I am now writing the discussion section of the paper on the medical care ecology in South Korea. This study adopted the model proposed by Kerr White, a US guru in the health services research field, where the pattern of care utilization is analyzed with a unit of person-month.

Does this practice have any benefit over other approach?

I think the reference period of 'month' fits the rhythm of people's daily living. Although they are paid per week basis in some countries, people in many countries are paid per month. This provides them a kind of living cycle with which people make a plan of their living.

The time length of month is manageable for lay people. It is longer than day and week and shorter than year. In other words, month is long enough to make a plan and is short enough to remember events and manage time. 

We health services researchers use diverse time units depending what an analysis objective is. Despite that, month can be a very natural time unit for analysis when we adopt a user-centered perspective, I think

Would you make any comment on the above or recommend any relevant literature?