a combined approach for estimating health staff requirements.

many studies have been carried out and many methods have been used for estimating health staff re-quirements in health facilities or system, each have different advantages and disadvantages. differences in the extent to which utilization matches needs in different conditions intensify the limitations of each approach when used in iso-lation. is the utilization-based approach efficient in a situation of over servicing? is it sufficient in a situation of under-utilization? these questions can be similarly asked about the needs-based approach. this study is looking for a flexible approach to estimate the health staff requirements efficiently in these different conditions.this study was carried out in 2011 in some stages: it was conducted in order to identify the formula used in the different approaches. the basic formulas used in the utilization-based approach and the needs-based approach were identified and then combined using simple mathematical principles to develop a new formula. finally, the new formula was piloted by assessing family health staff requirements in the health posts in kashan city, iran.comparison of the two formulas showed that the basic formulas used in the two approaches can be com-bined by including the variable 'coverage'. the pilot study confirmed the role of coverage in the suggested combined approach.the variables in the developed formula allow combining needs-based, target-based and utilization-based approaches. a limitation of this approach is applicability to a given service package.