Introduction

Economic evaluations of medical technologies assess the effectiveness and cost of the technologies so that physicians, policy makers, and the general public can decide which technologies offer sufficient value for the money. The cost-effectiveness of health care interventions including EMS must be demonstrated definitively if claims of their public health benefit are to have scientific credibility [1]. Since some experts question the merits of interventions to improve resuscitation care [2], while others endorse such interventions [3], we believe that economic evaluations of EMS provide critical information to inform public policy.

Many important outcomes must be considered when evaluating the effectiveness of an intervention. A key outcome consideration is cost (“destitution” in the framework of the “six Ds of outcome”). Although it can be intellectually difficult to consider cost as a health care constraint, the reality is that even when it comes to health care, all resources are finite and selecting the most cost-effective intervention is an important decision.

This chapter will discuss conducting economic evaluation of health interventions in the out-of-hospital setting and will describe a methodology for determining the cost of an EMS intervention to the community it serves that was developed by the EMS Cost Analysis Project (EMSCAP), sponsored by the National Highway Traffic Safety Administration (NHTSA) [4].

State of cost analysis research in EMS

Although EMS research is an emerging field, some projects have worked to establish effectiveness, such as the Ontario Prehospital Life Support Study (OPALS) [5–7]. Interventions such as treatment of non-traumatic cardiac arrest [8–12] and use of a formalized system of care for severe trauma [13–18] are known to be effective. However, little is known about the cost-effectiveness of most EMS interventions.

A structured literature review found that from 2003 to 2013 there were only 60 published economic evaluations of EMS interventions. Only 14 of these evaluations were considered full economic evaluations. Further, using a published checklist for evaluating the quality of an economic evaluation [19], the authors found that most of these studies were of poor quality [20]. They also determined that there were inconsistencies in how EMS costs were measured, indicating the need for a standardized approach to calculating the cost of EMS.

Types of cost analyses

In general, there are four types of cost analyses that are full economic evaluations. The term full economic evaluation means that the costs and the consequences of two or more interventions are compared. The primary difference between the four types of full economic evaluations is how the outcome is measured.

A cost-benefit analysis measures the outcome, or the effect of an intervention, in dollars. For example, Riediger and Fleischmann-Sperber estimated that the annual cost for their EMS system was $8.3 million and that the outcome from providing EMS care was $44.3 million in socioeconomic cost savings to the community [21].

Cost-effectiveness analysis measures a common effect, such as lives saved, between two interventions and reports the result in terms of effect per unit of cost. The effect is measured in natural units such as the amount of disability or health care resources consumed. A common example is the reporting of cost per life saved. For example, Forrer et al. assessed the cost-effectiveness of implementing a police automated external defibrillator program and estimated the cost per life saved ranged from $23,542 to $70,342 and the cost per year of life saved ranged from $1,582 to $16,060 [22].

In a cost-utility analysis the effect is measured in quality-adjusted life-years. For example, Nichol et al. found that the mean incremental cost per quality-adjusted life-year for lay responder defibrillation was $46,700 (95% confidence interval (CI) $23,100 to $68,600) [23].

Finally, a cost-minimization analysis compares two equivalent treatments and determines which has the lowest cost. De Wing et al. used this method and found that burn patients transported by helicopter who could have also been safely transported by ground ambulance had a sevenfold to eightfold increase in transportation charges (assumed to be the actual cost, which is not always a valid assumption in health care research – see later) compared to burn patients transported by ground ambulance [24].