The economic analysis provides information from a series of patients whose routine care was carried out using a store-and-forward teledermatology system and conventional referral system for presurgical assessment in a Portuguese public healthcare setting equipped with intranet.
In the context of the regional hospital setting and the patients’ perspective adopted in the analysis, this study shows store-and-forward teledermatology to be an economically advantageous method for the patients involved in the presurgical assessement and management. Considerable differences were found between the out-of-pocket expenses using presurgical TD and the conventional process. Overall, presurgical TD was 2.12 times less costly than the conventional referral system for patients having surgical intervention (€30.02 per patient compared to €63.71 per patient). Table 3 also shows that the expenses fell substantially among patients with Squamous Cell Carcinoma, making presurgical TD 2.75 times less costly than conventional care (€26.33/patient compared to €72.33/patient). For patients with Basal Cell Carcinoma, presurgical TD is 1.75 times less costly than conventional care.
In the 123 cases in this study, the mean age of the patients was 68.64 years (95% confidence interval [CI], 66.04–71.24 years; range 22–94 years), and there were approximately the same number of men (50.4%) as women (49.6%), see Table 1. The observed difference between the sample means is not considerable to say that the average age and gender between presurgical TD and conventional referral patients differ. Patients who were managed using teledermatology made on average one visit before surgical intervention. Presurgical CR patients made on average two visits before surgery. The mean time to surgical intervention for the patients managed by presurgical TD was 86.09 days. In the group managed using the conventional process, mean time to surgery was 126.11 days.
There were 15 patients using teledermatology who were called for an extra visit to the hospital before surgical intervention, and four patients using conventional care who were called for an extra visit. Systematic reviews show that there is good diagnostic agreement when comparing a teledermatology diagnosis and in-person clinical diagnosis or histopathology with traditional face-to-face consultations . However, several factors may directly impact the reliability of teledermatology, including proper imaging, comprehensive relevant history, and skills of the teledermatologists and referring physicians . The difference of extra visits between the two systems could reflect the fact that a lack of sufficient information to plan the surgical intervention is more frequent in teledermatology than in the conventional method.
The economic results of the use of teledermatology have been analyzed in earlier studies [2, 4,5,6, 25, 33]. From the point of view of out-of-pocket expenses, there has been no prior analysis of the use of teledermatology in presurgical assessment and management. The economic analysis of presurgical teledermatology in patients with nonmelanoma skin cancer by Ferrándiz et al.  found the conventional system to be 1.78 times more expensive than presurgical teledermatology. However, comparisons to their results should not be made because their travel costs took into account the type of transportation used (public, private, or medical transport) and the cost incurred through loss of wages used the minimum wage. Also, their study included direct and indirect healthcare costs.
The expenses relative to wait time difference suggested a €0.74 saving per patient and per day of wait time avoided for patients using presurgical TD. This saving was substantially greater for patients with Squamous Cell Carcinoma and lower for patients with Basal Cell Carcinoma (€4.35 and €0.38 per patient and per day of wait time avoided, respectively). The saving was greater among patients with Squamous Cell Carcinoma because this calculation is based on the reduction in wait time. Patients with Squamous Cell Carcinoma generally required close medical follow-up, giving rise to a reduction in the difference of waiting times between the two modalities, decreasing the mean wait time difference. Furthermore, two patients with Squamous Cell Carcinoma under presurgical TD system required an extra visit to the hospital, which made it more expensive, and thus closer to conventional care.
The study has several limitations, the most important of which concerns the quality of data entered into the model. It was assumed that all patients traveled by taxi, and some patients may have traveled by other means of transportation, namely bus or private transport. This may overestimate the transport cost, as taxis are an expensive means of transportation when compared to public or private transport. Patients who had difficulties in traveling to the hospital (bedridden patients and those in other incapacitating situations) and who required home treatment and medical transport were not taken into account. This may underestimate the travel cost. Companions of patients were not taken into account in the calculation of the expense associated with travel and lost wages. This may underestimate the out-of-pocket expenses. Unemployed and or chronically ill patients were not taken into account when calculating the opportunity cost of visits. This may have overestimated the opportunity cost. The real patient salaries and exact time spent traveling to, from, and during visits were not available, so the opportunity cost was calculated based on average wages and average time spent on visits, which weakens the validity of the results. Finally, the allocation of patients to the subgroups was not random and, therefore one has to be attentive to the potential bias in the analysis between subgroups. Despite these drawbacks, which are typical of most model-based economic evaluations, our study helps to clarify the often contradictory research in the field of economic evaluation of teledermatology.
This study would benefit from the greater accuracy of data that a prospective study would afford. In particular, a prospective study would allow knowing how to quantify the value of time, especially for the unemployed and retired patients. It would also allow studying the impact of teledermatology on the quality of life and the quality of care attached to teledermatology as perceived by the patients.