In the study by Fernández-Armenteros et al,1 the authors present a highly efficient way of performing population-based estimates using computerized records. In this case, they used the primary-care database and the database of the dermatology department to estimate that 1.72% of individuals had been diagnosed with psoriasis. This information is very useful for quantifying the magnitude of this problem and supports the information, for example, from the DIADERM Study, in which 4.97% of outpatient consultations were due to psoriasis and 2.49% were follow-up visits—rates that are very similar to outpatient prevalence in a dermatology clinic.2

Despite the convenience of an extensive use of computerized records to calculate estimates for chronic diseases, it should be remembered that there is a risk of certain errors or biases,3 which makes it necessary to thoroughly understand the mechanism and process that generate the information and to analyze the quality of that information. When we have all these factors under control, we can then optimize our data4 to perform different studies. The use of computerized records will, no doubt, increase, especially in studies of prevalence or incidence, and it is therefore important to understand their strengths and weaknesses.

The results of this study will certainly serve to encourage other researchers.