Parnetti 2006.
| Study characteristics | |||
| Patient sampling | 273 consecutive patients with a suspected cognitive impairment were referred by GPs or other specialists to an out‐patient memory clinic during the period January 2001 to June 2003. Exclusion criteria: patients fulfilling clinical and neuroradiological criteria for subcortical ischaemic vascular dementia were excluded; patients with secondary cases of cognitive impairment were also excluded. No further exclusion criteria were defined |
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| Patient characteristics and setting | 55 MCI participants were diagnosed by the Petersen 1999 criteria at baseline Gender: not reported Age: not reported APOE ϵ4 carrier: not reported MMSE: not reported Setting: secondary care, memory clinic, Perugia, Italy |
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| Index tests | CSF: Abeta42 CSF was centrifuged for 10 min at 4000 g, then stored at ‐80ºC until analysis. Abeta 42 was assessed using a commercial ELISA (Innotest b‐amyloid 1–42, Innogenetics). Threshold(s): 500 pg/l; determined at baseline and based on published criteria (p130) At baseline 55 participants: 47 with 'normal CSF Abeta1‐42 level'; 8 with 'abnormal CSF Abeta1‐42 level' Index test was conducted before clinical follow‐up |
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| Target condition and reference standard(s) | Target condition: Alzheimer's disease dementia Reference standard: NINCDS‐ADRDA criteria Unclear whether clinicians conducting follow‐up were aware of CSF biomarker results |
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| Flow and timing |
Duration of follow‐up: 12 months At follow‐up: 55 MCI: 11 MCI‐AD; 33 MCI‐MCI (stable); 11 participants showed a further progression of cognitive impairment, still not fulfilling the diagnostic criteria for dementia (p130) Number included in analyses=55: 11 MCI‐ADD; 44 MCI‐non‐converters; Sensitivity 36%; Specificity 91% (p131) TP=4, FP=4; FN=7; TN=40 Loss to follow‐up: CSF marker and follow‐up data appeared to have been available for all participants |
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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? | Yes | ||
| Was a case‐control design avoided? | Yes | ||
| Did the study avoid inappropriate exclusions? | Unclear | ||
| Low | 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 | ||
| High | |||