewise, any screening tool on its own is not going to tell you everything.
He warned that population screening was fraught with problems and would throw up any number of false positives and negatives. ‘If you're just working on the basis of the instruments you're going to start treating people inappropriately and over medicalising them.'
But he said such tools did tend to be more useful in select groups of patients at high risk of depression.Bumpy ride for screening tools
Mar 08 - The two-question depression screening tool correctly identifies depression in only a fifth of the patients it picks up
July 07 - The Patient Health Questionnaire (PHQ-9) was found to classify twice as many patients with moderate or severe depression as another tool, the Hospital Anxiety and Depression Scale (HADS)
Feb 07 - A systematic review concludes the depression screening tools used in QOF little better than useless