A trend analysis of surgical operations under a global payment system in Tehran, Iran (2005-2015)

Global payment system is a first example of per-case payment system that contains 60 commonly used surgical operations for which payment is based on the average cost per case in Iran.

The aim of the study was to determine the amount of reduction, increase or no change in the trend of global operations.

In this retrospective longitudinal study, data on the 60 primary global surgery codes was gathered from Tehran Health Insurance Organization within the ten-year period of 2005-2015 separately, for each month. Out of 60 surgery codes, only acceptable data for 46 codes were available based on the insurance documents sent by medical centers. A quantitative analysis of time series through Regression Analysis Model using STATA software v.11 was performed.

Some global surgery codes had an upward trend and some were downwards. Of N Codes, N83, N20, N28, N63, and N93 had an upward trend (p<0.05) and N32, N43, N81 and N90 showed a significant downward trend (p<0.05). Similarly, all H Codes except for H18 had a significant upward trend (p<0.000). As such, K Codes including K45, K56 and K81 had an increasing movement. S Codes also experienced both increasing and decreasing trends. However, none of the O Codes changed according to time. Other global surgical codes like C61, E07, M51, L60, J98 (p<0.000), I84 (p<0.031) and I86 (p<0.000) shown upward and downward trends. Total global surgeries trend was significantly upwards (B=24.26109, p<0.000).

The varying trend of global surgeries can partly reflect the behavior of service providers in order to increase their profits and minimize their costs.