The costutility analysis was performed from the perspective of a health care system with a time horizon of 12 months. It was focused on calculating the incremental costeffectiveness ratio (ICER) of the intervention and comparing it to the standard of care. As for secondary outcomes, the analysis also calculates the Willingness to Pay (WTP).
Model and base case
As previously mentioned, the use case takes into account the threestate Markov model depicted in Fig. 1.
Each health state describes institutionalized patients between 65 and 90 years of age. The baseline health state describes patients without dementia whereas the deteriorated health state describes patients with dementia. Records show that the prevalence of dementia in institutionalized patients in our reference area is 40%. This is adopted as the incidence rate for both the control and intervention group since the intervention does not focus on reducing the rate of incidence of dementia and therefore does not affect it. In this use case, it was assumed that patients cannot completely recover once they already have dementia and, thus, recovery rates were set to 0 for both groups. (Transition probabilities: intervention and control group, incidence rate: 40 and recovery rate: 0).
Mortality rate estimates were derived from the findings of the DARTAD (2) clinical trial, which reported higher survival rates in patients who were given placebo drugs instead of neuroleptics. Based on the clinical trial, the cumulative probability of survival at 12 months was 70% in the control group (those who continued treatment with neuroleptics) vs. 77% in the intervention group (those who were given placebos). Moreover, the results show that the difference between the groups was greater after longer periods: at 24 months, survival rate was 46% vs. 71% and at 36 months, it was 30% vs. 59%. The mortality rates were obtained by first calculating the mean of all the survival rates given (49% vs. 69% or 0.49 vs. 0.69) and then subtracting the mean survival rates from 1. (Calculated mortality rate: 0.51 vs. 0.31).
The MAFEIP tool uses another measure for estimating mortality in a given population: the relative risk of mortality (RR). This is calculated by dividing the mortality rates in the use case by the mortality for a reference condition. In this particular use case, the reference condition is the agedependent, allcause mortality of the Spanish population as recorded in the Human Mortality Database. The RR values were a baseline health of 1 and deteriorated health of 1.31 for the intervention group, and 1 and 1.51 for the control group, respectively.
Patients in the baseline health state had an RR of 1. This is the default value and it prompts the tool to simply use data that is stored in the Human Mortality Database. Those in the deteriorated health state, however, were given an RR greater than 1. Choosing the value RR > 1 leads the tool to interpret this as excess mortality to be added to the existing data from the Human Mortality Database (i.e., mortality rate from database + excess mortality from use of neuroleptics).
Across all patient groups, those who had dementia (deteriorated state) and were given neuroleptics (control group) had the highest mortality rate (1.51 is higher than baseline and higher than the intervention group). Mean patient age was 87.09 years (SD: 6.795), and 75% (n = 180) were women. There were no significant differences in patient age between the participating nursing homes.
Computing the costs
Intervention cost estimates were based on the amount of time spent by the physician, pharmacist, and/or nurse with the patients. The total sum of intervention costs calculated from the staff spending 30 minutes with each patient, in accordance with the therapeutic plan, came to €11,654.40 or €48.56 per patient. Since the patient does not have to pay for the therapeutic guide itself before it is used, the intervention oneoff costs were left at 0.
Cost estimates described the average healthcare costs per dementia patient per year as ranging from approximately €3,596.88 to €5,130.90. An example of such costs is presented in the Table 1, adapted from socialeconomic studies of Alzheimer disease and vascular dementia patients based in Spain (35) (37). These are only select examples of the potential costs of a dementia patient. Caregiver costs have not been included.
Table 1
Sample of annual healthcare and societal costs per dementia patient, taken from the literature
Sample healthcare costs (direct costs) in EUR in different areas in Spain
|
Hospital care
|
619
|
1,706
|
1,687
|
Medical visits (public and private)
|
247
|
237
|
349
|
Medical tests and examinations
|
131
|
139
|
176
|
Emergencies
|
68
|
-
|
-
|
Nursing home care
|
67
|
-
|
-
|
Orthopedic devices
|
231
|
-
|
-
|
Healthcare transport
|
62
|
13
|
264
|
Drugs
|
1,836
|
771
|
833
|
However, for this use case, the intervention specifically aimed to reduce the amount of neuroleptic drugs given to patients. A study of the costs of this intervention included a medication review that compared drugrelated costs of the patients before, during, and after the use of the intervention. For this reason, only drugrelated costs were considered in the MAFEIP tool. Drugrelated costs per patient were calculated to be €2,265.68 before the intervention, €1,720.77 at one month after intervention and €1,539.90 at six months after the intervention. All other costs were considered constants. The table below summarizes the results of the medication review. These are transferred to the MAFEIP tool as follows:
Table 2
Healthcare and societal costs (drugrelated) as MAFEIP input
|
Control Group
|
Intervention Group
|
Healthcare costs baseline health
|
0
|
0
|
Societal costs baseline health
|
0
|
0
|
Healthcare costs deteriorated health
|
€2,266
|
€1,630
|
Societal costs deteriorated health
|
€2,266
|
€1,630
|
As shown in the Table 2, baseline health costs were left at 0 since the intervention only focuses on patients that are already in a deteriorated health state (they already have dementia). Since the use case focused on comparing costs related to drug use for institutionalized dementia patients, additional societal costs such as transport were not taken into account (e.g. if they live far away and have to drive to another city to be admitted to a hospital or the costs of relatives acting as caretakers at home). Thus, in this example, societal costs are the same as the healthcare costs.
The costs of the intervention group were calculated as the mean of the costs recorded after intervention.