The baseline question ("Did you fall in the preceding months?") did not refer to a precise number of months, while the follow-up question ("Did you fall since the preceding examination?") covered a 2-year period.
Progression implies that an individual is initially diagnosed with an early stage of the disease with worsening at the current examination, while regression implies the presence of the disease at the preceding examination with an improvement at the current examination.
New episodes were defined when the preceding examination was AOM, OME or normal.
The number of new lesions in comparison to the preceding examination was counted.
New episodes were defined when the preceding examination was OME or normal.
Disappearance implies the presence of the disease at the preceding examination and its absence at the current examination.
Incidence of the disease implies the appearance of the disease at the current examination when it was absent at the preceding examination.
To calculate the interval from onset of oestrus to ovulation, onset of oestrus and time of ovulation were set retrospectively to the mean time point between first detection and the preceding examination.
If we classify a change in the severity of the disease by defining a three-level scale: disease-free, early and late stage, then different transition courses can be defined as the current disease level conditioning upon the level at the immediately preceding examination.
Prevalence estimates seemed higher when patients were diagnosed without a preceding medical examination.
