Nobili 2008.
| Study characteristics | |||
| Patient sampling | 36 participants with memory complaints in whom an objective memory deficit was demonstrated by means of neuropsychological tests and 17 healthy volunteers who gave their informed consent were recruited during university courses dedicated to elderly people. Sampling procedure not described. We only include data on performance of the index test to discriminate between people with MCI who converted to dementia and those who remained stable. Excusion criteria: presence of analphabetism, major vision disturbances, psychiatric illnesses, epilepsy, major head trauma, Parkinsonism, previous stroke or TIA and brain masses; people scoring higher than 0 on the delusion and the hallucination NPI items were excluded. |
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| Patient characteristics and setting | 36 participants with MCI, diagnosed with the Petersen 2004 criteria at baseline, were recruited from the Outpatient clinic. Demographic characteristics are reported for 33 participants who were included in the analysis. Gender: converters: 11 women, 11 men; non‐converters: 9 women, 2 men Age: converters: 77.3 ± 4.8 years; non‐converters: 74.6 ± 5.4 years APOEɛ4: not reported on all MCI participants. converters: 4/8 (50%); non‐converters: 5/14 (36%) MMSE: converters: 27.6 ± 1.4; non‐converters: 27.4 ± 2.0 Education: converters: 8.5 ± 3.9; non‐converters: 8.8 ± 4.7 Sources of referral: not reported Sources of recruitment: outpatients, no further information |
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| Index tests | ¹⁸F‐FDG PET scan The index test was performed within 3 months from the clinical–neuropsychological examination (mean 29.9 days in participants and 29.8 days in controls). Participants fasted for at least 6 hours. Before radiopharmaceutical injection, blood glucose was checked and was < 140 mg/dl in all cases. After a 10‐min rest in a silent and obscured room, with eyes closed and ears unplugged, participants were injected with approximately 370 MBq of ¹⁸F‐FDG PET via a venous cannula, according to the guidelines of the European Association of Nuclear Medicine (Bartenstein 2002). They remained in the room for 30 mins after injection, and were then moved to the PET room where scanning started approximately 45 mins after injection and lasted 20 mins. Threshold: not reported; visual interpretation ‐ 25 VROI (volumetric region of interest). Index test was conducted before follow‐up. |
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| Target condition and reference standard(s) | Target condition: conversion from MCI to Alzheimer's disease dementia Reference standard: NINCDS‐ADRDA; DSM‐IV. All participants received both reference standards. Unclear whether clinicians conducting follow‐up were aware of the ¹⁸F‐FDG results. |
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| Flow and timing |
Duration of follow‐up: mean 21.1 ± 10.9 months; mean 20.6 ± 10.3 MCI/MCI; mean 22.2 ± 12.4 MCI/ADD At baseline: 36 MCI At follow‐up: 11 converters; 22 non‐converters (Abstract) Number included in analysis: 33 TP = 9; FN = 2; TN = 20; FP = 2 (Table 4, p 2197). Sensitivity: 82%; specificity: 91% (calculated in Review Manager 5) Loss to follow‐up: 3 participants excluded from the analysis: 2 no longer showed any cognitive objective deficit after 26 and 35 months, respectively, and were excluded from the study. Another participant developed fronto‐temporal dementia, according to the current criteria (Knopman 2005) after 1 year and was excluded. |
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| Comparative | |||
| Notes | |||
| Methodological quality | |||
| Item | Authors' judgement | Risk of bias | Applicability concerns |
| DOMAIN 1: Patient Selection | |||
| Was a consecutive or random sample of patients enrolled? | Unclear | ||
| Was a case‐control design avoided? | Yes | ||
| Did the study avoid inappropriate exclusions? | Yes | ||
| Unclear | Low | ||
| DOMAIN 2: Index Test All tests | |||
| Were the index test results interpreted without knowledge of the results of the reference standard? | Yes | ||
| If a threshold was used, was it pre‐specified? | No | ||
| 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? | Unclear | ||
| Unclear | Low | ||
| DOMAIN 4: Flow and Timing | |||
| Was there an appropriate interval between index test and reference standard? | No | ||
| Did all patients receive the same reference standard? | Yes | ||
| Were all patients included in the analysis? | No | ||
| High | |||