Galluzzi 2010.

Study characteristics
Patient sampling	108 consecutive participants with MCI, referred to an outpatient memory clinic over 24 months, were initially selected. Finally, 90 participants were included. Of these, only 38 underwent ¹⁸F‐FDG PET scan. The other 52 did not undergo ¹⁸F‐FDG PET because of refusal (n = 25), contraindications (n = 7) or because they had previously undergone a brain perfusion study with 99mTc‐ECD SPECT (n = 20). Exclusion criteria: not specified.
Patient characteristics and setting	38 MCI participants with ¹⁸F‐FDG scan. Diagnostic criteria for MCI were not directly specified. However, it can be inferred that the authors use the Petersen 1999 criteria. MCI is defined as the presence of objective impairment in memory or other cognitive domains (performance lower than the 5th percentile on neuropsychological tests applied in the study) in the absence of functional impairment. Demographic data reported on all 90 participants included in the study. Gender: 53 women, 37 men AGE: MCI‐NC: 70.9 ± 7.1 years; MCI‐ADD: 72.2 ± 7.1 years; MCI‐non‐ADD; 73.0 ± 7.1 years APOEɛ4: MCI‐NC: 19 (41%); MCI‐ADD: 14 (58%); MCI‐nADD: 2 (15%). The data refer to 35 participants in total. It is not reported how many or which of them underwent PET scan MMSE: MCI‐NC: 26.3 ± 1.9; MCI‐ADD: 26.4 ± 1 .6; MCI‐non‐ADD: 25.5 ± 1.9 Education: MCI‐NC: 7.7 ± 3.6; MCI‐ADD: 8.8 ± 4.6; MCI‐non‐ADD: 7.3 ± 4.0 Sources of referral: not reported Sources of recruitment: Translational Outpatient Memory Clinic (TOMC), at the National Institute for the Research and Care of Alzheimer’s Disease (IRCCS Centro San Giovanni di Dio Fatebenefratelli), Brescia, Italy
Index tests	¹⁸F‐FDG PET scan The authors did not give details regarding radiopharmaceutical (¹⁸F‐FDG) administration. However, they report on evaluation criteria applied in PET reading. As it is written in text: "FDG uptake was assessed with the automated version (PALZ score of PMOD technologies) of the t sum score developed by Herholz and colleagues for the diagnosis of AD, combining the virtues of voxel‐based parametric mapping with the diagnostic information on brain regions that are typically affected in AD. Briefly, the ¹⁸F‐FDG PET image of an individual patient is compared to a database of normal controls and the voxel‐by‐voxel sum of t scores in an AD‐pattern mask is computed. Abnormal ¹⁸F‐FDG PET was defined following the original indications of a t sum higher than 11,090" (p 2007). Threshold: ¹⁸F‐FDG PET positive: t sum > 11.090 (Herholz 2002); prespecified. Index test was conducted before follow‐up.
Target condition and reference standard(s)	Target condition: conversion from MCI to Alzheimer's disease dementia or other forms of dementia Reference standard: NINCDS‐ADRDA criteria Unclear whether clinicians conducting follow‐up were aware of the ¹⁸F‐FDG results.
Flow and timing	Duration of follow‐up: MCI‐NC: 26.5 ± 16.0 months; MCI‐ADD: 21.5 ± 10.2 months; MCI‐non‐ADD: 19.1 ± 8.9 months The data refer to all 90 people with MCI, not only to the 38 who underwent PET scan. Information from the author: At baseline: 28 ¹⁸F‐FDG test positive; 10 ¹⁸F‐FDG negative At follow‐up: 28 with abnormal ¹⁸F‐FDG PET scan: 15 MCI‐converters (11 MCI‐ADD; 4 MCI non‐ADD) and 13 MCI‐non‐converters (13 MCI‐MCI); 10 with normal ¹⁸F‐FDG PET scan: 3 MCI‐converters (3 MCI‐ADD; 2 MCI‐non‐ADD) and 5 MCI‐non‐converters (5 MCI‐MCI). Number included in analysis: 38 TP = 15; FN = 5; FP = 13; TN = 5 (conversion to All dementia) TP = 11; FN = 3; FP = 17; TN = 7 (conversion to ADD) TP = 4; FN = 2; FP = 24; TN = 8 (conversion to non‐ADD dementia) Loss to follow‐up: none for 38 MCI participants with ¹⁸F‐FDG scan Lost to follow‐up for the initial sample: 52 (25 participants refuse the ¹⁸F‐FDG PET scan; 7 were not performed because of contraindications and 20 because they had previously undergone 99mTc‐ECDSPECT scan). In addition,18 participants were excluded from the consecutive sample (N = 108): 16 due to refusal of follow‐up; 2 due to logistical problems.
Comparative
Notes	We contacted the trial investigators who provided relevant data tor the 2 x 2 table to be completed (email on 23rd August 2013).
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
		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?	Yes
		Low	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?	Yes
		Low