2. Review of methods for estimating the costs of illness

This section introduces the existing COI studies in terms of their research designs, data selection and value assessment processes, applied perspectives, and chosen components of costs.

#### 2.1 Study designs

COI studies can be roughly divided into two groups, depending on the approaches they adopted to estimate the socioeconomic costs of illnesses. These two approaches are the incidence-based approach and prevalence-based approach [1–3].

## 2.1.1 Incidence-based approach

The incidence-based approach involves estimating the socioeconomic cost of a given illness throughout the entire lifespan of the illness, from its initial stage to the patient's complete recovery or death. This involves estimating not only the economic burden currently imposed by the illness but also the cost of future healthrelated losses, including those caused by sequela. This approach allows the researcher to identify economic losses over time, from the present into the future, but makes it impossible to take into account patients who have already suffered from the same disease. In other words, the incidence-based approach may not be well suited to estimating the economic burdens of certain types of illnesses (i.e., those that currently have low incidence rates but high prevalence rates) at certain moments in time.

#### 2.1.2 Prevalence-based approach

Contrary to the incidence-based approach, the prevalence-based approach considers economic burdens accruing from not only existing patients suffering from a given illness for a fixed period of time but also from future and potential patients. This approach is well suited to estimating the economic costs of an illness at certain points in time but may not allow the researcher to estimate the cost accrued throughout the lifespan of the illness, from its initial stage to the patient's complete recovery (or death). Furthermore, this approach may not be so amenable to estimating the costs of frequent yet short-lived illnesses that do not last long enough for the researcher to find and identify suitable patients within a given period of time.

The prevalence-based approach is by far the more popular method used in previous studies. This is because it is important to take into account both new and existing patients suffering from the given illnesses in order to estimate the socioeconomic costs of those illnesses during certain periods.

The characteristics and pros and cons of these two approaches are summarized below (Table 1).

Methodology of Estimating Socioeconomic Burden of Disease Using National Health Insurance… DOI: http://dx.doi.org/10.5772/intechopen.89895


Table 1.

Comparison of approaches to estimating the socioeconomic costs of illnesses.
