Table 1.

Targets for model calibration

	Literature synthesis	Modeling strategy
Incidence (annual)	High in teenagers – approximately 7.1% in female adolescents, 4.4% in male adolescents. Declines with age.	Use of a Weibull distribution, to reflect declining incidence with age. Separate scale and shape parameters for men and women. Calibrate first incidence to result in lifetime prevalence of approximately 20% for men and 30% for women.
Point prevalence	Overall, approximately 2%. Higher in women than in men, declines with age.	Relative risk of recurrence selected (see below) to predict the point prevalence.
Recurrence	Approximately 10% in first year after recovery from an initial episode. Approximately 85% will have at least one recurrence during their lifetime. Recurrence rate higher after multiple episodes than single episodes.	First recurrence simulated with a Weibull distribution, men and women combined together with a single scale and shape parameter. Relative risk for multiple recurrence was estimated representing a higher risk among those with prior episodes. The relative risk for recurrence was calibrated to achieve a point prevalence of 1.8% holding the Weibull parameters for first incidence and episode duration constant.
Episode duration	Approximately 15% report a 2 week duration, the time at which the diagnosis is technically possible. However, a similar proportion is not recovered after 2 years.	Weibull distribution, a single scale and shape parameter for men and women. Model calibrated by matching the simulated proportion with a two week and 2 year duration at 15% and 85%, respectively.