Reducing an already low dental diagnostic X-ray dose: does it make sense? Comparison of three cost-utility analysis methods used to assess two dental dose-reduction measures

Objectives:
To find a method that is suitable for providing an objective assessment of the cost effectiveness of a dose-reducing measure used for diagnostic dental X-ray exposures.

Methods:
Three cost-utility analysis (CUA) methods were evaluated by comparing their assessments of two dose-reduction measures, a rectangular collimator and the combination of two devices that reduce the radiation dose received during orthodontic lateral cephalography. The following CUA methods were used: (1) the alpha value (AV), a monetary valuation of dose reduction used in the nuclear industry; (2) the value of a statistical life for valuation of the reduction in stochastic adverse effects; and (3) the time-for-time method, based on the postulate that risk reduction is effective when the number of years of life gained is more than the years that an average worker must work to earn the costs of the risk-reducing measure. The CUA methods were used to determine the minimum number of uses that was required for the dose-reducing device to be cost effective. The methods were assessed for coherence (are comparable results achieved for comparable countries?) and adaptability (can the method be adjusted for age and gender of specific patient groups?).

Results:
The performance of the time-for-time method was superior to the other methods. Both types of dose-reduction devices tested were assessed as cost effective after a realistic number of uses with all three methods except low AVs.

Conclusions:
CUA for the methods of X-ray dose reduction can be performed to determine if investment in low dose reduction is cost effective. The time-for-time method proved to be a coherent and versatile method for performing CUA.