- behavioural addiction
- positive predictive value
- negative predictive value
Survey-based studies often fail to take into account the predictive value of a test, in other words, the probability of a person having (or not having) the disease when scoring positive (or negative) on the given screening test.
In general, the lower the prevalence the worse the predictive value is. When the disorder is relatively rare, a positive test finding is typically not useful in confirming its presence given the high proportion of false positive cases. For example, using the Compulsive Buying Scale (Faber & O’Guinn, 1992) three in four people classified as having compulsive buying disorder will in fact not have the disorder.