Dementia patient in a screeningIntroduction
The FORGET tool
Results
Discussion
Conclusion
References

 

 

 

 

Introduction

According to Dementia UK, there were 815,827 people with dementia in the UK in 2013. If current trends continue and no action is taken, the number of people with dementia in the UK is forecast to increase to 1,142,677 by 2025 and 2,092,945 by 2051. This is an increase of 40% over the next 12 years and of 156% over the next 38 years.1

A significant ‘diagnostic gap’ for dementia, of more than a 50% exists between predicted prevalence and the actual GP registers across many regions in England, with only 46% of estimated dementia patients having a formal diagnosis locally.2 This is due to a combination of factors including late patient recognition and presentation to the GPs, delayed referrals from the GPs to specialists and long waiting times to memory services. One measure to facilitate early diagnosis of dementia is to have robust and easy to administer screening tools that can be used with reliability at the primary point of contact, which is the GP surgery and acute medical hospitals for elderly individuals.

Conventional screening tests such as the Mini- Mental State Examination and 6-CIT (Cognitive Impairment Test) are used in primary and secondary care. However, they tend to lack focus on history and progression that are crucial for evidence of progressive cognitive impairment in dementia. There is also a training issue with some of these assessments and they add time in the clinical appointment slots offered in primary care. To overcome these drawbacks it is important to develop a screening tool for dementia that can be used by healthcare providers with ease and confidence.

 

The FORGET tool

A screening tool developed to facilitate use by healthcare professionals in hospital and across the community setting will need to focus on duration of functional impairments and common symptoms of dementia.

The FORGET screening tool consists of seven- items, and takes about 5–7 minutes to administer. Each item carries a score of 1 leading to maximum score of seven (Table 1). Although the questions can be answered by carers and patients in the early stages of dementia, the tool has been tested on carers.

As the items in the screening tools are the most common issues that come up for discussion in clinical assessments, they are easy to capture in the clinic time and the items form the word FORGET, making it easy for clinicians to remember.

This pilot study of the FORGET tool involved 30 consecutive referrals each to out-patient clinics in Parklands Hospital and Basingstoke Older Peoples Mental Health Liaison Service from North Hants Hospital in Basingstoke.

Junior doctors and nurses in this study have been trained in FORGET as well as conducting clinical and cognitive assessments in patients with cognitive impairment. A consultant psychiatrist, who was blind to the FORGET score, offered a diagnosis of dementia using the ICD-10 criteria.

Demographic data including age and gender as well as MMSE score has been collected for all individuals. Sensitivity, specificity, positive predictive value, negative predictive value and odds ratio has been calculated.

 

Results

Name:
D.O.B:
Name of the carer who provides history:
Item
(Should be present at least 6 months)
Present= 1
Absent= 0
Forgetfulness  
Family/friends recognition  
Odd beliefs or Out of character behaviours  
Repetitive or reduced speech  
Grooming difficulties  
Evening confusion and sleeplessness  
Toilet awareness  
Total Score (Maximum 7)  

Of the 30 patients assessed in the memory clinic 25 received a diagnosis of dementia and of those assessed in the hospital 20 received the diagnosis. (Table 2). The average age of those diagnosed with dementia in the memory clinic was 80.64 (68–92) and in the liaison service it was 86.1 (77–103). Across both these settings, the average age of those with dementia was found to be higher than those without dementia.

Women present more with cognitive impairment and hence with dementia, which is a common finding in similar studies in dementia. Sub-types of dementia have been made using a combination of history, clinical assessment, cognitive assessment (where possible using Addenbrooke’s Cognitive Examination-Revised) and neuroimaging. Alzheimer’s disease dementia continues to remain the most common type of dementia in the elderly.

The average FORGET score of those diagnosed with dementia in the memory clinic was 2.72 and in the liaison setting it was 4.75. The average MMSE score of those diagnosed with dementia was 23.48 in the memory clinic and 11.1 in the liaison clinic. FORGET scores and MMSE scores were much lower in those diagnosed with dementia compared to those without dementia across both community and acute hospital samples.

A FORGET score of more than 1 has an odds ratio of 16 (p 0.02) for diagnosis of dementia in the community and has a sensitivity of 80% and specificity of 80%. In the liaison service, a FORGET score of more than 1 has an odds ratio of 19 (p 0.06) for a diagnosis of dementia and has a sensitivity of 100% and specificity of 30%. However, if the FORGET cut off was more than 3, then the odds ratio went up to 171 (p 0.0005) and sensitivity became 95% as the specificity increases to 90%. PPV, NPV and comparable odds ratios for MMSE are given in Tables 2 and 3.

We also looked at the value of adding MMSE to FORGET as a screening means. In a community clinic sample, the MMSE score of less than 27 and a FORGET score of more than 1 had a sensitivity of 72% and specificity of 80%. In the liaison sample, a MMSE score of less than 27 and a FORGET score of more than 3 had a sensitivity of 95% and specificity of 100%.

 

Discussion

This pilot study of FORGET as a history-based screening tool for dementia demonstrates that in a community sample, a score of more than 1 provides sensitivity, specificity of 80%, PPV of 95% and NPV of 44%. In an acute medical hospital sample, a score of more than 3 provides sensitivity of 95%, specificity of 100%, PPV of 95% and NPV of 90%.

A recent study3 reported that a MMSE cut-off score of 23 or less has a sensitivity of 69% and a specificity of 99%. In the same study PPV is reported to be less than 35% and that participating physicians consider the MMSE of little value for routine screening in unselected populations.

Another study4 reported that 6-CIT reaches a sensitivity of 0.49 and specificity of 0.92 at the 7/8 cut-off. They also suggest that the psychometric properties of 6-CIT do not suit itself to be a routine screening tool.

 

TABLE 2: DIFFERENCES BETWEEN THOSE DIAGNOSED WITH DEMENTIA AND THOSE WITHOUT DEMENTIA
  Memory Clinic Acute Medical Hospital
  Dementia No dementia Dementia No dementia
Number 25 5 20 10
Dementia sub-type Alzheimer’s= 17
Vascular= 6
DLB= 1
FTD= 1
NA Alzheimer’s= 14
Vascular= 4
DLB= 2
FTD= 0
NA
Age 80.64 (68–92) 71.2 (52–83) 86.1 (77–103) 82.2 (75–95)
Gender (Male) 10 (40%) 4 (80%) 8 (40%) 5 (50%)
FORGET score (Average) 2.72 1.2 4.75 2.1
MMSE (Average) 23.48 29 11.1 22.2

 

TABLE 3: COMPARING CUT-OFFS AND TEST PARAMETERS IN MEMORY CLINIC
Cut-offs Odds Ratio Sensitivity Specificity Positive Predictive Value Negative Predictive Value
Cut-off >1 16.00* (95% CI 1.45-17.96) p0.02 z 2.264 80% (95% CI 59.29%- 93.09%) 80% (95% CI 28.81%- 96.70%) 95.24% (95% CI 76.11%- 99.21%) 44.44% (95% CI 13.97%-78.60%)
MMSE 27 or less 29.33* (95% CI 2.40-357.86) p0.008 z 2.647
Cut-off >1 & MMSE of 27 or less 10.2857 (95% CI 0.9723- 108.8114) p 0.05 z 1.937 72% (95% CI 50.61%- 87.88%) 80% (95% CI 28.81%- 96.70%) 94.74% (95% CI 73.90%- 99.12%) 36.36% (95% CI 11.15%-69.12%)

 

In comparison to these two commonly used screening tests, FORGET does have better sensitivity across community and acute hospital samples and better specificity in the acute hospital sample. It also matches PPV with a value of 95%.

FORGET seems, therefore, to be a useful screening tool in screening for dementia in comparison with the familiar tools of cognitive screening such as MMSE or 6-CIT. The real advantage of FORGET is that it is based on history and hence would help the clinician to have a focused and structured conversation with the patient and dementia. Another distinct advantage of FORGET is that it takes less time to complete compared to these other tests. Therefore, it could be a time-saving tool for GPs in their surgeries and hospital doctors whilst completing their ward rounds. Another advantage is that unlike MMSE or 6-CIT the test asks for functional impairment and hence will help with formulating care needs for the individual with cognitive impairment.

Other advantages of this study also include paired FORGET and MMSE scores in the community and acute hospital samples and an independent assessment by a psychiatrist towards carer in understanding symptoms and the impact of providing ICD-10 based clinical diagnosis that were blind to FORGET scores. Combining FORGET with MMSE can be useful in screening and diagnosing dementia.

This study is a pilot and hence incorporated a sample size of 30 consecutive assessments in community and liaison clinics. Hence, it will need to be replicated using a bigger sample size in an acute hospital and community setting. Such bigger studies will have to explore reliability of the tool; however since this is only a structured way of collecting history, and that training is not essential, reliability may not be a problem.

 

TABLE 4: COMPARING CUT-OFFS AND TEST PARAMETERS IN ACUTE-MEDICAL HOSPITAL ASSESSMENTS
Cut-offs Odds Ratio Sensitivity Specificity Positive Predictive Value Negative Predictive Value
Cut-off >1 19.133 (95% CI 0.880- 415.906) p0.06 z 1.879 100% (95% CI 83.16%- 100%) 30% (95% CI 6.67%- 65.25%) 74.07% (95% CI 53.72%- 88.89%) 100% (95% CI 29.24%- 100.00%)
Cut-off >3 171* (95% CI 9.569- 3055.681) p0.0005 z 3.49 95% (95% CI 75.13% to 99.87%) 90% (95% CI 55.50% to 99.75%) 95% (95% CI 75.13% to 99.87%) 90% (95% CI 55.50% to 99.75%)
MMSE 27 or less 19.133 (95% CI 0.88-415.90) p0.060 z 1.879
Cut-off >3 & MMSE of 27 or less 273* (95% CI 10.197- 7309.229) p 0.0008 z 3.344 95% (95% CI 75.13% to 99.87%) 100% (95% CI 69.15% to 100.00%) 100% (95% CI 82.35% to 100.00%) 90.91% (95% CI 58.72% to 99.77%)

 

Conclusion

There is an urgent need to make screening processes for dementia easier, less time-consuming and sensitive so that it can be used by healthcare professionals in primary care and acute medical hospitals. This is crucial in early diagnosis of dementia; hence, promoting opportunities for an individual with dementia to access appropriate pharmacological and non-pharmacological treatments as well as to make advance directives regarding health and well-being.

This pilot study of FORGET, a history-based tool for screening dementia in the community and acute medical hospital, showed a cut-off score of more than 1 in the former setting and more than 3 in the latter setting has good sensitivity, specificity as well as positive-predictive value.

The values are comparable to cognitive assessment screening tools. In addition, FORGET comes with distinct advantages of being easy to administer, less time-consuming and gives clinician perspective on functional impairment from the cognitive problem. Hence, FORGET could be used in screening for dementia in elderly patients presenting with symptoms of cognitive impairment in primary care and acute medical hospital settings.

Acknowledgements: Anthea Godleman, Memory Clinic Nurse; Michelle Porter and Liz Nikiperowciz, Liaison Nurses; Dr Ruth Nesbit FY2 trainee

 

Dr Vellingiri Raja Badrakalimuthu, Consultant Old Age & Liaison Psychiatrist, Parklands Hospital, Basingstoke

Conflict of interests: none declared

 


References

1. Prince M, Knapp M, Guerchet M, et al. Dementia UK Update. Alzheimer’s Society, 2014. https://www.alzheimers.org.uk/download/downloads/id/2323/dementia_uk_update.pdf (accessed 27/07/17)

2. Mapping the Dementia Gap. Alzheimer’s Society, 2012

3. Tangalos GE, Smith GE, Ivnik RJ, et al. The mini-mental state examination in general practice: Clinical utility and acceptance. Mayo Clinical Proceedings 1996; 71: 829–37

4. Hessler J, Bronner M, Etgen T, et al. Suitability of 6-CIT as a screening test for dementia in primary patients. Aging & Mental Health 2014: 18; 515–20