330
Letters to the Editor
Hard-TYM: a pragmatic study The Test Your Memory (TYM) test is a cognitive screening instrument which patients self-administer under medical supervision (Brown et al., 2009). TYM is useful for diagnosing dementia (Hancock and Larner, 2011) and Alzheimer’s disease (AD) (Brown et al., 2009; Brown, 2013). Recently, the Hard-TYM (H-TYM) test, another patient self-administered instrument, has been developed specifically to identify patients with mild AD and amnestic mild cognitive impairment (aMCI) by testing visual and verbal recall of newly learnt material. The proof-of-concept study recruited patients with known diagnoses of aMCI/AD and normal controls. H-TYM detected 95% of cases at a cutoff of ≤13/30, with a sensitivity of 0.95 and a specificity of 0.93 (Brown et al., 2014). An independent pragmatic study was undertaken to examine the diagnostic accuracy of H-TYM in patients seen in a dedicated cognitive disorders clinic whose differential diagnosis at initial clinical assessment included MCI. Of 314 consecutive new outpatient referrals seen over 12 months (October 2013–October 2014; F: M = 158:156), 80 were diagnosed with dementia (prevalence = 25%) based on experienced clinician judgment applying widely accepted clinical diagnostic criteria for dementia (DSM-IV) and MCI (Petersen). In 38 cases (=12% of whole cohort; 16% of nondemented patients; F:M = 17:21, median age 55.5 years) H-TYM was administered because of clinical uncertainty as to whether the diagnosis was MCI or subjective memory impairment. All these patients had scored ≥24/30 on MMSE and/or ≤10/28 on the Six-Item Cognitive Impairment Test (= “normal cognition” 0–4, or “questionable impairment” 5–9; Jefferies and Gale, 2013) and were not demented. All patients completed H-TYM in around 5–10 min. H-TYM scores were not used in the final diagnostic judgment to avoid review bias. There was a low negative correlation between patient age and H-TYM scores (r = 0.37), as in the index study. There were low correlations between H-TYM scores and MMSE scores (r = 0.22) and 6CIT scores (r = 0.45, 6CIT negatively scored). At the H-TYM cutoff of ≤13/30 specified in the index paper (Brown et al., 2014), test sensitivity for diagnosis of MCI was found to be 0.67 with specificity of 0.66 (Table 1, left hand column). Revising the cutoff to
Copyright # 2014 John Wiley & Sons, Ltd.
Table 1 Diagnostic parameters for H-TYM for diagnosis of MCI at different cutoffs (with 95% confidence intervals) ≤13/30
≤15/30
0.66 (0.51–0.81) 0.67 (0.29–1.00) 0.66 (0.49–0.82) 0.33 0.27 (0.04–0.49)
0.58 (0.42–0.74) 1.00 0.50 (0.33–0.67) 0.50 0.27 (0.09–0.46)
0.91 (0.80–1.00)
1.00
0.18
0.27
1.94 (0.92–4.07) = unimportant 0.51 (0.24–1.07) = unimportant 3.82 (1.82–8.01) 0.18 (very poor)
2.00 = small
0.60 (adequate)
0.50 (adequate)
H-TYM cutoff Accuracy Sensitivity Specificity Youden index Positive predictive value Negative predictive value Predictive summary index Positive likelihood ratio Negative likelihood ratio Diagnostic odds ratio Positive clinical utility index Negative clinical utility index
0 = large ∞ 0.27 (very poor)
≤15/30 to maximize test sensitivity (1.00), specificity was 0.50 (Table 1, right hand column). H-TYM is a stringent test, which should be reserved for patients with mild cognitive impairments. In this patient cohort, H-TYM proved very sensitive for MCI when the diagnosis could not be made on initial consultation and cognitive testing (MMSE, 6CIT), although this was relevant to only a small number of patients since the clinical diagnosis of MCI was made in the majority of cases in this cohort (61/67 = 91%) without recourse to H-TYM. Cutoff revision to maximize sensitivity reduced specificity (as in the index study) and increased false positive rate (0.34 rising to 0.50). As anticipated, the results in this prospective consecutive cohort were less impressive than in the case–control paradigm of the index study. Nevertheless, these data suggest that H-TYM does have a place, perhaps particularly for the exclusion of subjective memory impairment. Conflict of interest None declared.
Int J Geriatr Psychiatry 2015; 30: 324–331
Letters to the Editor
331
References Brown JM. 2013. Test Your Memory (TYM) testing. In Cognitive screening instruments. A practical approach, Larner AJ (ed.). Springer: London; 183–199. DOI: 10.1007/978-1-4471-2452-8_9 Brown J, Pengas G, Dawson K, Brown LA, Clatworthy P. 2009. Self administered cognitive screening test (TYM) for detection of Alzheimer’s disease: cross sectional study. BMJ 338: b2030. DOI: 10.1136/bmj.b2030 Brown J, Wiggins J, Dong H, et al. 2014. The H-TYM. Evaluation of a short cognitive test to detect mild AD and amnestic MCI. Int J Geriatr Psychiatry 29: 272–280. DOI: 10.1002/gps.4005 Hancock P, Larner AJ. 2011. Test Your Memory (TYM) test: diagnostic utility in a memory clinic population. Int J Geriatr Psychiatry 26: 976–980. DOI: 10.1002/gps.2639 Jefferies K, Gale TM. 2013. 6-CIT: Six-Item Cognitive Impairment Test. In Cognitive screening instruments. A practical approach, Larner AJ (ed.). Springer: London; 209–218. DOI: 10.1007/978-1-4471-2452-8_11
Copyright # 2014 John Wiley & Sons, Ltd.
A. J. LARNER* Cognitive Function Clinic, Walton Centre for Neurology and Neurosurgery, Liverpool, UK *E-mail: [email protected] Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/gps.4249
Int J Geriatr Psychiatry 2015; 30: 324–331
Copyright of International Journal of Geriatric Psychiatry is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Letters to the Editor
Hard-TYM: a pragmatic study The Test Your Memory (TYM) test is a cognitive screening instrument which patients self-administer under medical supervision (Brown et al., 2009). TYM is useful for diagnosing dementia (Hancock and Larner, 2011) and Alzheimer’s disease (AD) (Brown et al., 2009; Brown, 2013). Recently, the Hard-TYM (H-TYM) test, another patient self-administered instrument, has been developed specifically to identify patients with mild AD and amnestic mild cognitive impairment (aMCI) by testing visual and verbal recall of newly learnt material. The proof-of-concept study recruited patients with known diagnoses of aMCI/AD and normal controls. H-TYM detected 95% of cases at a cutoff of ≤13/30, with a sensitivity of 0.95 and a specificity of 0.93 (Brown et al., 2014). An independent pragmatic study was undertaken to examine the diagnostic accuracy of H-TYM in patients seen in a dedicated cognitive disorders clinic whose differential diagnosis at initial clinical assessment included MCI. Of 314 consecutive new outpatient referrals seen over 12 months (October 2013–October 2014; F: M = 158:156), 80 were diagnosed with dementia (prevalence = 25%) based on experienced clinician judgment applying widely accepted clinical diagnostic criteria for dementia (DSM-IV) and MCI (Petersen). In 38 cases (=12% of whole cohort; 16% of nondemented patients; F:M = 17:21, median age 55.5 years) H-TYM was administered because of clinical uncertainty as to whether the diagnosis was MCI or subjective memory impairment. All these patients had scored ≥24/30 on MMSE and/or ≤10/28 on the Six-Item Cognitive Impairment Test (= “normal cognition” 0–4, or “questionable impairment” 5–9; Jefferies and Gale, 2013) and were not demented. All patients completed H-TYM in around 5–10 min. H-TYM scores were not used in the final diagnostic judgment to avoid review bias. There was a low negative correlation between patient age and H-TYM scores (r = 0.37), as in the index study. There were low correlations between H-TYM scores and MMSE scores (r = 0.22) and 6CIT scores (r = 0.45, 6CIT negatively scored). At the H-TYM cutoff of ≤13/30 specified in the index paper (Brown et al., 2014), test sensitivity for diagnosis of MCI was found to be 0.67 with specificity of 0.66 (Table 1, left hand column). Revising the cutoff to
Copyright # 2014 John Wiley & Sons, Ltd.
Table 1 Diagnostic parameters for H-TYM for diagnosis of MCI at different cutoffs (with 95% confidence intervals) ≤13/30
≤15/30
0.66 (0.51–0.81) 0.67 (0.29–1.00) 0.66 (0.49–0.82) 0.33 0.27 (0.04–0.49)
0.58 (0.42–0.74) 1.00 0.50 (0.33–0.67) 0.50 0.27 (0.09–0.46)
0.91 (0.80–1.00)
1.00
0.18
0.27
1.94 (0.92–4.07) = unimportant 0.51 (0.24–1.07) = unimportant 3.82 (1.82–8.01) 0.18 (very poor)
2.00 = small
0.60 (adequate)
0.50 (adequate)
H-TYM cutoff Accuracy Sensitivity Specificity Youden index Positive predictive value Negative predictive value Predictive summary index Positive likelihood ratio Negative likelihood ratio Diagnostic odds ratio Positive clinical utility index Negative clinical utility index
0 = large ∞ 0.27 (very poor)
≤15/30 to maximize test sensitivity (1.00), specificity was 0.50 (Table 1, right hand column). H-TYM is a stringent test, which should be reserved for patients with mild cognitive impairments. In this patient cohort, H-TYM proved very sensitive for MCI when the diagnosis could not be made on initial consultation and cognitive testing (MMSE, 6CIT), although this was relevant to only a small number of patients since the clinical diagnosis of MCI was made in the majority of cases in this cohort (61/67 = 91%) without recourse to H-TYM. Cutoff revision to maximize sensitivity reduced specificity (as in the index study) and increased false positive rate (0.34 rising to 0.50). As anticipated, the results in this prospective consecutive cohort were less impressive than in the case–control paradigm of the index study. Nevertheless, these data suggest that H-TYM does have a place, perhaps particularly for the exclusion of subjective memory impairment. Conflict of interest None declared.
Int J Geriatr Psychiatry 2015; 30: 324–331
Letters to the Editor
331
References Brown JM. 2013. Test Your Memory (TYM) testing. In Cognitive screening instruments. A practical approach, Larner AJ (ed.). Springer: London; 183–199. DOI: 10.1007/978-1-4471-2452-8_9 Brown J, Pengas G, Dawson K, Brown LA, Clatworthy P. 2009. Self administered cognitive screening test (TYM) for detection of Alzheimer’s disease: cross sectional study. BMJ 338: b2030. DOI: 10.1136/bmj.b2030 Brown J, Wiggins J, Dong H, et al. 2014. The H-TYM. Evaluation of a short cognitive test to detect mild AD and amnestic MCI. Int J Geriatr Psychiatry 29: 272–280. DOI: 10.1002/gps.4005 Hancock P, Larner AJ. 2011. Test Your Memory (TYM) test: diagnostic utility in a memory clinic population. Int J Geriatr Psychiatry 26: 976–980. DOI: 10.1002/gps.2639 Jefferies K, Gale TM. 2013. 6-CIT: Six-Item Cognitive Impairment Test. In Cognitive screening instruments. A practical approach, Larner AJ (ed.). Springer: London; 209–218. DOI: 10.1007/978-1-4471-2452-8_11
Copyright # 2014 John Wiley & Sons, Ltd.
A. J. LARNER* Cognitive Function Clinic, Walton Centre for Neurology and Neurosurgery, Liverpool, UK *E-mail: [email protected] Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/gps.4249
Int J Geriatr Psychiatry 2015; 30: 324–331
Copyright of International Journal of Geriatric Psychiatry is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
