| Penetrance of a genetic variant |
| Probability that traits or characteristics associated with that variant will manifest (within a specified period of time) |
| |
| Incidence |
| Number of new cases of disease occurring in a population (within a specified period of time) |
| |
| Prevalence |
| Proportion of affected individuals in a population (at a given moment of time)=incidence rate × average duration of disease |
| |
| Sensitivity or detection rate (DR) |
| Proportion of affected individuals (or those who become affected within a specified period of time) with a positive (unfavorable) screening test result |
| |
| Specificity |
| Proportion of unaffected individuals with a negative screening test result |
| |
| False-positive rate |
| Proportion of unaffected individuals with a positive screening test result=1−specificity |
| |
|
DR5
|
| Detection rate for a 5% false-positive rate |
| |
| Positive predictive value (PPV) |
| Risk of disease among individuals with risk factor (with positive screening test result) (clinical impact) |
| |
| Population attributable fraction (PAF) |
| Proportion of cases that could be prevented if the risk factor was absent (the public health impact) |
| |
|
ROQ1−5
|
| Relative odds of the highest fifth of the risk factor distribution compared with people in the lowest fifth |
| |
| Number needed to treat (NNT) |
| Number of people needed to treat for one success |
| |
| Number needed to screen (NNS) |
| Number of individuals needed to screen to prevent one case of disease (measure to assess the performance of screening, combining penetrance and frequency with reduction in risk of disease)=inverse of the frequency divided by the penetrance divided by the reduction in risk of disease=(1/F × p × RR) |
