The method, which involves identifying high-risk patients with a postal questionnaire followed by targeted cognitive assessments, allowed GPs to identify cases of cognitive impairment that were not picked up by history taking.
It has been estimated that in 40-70 per cent of dementia cases, the patients' symptoms are unknown to their GP.
The study focussed on dementia diagnoses for 2,101 adults aged 75 and over who were looked after by 44 GPs. The GPs used the two-tier assessment tool and outcomes were compared with those from normal history taking.
In the first step of the screening, patients received a postal health questionnaire including a self-report version of the informant questionnaire on cognitive decline (IQCODE).
Patients with an IQCODE of 3.6 and over proceeded to stage two. Here, the patients were assessed at home with the mini mental state examination.
The screening system identified 117 patients with dementia symptoms.
But in 82 cases, GPs were unaware the patients had these symptoms.
Lead researcher Dr Hein Van Hout, from the department of general practice at the University Medical Centre, Amsterdam, said that the two-stage screening method could help to increase detection rates of dementia in primary care, which are currently extremely low.
'In the UK this method could be implemented in the annual health checks for patients aged 75 and over,' he said.
'Around four in five individuals with mild dementia are not detected, with diagnosis delays lasting up to several years not unusual. Earlier detection can instigate timely interventions. Several effective medical and psychosocial interventions are available in moderate stages of dementia for patients and their family caregivers.'
But North London GP Dr Steve Iliffe, a member of the NICE dementia guideline development group, said the two-stage method was not new and that screening for dementia was not a viable option.
'Just because we can detect more cases of dementia doesn't mean that we should,' he said.
'What do you do once you have diagnosed dementia? There are not enough resources or any effective treatment for people with dementia,' he added.
It is best to stick with the NICE dementia guidelines, which state that a diagnosis of dementia should be made only after comprehensive assessment including history taking, a review of the medication and physical examination, added Dr Iliffe.
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