There is an inequity in resource utilization among psychiatric in-patients. About 20-30% of them absorb 60-80% of the total resources allocated to this form of treatment. To develop interventions to contain this utilization pattern requires an agreement on a definition of who is a “heavy user”?

Using data from a random sample (n = 15000) from the annual Swiss Hospital Survey we compared different definitions of heavy service use as to their usefulness to map and quantify the effect of interventions targeted to reduce inequity of resource consumption.

To deal with heavy service use necessitates to take a look from different levels of service provision. To create a satisfactory definition that can be generalised across different service systems seems out of reach at an individual level. However, various inequity indices commonly used in economic sciences (e.g. Gini-index) are well suited to specify heavy service use from a systems level.

Quantifying the heavy service use from a systemic level allows for an estimation of the impact of services targeted to contain heavy service use.