Diagram of the simplified version of the POHEM-OA used for the uncertainty analysis example. POHEM-OA: Population Health Microsimulation model for osteoarthritis (OA) [46]. Rectangles inside the figure are data sets used for estimation of parameters; first in top left: NPHS 1994–2004: National Population Health Survey, a longitudinal household survey by statistics Canada with a sample of size of over 17,000 persons that started in 1994 [49], 5 cycles (1996–2006) have been used in BMI trajectory model and two cycles (2000–2002) used in estimation of relative risks (hazard ratios) of OA. **Rectangle in the bottom left corner: CCHS 2001 (Canadian Community Health Survey [50]) used for generating the starting population for the microsimulation with characteristics listed on the left column of the figure. **Rectangle in the bottom right corner: Pop-data BC (population data BC [49]): administrative billing data for the province of BC including data for >98% residents of BC from 1994–2003, used for estimating incidence of OA.