Review Article
Is Dementia Screening of Apparently Healthy Individuals Justified?
Table 2
The effect of prevalence on the predictive value of a screening test.
| | Prevalence | | Low (6%) screening | Moderate (30%) case-finding | High (80%) diagnosis |
| Test | Definitive diagnosis of condition | Present | Absent | Total | Present | Absent | Total | Present | Absent | Total |
| Abnormal | 48 | 94 | 142 | 240 | 70 | 310 | 640 | 20 | 660 | Normal | 12 | 846 | 858 | 80 | 630 | 690 | 160 | 180 | 340 | Total | 60 | 940 | 1000 | 300 | 700 | 1000 | 800 | 200 | 1000 |
| | Predictive value of an abnormal test |
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| Hypothetical sensitivity = 80%, specificity = 90% |
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All people on a family health roster. All people in a memory disorder clinic. All people in a locked unit in a long-term care facility.
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