SummerSim 2017: Microsimulation Models for Cost-Effectiveness Analysis: a Review and Introduction to CEAM - Reviewer Wojciech (Al) Chrosny

[Jacob Barhak]

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Review by : Wojciech (Al) Chrosny

Here is my review of the paper #43:

1. Evaluation:  Accept

2. Comments:

The paper presents a good overview of available microsimulation frameworks. The newly developed microsimulation framework (CEAM) seems to be well designed to utilize the available data from Global Burden of Disease (GBD) study and generate results that can be used to compare different treatment strategies. Perhaps in the future papers the team can discuss results of testing CEAM on different disease scenarios and try to compare results with other modelling tools and techniques (e.g. microsimulations in Discrete Event Simulation vs. Discrete Time Markov).  It has been my experience that developing the same model in different tools, can uncover subtle mistakes in one or more approaches resulting in a more robust implementation.

Very specific improvement suggestion with regards to calculation of effective probability (Figure 3 line 13).  The existing line

effective_probability = 1 - np.exp(-effective_rate)

seems to imply time unit of 1.  However in Figure 2 there is a reference to t_timestep parameter.  The time step should most likely be factored into the effective_probability calculation to avoid mistakes that will result when the assumption of unit time = 1 does not hold.

Lastly having an detail knowledge of TreeAge Pro software framework (as director of software engineering at TreeAge Software, Inc.). I want to clarify that TreeAge Pro is available on Unix platforms and it does support distributed parallel computation for microsimulation models.

Best Regards,

Al