Devanand 2007.
| Study characteristics | |||
| Patient sampling |
Primary objectives: to evaluate the utility of MRI hippocampal and entorhinal cortex atrophy in predicting conversion from MCI to AD Study population: participants with MCI Selection criteria: the inclusion/exclusion criteria aimed at enrolling a broad sample of cognitively impaired outpatients who presented with memory complaints and were found to have cognitive impairment without dementia based on comprehensive evaluation, but without a specific cause for the cognitive impairment. Exclusion criteria: diagnosis of dementia, schizophrenia, current major affective disorder, alcohol or substance dependence, history of stroke, cortical stroke or infarct 2 cm in diameter based on MRI, cognitive impairment entirely caused by medications, or other major neurologic illness, e.g. Parkinson disease Study design: prospective longitudinal |
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| Patient characteristics and setting |
Clinical presentation: mild cognitive impairment (MCI); subtypes definition according to the criteria of Petersen 1999 Age mean (SD): MCI who progressed to AD: 72 ± 7 years; MCI non‐converters to AD: 65 ± 10 years Gender (% men): MCI who progressed to AD: 43.2%; MCI non‐converters to AD: 44.4% Education years mean (SD): MCI who progressed to AD: 14.1 ± 4.5; MCI non‐converters to AD: 15.6 ± 4 ApoE4 carriers (%): MCI who progressed to AD: 32%; MCI non‐converters to AD: 20% Neuropsychological tests: employed; MMSE mean (SD): MCI who progressed to AD: 26 ± 2; MCI non‐converters to AD: 28 ± 2 Clinical stroke excluded: yes Co‐morbidities: not reported Number enrolled: 141 Number available for analysis: 139 for estimation of the hippocampal volume, 138 for estimation of the entorhinal cortex volume Setting: tertiary university hospitals; the Memory Disorders Center at New York State Psychiatric Institute and Columbia‐Presbyterian Medical Center. The majority (52%) were physician referred, 25% were self‐referred, and 23% were referred by family or friends or other sources Country: USA Period of study: not reported Language: English |
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| Index tests |
Index test: MRI manual method for estimation of hippocampal and entorhinal cortex volumes Manufacturer: GE Tesla strength: 1.5 Assessment methods: both the hippocampal and the entorhinal cortex volumes were manually segmented respectively according to Bobinski 2000 and Killiany 2002. Description of positive cases definition by index test as reported: not specified Examiners: a single trained rater (G.P.) evaluated all scans on a Sun UltraSPARC workstation blind to all clinical information, using a dedicated software package (MIDAS) for image segmentation and coregistration Interobserver variability: the single MRI rater was trained with expert raters and showed high interrater reliability on 10 scans (sum of left and right volumes): hippocampal volume ICC 0.90, parahippocampal gyrus volume ICC 0.96, and entorhinal cortex volume ICC 0.92 |
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| Target condition and reference standard(s) |
Target condition: AD and dementia Prevalence of AD in the sample: 35/139 (25% of cases included in the analysis) Stable MCI or converted to other dementia: 104 (75%); 102 stable MCI, 1 MCI converted to corticobasal degeneration, 1 MCI converted to amyotrophic lateral sclerosis with frontal lobe deficits Reference standard: NINCDS‐ADRDA (McKhann 1984) and DSM‐IV (American Psichiatric Association 2000) A consensus diagnosis was made between 2 expert clinical raters who remained blind to data from previous visits Mean clinical follow‐up: 3 years |
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| Flow and timing | Withdrawals and losses to follow‐up: 1 participant was excluded for head motion during MRI acquisition. Within 6 months of presentation, 2 participants with MCI were diagnosed with other neurologic disorders (corticobasal degeneration, and amyotrophic lateral sclerosis presenting with frontal lobe deficits) and were excluded Uninterpretable MRI results have not been reported | ||
| Comparative | |||
| Key conclusions by the authors | In logistic regression analyses in the 3‐year follow‐up sample, entorhinal cortex and hippocampal volume each showed moderately strong diagnostic accuracy. The combined effects of hippocampal and entorhinal cortex volumes further improved test accuracy | ||
| Conflict of interests | Study authors reported no conflicts of interest | ||
| Notes |
Source of funding: supported in part by grants AG17761, AG12101, MH55735, MH35636, MH55646, P50 AG08702, and P30 AG08051 from the NIA and the National Institute of Mental Health 2 x 2 table: data to complete 2 x 2 table provided by the study authors |
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| Methodological quality | |||
| Item | Authors' judgement | Risk of bias | Applicability concerns |
| DOMAIN 1: Patient Selection | |||
| Was a consecutive or random sample of patients enrolled? | No | ||
| Was a case‐control design avoided? | Yes | ||
| Did the study avoid inappropriate exclusions? | No | ||
| High | Low | ||
| DOMAIN 2: Index Test All tests | |||
| Were the index test results interpreted without knowledge of the results of the reference standard? | Yes | ||
| Did the study provide a clear pre‐specified definition of what was considered to be a "positive" result of the index test? | No | ||
| Was the index test performed by a single operator or interpreted by consensus in a joint session? | Yes | ||
| High | Low | ||
| DOMAIN 3: Reference Standard | |||
| Is the reference standards likely to correctly classify the target condition? | Yes | ||
| Were the reference standard results interpreted without knowledge of the results of the index tests? | Yes | ||
| Low | Low | ||
| DOMAIN 4: Flow and Timing | |||
| Was there an appropriate interval between index test and reference standard? | Yes | ||
| Did all patients receive the same reference standard? | Yes | ||
| Were all patients included in the analysis? | No | ||
| High | |||