Given that NDPs are under complex and multivariate genetic influences and tend to follow a waxing and waning course, a longitudinal twin sample may compromise probabilistic measures, including NPVs and PPVs, since discordant co-twins will be more likely than other pairs to oscillate above or under a cut-off.
The symptoms had persisted more than 15 years with a waxing and waning course.
Clinical behavior after relapse varies from aggressive to indolent, with a waxing and waning course.
Tics occur predominantly in young people (before age 18), and tend to have a waxing and waning course [ 12].
Illness was most frequently mild to moderate in severity, with a waxing and waning course, and all but 2 persons could perform occupational activities.
Chronic cough may follow a waxing and waning course [ 31] and it is possible that the improvement in cough score may be explicable by regression to the mean from the pre study baseline.
We hypothesize that this is partly due to the natural history of the disease: Depression has a waxing and waning course, and disease symptoms that are subject to significant environmental and social effects.
GTS and obsessive-compulsive disorder (OCD) share several characteristics: both disorders have a juvenile or young adult onset, a chronic waxing and waning course and are characterised by the presence of repetitive behaviours (RB) and premonitory urges [3], [4].
34 Due to the waxing and waning course of GAD, it is recommended that treatment continue for at least a year to maximize the probability of remission.
The extreme high values of IL-6 in CSF also during relapses suggest that IL-6 exerts its major functions intrathecally and throughout the waxing and waning course of the disease.
This placebo response has been attributed to the regression to the mean effect, the natural waxing and waning course of epilepsy over time, the likelihood for improved patient care during participation in the trial, and investigator and participant bias [ 53].
